From fcdcd45da91dd9d9584561d79d4c449fb2819a98 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Mon, 10 Apr 2023 14:14:18 +0200
Subject: [PATCH 01/22] make some changes regarding what rights media editors
 have

---
 app/abilities/lecture_ability.rb          |  2 +-
 app/abilities/quiz_certificate_ability.rb |  2 +-
 app/abilities/tutorial_ability.rb         |  2 +-
 app/abilities/user_ability.rb             |  8 ++++--
 app/assets/javascripts/lectures.coffee    |  1 -
 app/controllers/media_controller.rb       |  4 +--
 app/controllers/users_controller.rb       |  5 ----
 app/models/lecture.rb                     | 10 +++++++
 app/models/medium.rb                      | 17 ++++++++++--
 app/models/user.rb                        | 16 +++++++++--
 app/views/lectures/edit/_form.html.erb    |  6 +++--
 app/views/lectures/edit/_people.html.erb  |  3 ++-
 app/views/media/_basics.html.erb          | 33 +++++++----------------
 app/views/users/list.json.jbuilder        |  4 ---
 config/locales/de.yml                     |  4 +--
 config/locales/en.yml                     |  7 ++---
 config/routes.rb                          |  6 +----
 17 files changed, 72 insertions(+), 58 deletions(-)
 delete mode 100644 app/views/users/list.json.jbuilder

diff --git a/app/abilities/lecture_ability.rb b/app/abilities/lecture_ability.rb
index 5480923c4..c465cd87d 100644
--- a/app/abilities/lecture_ability.rb
+++ b/app/abilities/lecture_ability.rb
@@ -33,7 +33,7 @@ def initialize(user)
     end
 
     can :subscribe_page, Lecture do |lecture|
-      lecture.published? || !user.generic?
+      lecture.published? || user.can_edit_teachables?
     end
   end
 end
\ No newline at end of file
diff --git a/app/abilities/quiz_certificate_ability.rb b/app/abilities/quiz_certificate_ability.rb
index 206827a25..ec494aec4 100644
--- a/app/abilities/quiz_certificate_ability.rb
+++ b/app/abilities/quiz_certificate_ability.rb
@@ -7,7 +7,7 @@ def initialize(user)
     can :claim, QuizCertificate
 
     can :validate, QuizCertificate do
-      user.tutor? || !user.generic?
+      user.tutor? || user.can_edit_teachables?
     end
   end
 end
\ No newline at end of file
diff --git a/app/abilities/tutorial_ability.rb b/app/abilities/tutorial_ability.rb
index d17014db1..260a09b40 100644
--- a/app/abilities/tutorial_ability.rb
+++ b/app/abilities/tutorial_ability.rb
@@ -24,7 +24,7 @@ def initialize(user)
     end
 
     can :validate_certificate, Tutorial do
-      user.tutor? || !user.generic?
+      user.tutor? || user.can_edit_teachables?
     end
   end
 end
diff --git a/app/abilities/user_ability.rb b/app/abilities/user_ability.rb
index 77356b1fd..506fcb944 100644
--- a/app/abilities/user_ability.rb
+++ b/app/abilities/user_ability.rb
@@ -14,8 +14,12 @@ def initialize(user)
       user.admin? || (!user.generic? && user == given_user)
     end
 
-    can [:fill_user_select, :list, :list_generic_users], User do
-      !user.generic?
+    can :fill_user_select, User do
+      !user.can_edit_teachables?
+    end
+
+    can :list_generic_users, User do
+      user.admin?
     end
   end
 end
\ No newline at end of file
diff --git a/app/assets/javascripts/lectures.coffee b/app/assets/javascripts/lectures.coffee
index d47ede273..7fe308c6e 100644
--- a/app/assets/javascripts/lectures.coffee
+++ b/app/assets/javascripts/lectures.coffee
@@ -187,7 +187,6 @@ $(document).on 'turbolinks:load', ->
         lecture: lectureId
       }
       success: (result) ->
-        $('#lectureUserCounter').append(result.length)
         $('#lectureUserModalButton').hide() if result.length == 0
         for u in result
           row = document.createElement('div')
diff --git a/app/controllers/media_controller.rb b/app/controllers/media_controller.rb
index 3f4c03d8a..a3dbe1560 100644
--- a/app/controllers/media_controller.rb
+++ b/app/controllers/media_controller.rb
@@ -213,7 +213,7 @@ def search
     authorize! :search, Medium.new
 
     # get all media, then set them to only those that are visible to the current user
-    if current_user.generic? || search_params[:access].blank?
+    if !current_user.can_edit_teachables? || search_params[:access].blank?
       filter_media = true
       params["search"]["access"] = 'irrelevant'
     end
@@ -224,7 +224,7 @@ def search
     results = search.results
     @total = search.total
 
-    # in the case of a search with tag_operator 'or', we 
+    # in the case of a search with tag_operator 'or', we
     # execute two searches and merge the results, where media
     # with the selected tags are now shown at the front of the list
     if search_params[:tag_operator] == "or" and search_params[:all_tags] == "0" and search_params[:fulltext].size >= 2
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 41889d377..a60f05ff9 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -48,11 +48,6 @@ def elevate
     end
   end
 
-  def list
-    search = User.search { fulltext params[:term] }
-    @users = search.results
-  end
-
   def list_generic_users
     result = User.where.not(id: @elevated_users.pluck(:id))
                  .values_for_select
diff --git a/app/models/lecture.rb b/app/models/lecture.rb
index 4f510aecf..b1d288c23 100644
--- a/app/models/lecture.rb
+++ b/app/models/lecture.rb
@@ -771,6 +771,16 @@ def import_toc!(imported_lecture, import_sections, import_tags)
     end
   end
 
+  def speakers
+    return User.none unless seminar?
+    User.where(id: SpeakerTalkJoin.where(talk: talks).pluck(:speaker_id))
+  end
+
+  def older_than?(timespan)
+    return true unless term
+    term.begin_date < Term.active.begin_date - timespan
+  end
+
   private
 
   # used for after save callback
diff --git a/app/models/medium.rb b/app/models/medium.rb
index 687e24a37..af326c2b8 100644
--- a/app/models/medium.rb
+++ b/app/models/medium.rb
@@ -282,7 +282,7 @@ def self.search_by(search_params, page)
                                                    .teachables_as_strings
     search_params[:editor_ids] = [] if search_params[:all_editors] == '1' || search_params[:all_editors].nil?
     # add media without term to current term
-    
+
     search_params[:all_terms] = '1' if search_params[:all_terms].blank?
     search_params[:all_teachers] = '1' if search_params[:all_teachers].blank?
     search_params[:term_ids].push('0') if search_params[:term_ids].present?
@@ -454,6 +454,19 @@ def editors_with_inheritance
     (result + teachable.speakers).uniq
   end
 
+  # returns the array of users that are eligible to obtain editing rights
+  # for the given medium from the given user
+  def eligible_editors(user)
+    result = editors_with_inheritance
+
+    if teachable.is_a?(Talk) && user.can_edit?(lecture)
+      result += lecture.speakers
+    end
+
+    result << user if user.admin?
+    result.uniq
+  end
+
 
   # creates a .vtt tmp file (and returns it), which contains
   # all data needed by the thyme player to realize the toc
@@ -1201,5 +1214,5 @@ def answers_count
     return -1 unless type == 'Question'
     becomes(Question).answers.count
   end
-  
+
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index 58a29840f..c29d88f44 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -293,10 +293,22 @@ def teacher?
     given_lectures.any?
   end
 
+  def teachable_editor?
+    edited_courses.any? || edited_lectures.any?
+  end
+
+  def teachable_editor_or_teacher?
+    teachable_editor? || teacher?
+  end
+
+  def can_edit_teachables?
+    admin? || teachable_editor_or_teacher?
+  end
+
   # a user is an editor iff he/she is a course editor or lecture editor or
   # editor of media that are not associated to talks
   def editor?
-    edited_courses.any? || edited_lectures.any? ||
+    teachable_editor ||
       edited_media.where.not(teachable_type: 'Talk').any?
   end
 
@@ -525,7 +537,7 @@ def subscribe_lecture!(lecture)
     return false unless lecture.is_a?(Lecture)
     return false if lecture.in?(lectures)
     lectures << lecture
-    
+
     # make sure subscribed_users is updated in media
     Sunspot.index! lecture.media
 
diff --git a/app/views/lectures/edit/_form.html.erb b/app/views/lectures/edit/_form.html.erb
index 1daabd7d3..1502ac284 100644
--- a/app/views/lectures/edit/_form.html.erb
+++ b/app/views/lectures/edit/_form.html.erb
@@ -54,8 +54,10 @@
   <%= render partial: 'announcements/modal' %>
   <%= render partial: 'lectures/publish/publish',
              locals: { lecture: lecture } %>
-  <%= render partial: 'lectures/edit/user_modal',
-             locals: { lecture: lecture } %>
+  <% unless lecture.older_than?(1.year) %>
+    <%= render partial: 'lectures/edit/user_modal',
+               locals: { lecture: lecture } %>
+  <% end %>
   <% if !lecture.seminar? || lecture.legacy_seminar %>
     <%= render partial: 'chapters/modal',
                locals: { lecture: lecture } %>
diff --git a/app/views/lectures/edit/_people.html.erb b/app/views/lectures/edit/_people.html.erb
index 5361d395d..fb1b53472 100644
--- a/app/views/lectures/edit/_people.html.erb
+++ b/app/views/lectures/edit/_people.html.erb
@@ -81,9 +81,10 @@
             <div class="col-12">
               <%= t('basics.subscribers_count_nc') %>
               <span id="lectureUserCounter">
+                <%= lecture.users.count %>
               </span>
               <%= helpdesk(t('admin.lecture.info.subscribers_count'), false) %>
-              <% if lecture.users.any? %>
+              <% if lecture.users.any? && !lecture.older_than?(1.year)%>
                 <button type="button"
                         id="lectureUserModalButton"
                         class="ml-3 btn btn-outline-primary btn-sm"
diff --git a/app/views/media/_basics.html.erb b/app/views/media/_basics.html.erb
index 848a80ccb..a52556d0d 100644
--- a/app/views/media/_basics.html.erb
+++ b/app/views/media/_basics.html.erb
@@ -54,30 +54,15 @@
       <%= f.label :editor_ids,
                   t('basics.editors') %>
       <%= helpdesk(t('admin.medium.info.editors'), true) %>
-      <% if current_user.admin || current_user.editor? %>
-        <%= f.select :editor_ids,
-                     options_for_select(add_prompt(medium.editors
-                                                         .map { |e| [e.info, e.id] }),
-                                        medium.editors.map(&:id)),
-                     {},
-                     { multiple: true,
-                       class: 'selectize',
-                       style: 'display: none;',
-                       data: { ajax: true,
-                               filled: false,
-                               model: 'user',
-                               placeholder: t('basics.enter_two_letters'),
-                               no_results: t('basics.no_results') } } %>
-      <% else %>
-        <%= f.select :editor_ids,
-                     options_for_select((medium.teachable.speakers | medium.editors).map { |e| [e.info, e.id] },
-                                        medium.editors.map(&:id)),
-                     {},
-                     { multiple: true,
-                       class: 'selectize',
-                       style: 'display: none;',
-                       data: { ajax: false } } %>
-      <% end %>
+      <%= f.select :editor_ids,
+                   options_for_select(medium.eligible_editors(current_user)
+                                            .map { |e| [e.info, e.id] },
+                                      medium.editors.map(&:id)),
+                   {},
+                   { multiple: true,
+                     class: 'selectize',
+                     style: 'display: none;',
+                     data: { ajax: false } } %>
       <div class="invalid-feedback"
            id="medium-editors-error">
       </div>
diff --git a/app/views/users/list.json.jbuilder b/app/views/users/list.json.jbuilder
deleted file mode 100644
index 87cfb45e1..000000000
--- a/app/views/users/list.json.jbuilder
+++ /dev/null
@@ -1,4 +0,0 @@
-json.array! @users do |user|
-  json.id user.id
-  json.text user.tutorial_info
-end
\ No newline at end of file
diff --git a/config/locales/de.yml b/config/locales/de.yml
index f1013d8a3..b94370128 100644
--- a/config/locales/de.yml
+++ b/config/locales/de.yml
@@ -1140,7 +1140,7 @@ de:
           Dies die Liste aller Personen, die für dieses Medium
           als Editor verantwortlich sind. Es muss mindestens eine angegeben
           werden, jede dieser Personen erhält das Bearbeitungsrecht für das
-          Medium.
+          Medium. Es stehen nur Personen zur Auswahl, die berechtigt sind.
           <br>
           Anmerkung: Unabhängig davon kann das Medium auch von Personen mit
           höheren Rechten bearbeitet werden, beispielsweise von ModuleditorInnen
@@ -2052,7 +2052,7 @@ de:
     data_request: >
       Daten anfordern
     data_request_sent: >
-      Wir haben deine Anfrage erhalten und werden dir deine Daten zeitnah schicken. 
+      Wir haben deine Anfrage erhalten und werden dir deine Daten zeitnah schicken.
   mampf_news:
     title: 'MaMpf-News'
     check_notifications: 'Alle erledigen'
diff --git a/config/locales/en.yml b/config/locales/en.yml
index d2acf1cc1..04cde8f4a 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -1082,7 +1082,8 @@ en:
         editors: >
           This is the list of all persons that are responsible for this
           medium as editor. At least one person has to be given here, and each
-          of these persons gets editing access to this medium
+          of these persons gets editing access to this medium. Only eligible
+          persons can be selected.
           <br>
           Note: Independently from this setting, this medium can be edited
           by people with hiher access rights, e.g. editors of the associated
@@ -2357,7 +2358,7 @@ en:
       title: >
         You can search the titles of media or related sessions. If you do not wantto use
         this criterion, leave the input box empty.
-      title_placeholder: leave free or enter at least 2 letters 
+      title_placeholder: leave free or enter at least 2 letters
       lectures: >
         Select the event series you want to search. You can choose all event series, the
         ones you are subscribed to, or make up your own selection. If you opt for your own
@@ -2372,7 +2373,7 @@ en:
       type: >
         Select one, several, or all of the following media types: <i>lesson</i>, <i>worked example</i>,
         <i>exercise</i>, <i>manuscript</i>, <i>repetition</i>, <i>quiz</i>, and <i>miscellaneous</i>.
-        The operator used is the inclusive <i>OR</i>. 
+        The operator used is the inclusive <i>OR</i>.
     tag_title: >
       enter at least 2 letters (or leave free for all tags)
   errors:
diff --git a/config/routes.rb b/config/routes.rb
index 964976b33..c2fb0e3ec 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -775,10 +775,6 @@
       to: 'users#fill_user_select',
       as: 'fill_user_select'
 
-  get 'users/list',
-      to: 'users#list',
-      as: 'list_users'
-
   get 'users/delete_account',
       to: 'users#delete_account',
       as: 'delete_account'
@@ -859,7 +855,7 @@
     authenticated :user do
       root to: 'main#start'
     end
-	
+
     unauthenticated do
       root to: 'devise/sessions#new', as: :unauthenticated_root
     end

From a0befa07529eeea49a8db9b109c5226dd79cffb4 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Mon, 10 Apr 2023 14:20:44 +0200
Subject: [PATCH 02/22] fix typos

---
 app/abilities/user_ability.rb | 2 +-
 app/models/user.rb            | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/abilities/user_ability.rb b/app/abilities/user_ability.rb
index 506fcb944..ab68f67ef 100644
--- a/app/abilities/user_ability.rb
+++ b/app/abilities/user_ability.rb
@@ -15,7 +15,7 @@ def initialize(user)
     end
 
     can :fill_user_select, User do
-      !user.can_edit_teachables?
+      user.can_edit_teachables?
     end
 
     can :list_generic_users, User do
diff --git a/app/models/user.rb b/app/models/user.rb
index c29d88f44..74b3d49c8 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -308,7 +308,7 @@ def can_edit_teachables?
   # a user is an editor iff he/she is a course editor or lecture editor or
   # editor of media that are not associated to talks
   def editor?
-    teachable_editor ||
+    teachable_editor? ||
       edited_media.where.not(teachable_type: 'Talk').any?
   end
 

From 5e11404064714c3b3233d496615457f268a89ce4 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Sun, 23 Apr 2023 16:42:55 +0200
Subject: [PATCH 03/22] restrict access for editors of old lectures

---
 app/abilities/lecture_ability.rb            |   2 +-
 app/abilities/user_ability.rb               |   2 +-
 app/controllers/media_controller.rb         |   2 +-
 app/models/user.rb                          |  23 +++
 app/views/lectures/edit/_people.html.erb    | 175 ++++++++++----------
 app/views/lectures/edit/_tutorials.html.erb |  71 ++++----
 config/locales/de.yml                       |   5 +
 config/locales/en.yml                       |   5 +
 8 files changed, 165 insertions(+), 120 deletions(-)

diff --git a/app/abilities/lecture_ability.rb b/app/abilities/lecture_ability.rb
index c465cd87d..76fd3ddbb 100644
--- a/app/abilities/lecture_ability.rb
+++ b/app/abilities/lecture_ability.rb
@@ -33,7 +33,7 @@ def initialize(user)
     end
 
     can :subscribe_page, Lecture do |lecture|
-      lecture.published? || user.can_edit_teachables?
+      lecture.published? || user.active_teachable_editor?
     end
   end
 end
\ No newline at end of file
diff --git a/app/abilities/user_ability.rb b/app/abilities/user_ability.rb
index ab68f67ef..78b35270d 100644
--- a/app/abilities/user_ability.rb
+++ b/app/abilities/user_ability.rb
@@ -15,7 +15,7 @@ def initialize(user)
     end
 
     can :fill_user_select, User do
-      user.can_edit_teachables?
+      user.active_teachable_editor?
     end
 
     can :list_generic_users, User do
diff --git a/app/controllers/media_controller.rb b/app/controllers/media_controller.rb
index a3dbe1560..7602c6f06 100644
--- a/app/controllers/media_controller.rb
+++ b/app/controllers/media_controller.rb
@@ -213,7 +213,7 @@ def search
     authorize! :search, Medium.new
 
     # get all media, then set them to only those that are visible to the current user
-    if !current_user.can_edit_teachables? || search_params[:access].blank?
+    if !current_user.active_teachable_editor? || search_params[:access].blank?
       filter_media = true
       params["search"]["access"] = 'irrelevant'
     end
diff --git a/app/models/user.rb b/app/models/user.rb
index 74b3d49c8..eefc44b38 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -305,6 +305,18 @@ def can_edit_teachables?
     admin? || teachable_editor_or_teacher?
   end
 
+  # if you are not a teacher of lecture or a module editor,
+  # but just an additional editor of some lecture, you
+  # will not be considered active if all of your edited lectures
+  # are older than one year
+  def active_teachable_editor?
+    return false unless can_edit_teachables?
+    return true if admin || course_editor? || teacher?
+
+    edited_lectures.select { |l| l.term.nil? || !l.older_than?(1.year)}
+                   .any?
+  end
+
   # a user is an editor iff he/she is a course editor or lecture editor or
   # editor of media that are not associated to talks
   def editor?
@@ -703,6 +715,17 @@ def generic?
     !(admin? || teacher? || editor?)
   end
 
+  # for lectures that are older than one year, only the teacher or an editor
+  # of the course it belongs to can view users in forms related to the lecture
+  def can_view_users?(lecture)
+    return false unless can_edit?(lecture)
+    return true if can_edit?(lecture.course) || lecture.teacher == self
+    return true if lecture.course.term_independent
+    return true if !lecture.older_than?(1.year)
+
+    false
+  end
+
   private
 
   def set_defaults
diff --git a/app/views/lectures/edit/_people.html.erb b/app/views/lectures/edit/_people.html.erb
index fb1b53472..1ad86cbc1 100644
--- a/app/views/lectures/edit/_people.html.erb
+++ b/app/views/lectures/edit/_people.html.erb
@@ -19,97 +19,104 @@
          aria-labelledby="heading"
          data-parent="#lectureAccordion">
       <div class="card-body">
-        <%= form_with model: lecture, html: { id: 'lecture-form' } do |f| %>
-          <div class="form-row">
-            <div class="col-4 form-group">
-              <%= f.label :teacher_id,
-                          t('basics.teacher') %>
-              <%= helpdesk(t('admin.lecture.info.teacher'), false) %>
-              <div id="lecture_teacher_select" %>
-                <%= f.select :teacher_id,
-                             options_for_select([[lecture.teacher.info,
-                                                  lecture.teacher.id]],
-                                                  lecture.teacher.id),
-                             {},
-                             { class: 'selectize',
-                               data: { ajax: true,
-                                       model: 'user',
-                                       filled: false,
-                                       placeholder: t('basics.enter_two_letters'),
-                                       no_results: t('basics.no_results') } } %>
-                <div class="invalid-feedback" id="lecture-teacher-error">
+        <% if current_user.can_view_users?(lecture) %>
+          <%= form_with model: lecture, html: { id: 'lecture-form' } do |f| %>
+            <div class="form-row">
+              <div class="col-4 form-group">
+                <%= f.label :teacher_id,
+                            t('basics.teacher') %>
+                <%= helpdesk(t('admin.lecture.info.teacher'), false) %>
+                <div id="lecture_teacher_select" %>
+                  <%= f.select :teacher_id,
+                               options_for_select([[lecture.teacher.info,
+                                                    lecture.teacher.id]],
+                                                    lecture.teacher.id),
+                               {},
+                               { class: 'selectize',
+                                 data: { ajax: true,
+                                         model: 'user',
+                                         filled: false,
+                                         placeholder:
+                                           t('basics.enter_two_letters'),
+                                         no_results:
+                                           t('basics.no_results') } } %>
+                  <div class="invalid-feedback" id="lecture-teacher-error">
+                  </div>
                 </div>
               </div>
-            </div>
-            <div class="col-4">
-              <%= t('basics.course_editors') %>
-              <%= helpdesk(t('admin.lecture.info.course_editors'), false) %>
-              <% if lecture.course.editors.present? %>
-                <ul>
-                  <% lecture.course.editors.each do |e| %>
-                    <li>
-                      <%= e.name %>
-                    </li>
-                  <% end %>
-                </ul>
-              <% else %>
-                <br>
-                <%= t('admin.lecture.no_course_editors') %>
-              <% end %>
-            </div>
-            <div class="col-4 form-group">
-              <%= f.label :editor_ids,
-                          t('basics.lecture_editors') %>
-              <%= helpdesk(t('admin.lecture.info.lecture_editors'), false) %>
-              <div id="lecture_editors_select" %>
-                <%= f.select :editor_ids,
-                             options_for_select([[t('none'), '']] +
-                                                lecture.select_editors,
-                                                lecture.editors.map(&:id)),
-                             {},
-                             { multiple: true,
-                               class: 'selectize',
-                               data: { ajax: true,
-                                       model: 'user',
-                                       filled: false,
-                                       placeholder: t('basics.enter_two_letters'),
-                                       no_results: t('basics.no_results') } } %>
+              <div class="col-4">
+                <%= t('basics.course_editors') %>
+                <%= helpdesk(t('admin.lecture.info.course_editors'), false) %>
+                <% if lecture.course.editors.present? %>
+                  <ul>
+                    <% lecture.course.editors.each do |e| %>
+                      <li>
+                        <%= e.name %>
+                      </li>
+                    <% end %>
+                  </ul>
+                <% else %>
+                  <br>
+                  <%= t('admin.lecture.no_course_editors') %>
+                <% end %>
+              </div>
+              <div class="col-4 form-group">
+                <%= f.label :editor_ids,
+                            t('basics.lecture_editors') %>
+                <%= helpdesk(t('admin.lecture.info.lecture_editors'), false) %>
+                <div id="lecture_editors_select" %>
+                  <%= f.select :editor_ids,
+                               options_for_select([[t('none'), '']] +
+                                                  lecture.select_editors,
+                                                  lecture.editors.map(&:id)),
+                               {},
+                               { multiple: true,
+                                 class: 'selectize',
+                                 data: { ajax: true,
+                                         model: 'user',
+                                         filled: false,
+                                         placeholder: t('basics.enter_two_letters'),
+                                         no_results: t('basics.no_results') } } %>
+                </div>
               </div>
             </div>
-          </div>
-          <div class="row mb-3">
-            <div class="col-12">
-              <%= t('basics.subscribers_count_nc') %>
-              <span id="lectureUserCounter">
-                <%= lecture.users.count %>
-              </span>
-              <%= helpdesk(t('admin.lecture.info.subscribers_count'), false) %>
-              <% if lecture.users.any? && !lecture.older_than?(1.year)%>
-                <button type="button"
-                        id="lectureUserModalButton"
-                        class="ml-3 btn btn-outline-primary btn-sm"
-                        data-toggle="modal"
-                        data-target="#lectureUserModal">
-                  <%= t('basics.details') %>
-                </button>
-              <% end %>
+            <div class="row mb-3">
+              <div class="col-12">
+                <%= t('basics.subscribers_count_nc') %>
+                <span id="lectureUserCounter">
+                  <%= lecture.users.count %>
+                </span>
+                <%= helpdesk(t('admin.lecture.info.subscribers_count'), false) %>
+                <% if lecture.users.any? && !lecture.older_than?(1.year)%>
+                  <button type="button"
+                          id="lectureUserModalButton"
+                          class="ml-3 btn btn-outline-primary btn-sm"
+                          data-toggle="modal"
+                          data-target="#lectureUserModal">
+                    <%= t('basics.details') %>
+                  </button>
+                <% end %>
+              </div>
             </div>
-          </div>
-          <div class="row mt-3">
-            <div class="col-12 text-center">
-              <div id="lecture-basics-warning">
-                <%= t('warnings.unsaved_changes') %>
-                <%= f.submit t('buttons.save'),
-                    class: "btn btn-sm btn-primary" %>
-                <button type="button"
-                        class="btn btn-sm btn-secondary ml-2"
-                        id="lecture-basics-cancel"
-                        data-id="<%= lecture.id %>">
-                  <%= t('buttons.discard') %>
-                </button>
+            <div class="row mt-3">
+              <div class="col-12 text-center">
+                <div id="lecture-basics-warning">
+                  <%= t('warnings.unsaved_changes') %>
+                  <%= f.submit t('buttons.save'),
+                      class: "btn btn-sm btn-primary" %>
+                  <button type="button"
+                          class="btn btn-sm btn-secondary ml-2"
+                          id="lecture-basics-cancel"
+                          data-id="<%= lecture.id %>">
+                    <%= t('buttons.discard') %>
+                  </button>
+                </div>
               </div>
             </div>
-          </div>
+          <% end %>
+        <% else %>
+          <%= t('admin.lecture.no_access_to_users_html',
+                project_mail: mail_to(DefaultSetting::PROJECT_EMAIL, nil)) %>
         <% end %>
       </div>
     </div>
diff --git a/app/views/lectures/edit/_tutorials.html.erb b/app/views/lectures/edit/_tutorials.html.erb
index 0d889d08f..0bb1d50a3 100644
--- a/app/views/lectures/edit/_tutorials.html.erb
+++ b/app/views/lectures/edit/_tutorials.html.erb
@@ -19,43 +19,48 @@
        aria-labelledby="heading"
        data-parent="#lectureAccordion">
     <div class="card-body">
-      <div class="row mb-3">
-        <div class="col-12 text-center">
-          <%= link_to t('admin.tutorial.new'),
-                      new_tutorial_path(params: { lecture_id: lecture.id }),
-                      class: 'btn btn-sm btn-primary',
-                      id: 'newTutorialButton',
-                      remote: true %>
+      <% if current_user.can_view_users?(lecture) %>
+        <div class="row mb-3">
+          <div class="col-12 text-center">
+            <%= link_to t('admin.tutorial.new'),
+                        new_tutorial_path(params: { lecture_id: lecture.id }),
+                        class: 'btn btn-sm btn-primary',
+                        id: 'newTutorialButton',
+                        remote: true %>
+          </div>
         </div>
-      </div>
-      <div class="list-group">
-        <div class="list-group-item bg-light"
-             id="tutorialListHeader"
-             style="display: <%= show(lecture.tutorials.any?) %>">
-          <div class="row">
-            <div class="col-4">
-              <h6>
-                <%= t('basics.title') %>
-              </h6>
-            </div>
-            <div class="col-4">
-              <h6>
-                <%= t('basics.tutors') %>
-              </h6>
-            </div>
-            <div class="col-4">
-              <h6>
-                <%= t('basics.action') %>
-                <%= helpdesk(t('tutorial.destruction_info'), true) %>
-              </h6>
+        <div class="list-group">
+          <div class="list-group-item bg-light"
+               id="tutorialListHeader"
+               style="display: <%= show(lecture.tutorials.any?) %>">
+            <div class="row">
+              <div class="col-4">
+                <h6>
+                  <%= t('basics.title') %>
+                </h6>
+              </div>
+              <div class="col-4">
+                <h6>
+                  <%= t('basics.tutors') %>
+                </h6>
+              </div>
+              <div class="col-4">
+                <h6>
+                  <%= t('basics.action') %>
+                  <%= helpdesk(t('tutorial.destruction_info'), true) %>
+                </h6>
+              </div>
             </div>
           </div>
+          <% lecture.tutorials.each do |t| %>
+            <%= render partial: 'tutorials/row',
+                       locals: { tutorial: t } %>
+          <% end %>
         </div>
-        <% lecture.tutorials.each do |t| %>
-          <%= render partial: 'tutorials/row',
-                     locals: { tutorial: t } %>
-        <% end %>
-      </div>
+      <% else %>
+          <%= t('admin.lecture.no_access_to_users_html',
+                project_mail: mail_to(DefaultSetting::PROJECT_EMAIL, nil)) %>
+      <% end %>
     </div>
   </div>
 </div>
\ No newline at end of file
diff --git a/config/locales/de.yml b/config/locales/de.yml
index b94370128..88c0d4694 100644
--- a/config/locales/de.yml
+++ b/config/locales/de.yml
@@ -650,6 +650,11 @@ de:
       insert_after_chapter: 'Einfügen nach %{chapter_name}'
       insert_after_section: 'Einfügen nach Abschnitt'
       subscribers: 'AbonnentInnen'
+      no_access_to_users_html: >
+        Diese Vorlesung ist älter als ein Jahr. Aus Datenschutzgründen können
+        nur die DozentIn und ModuleditorInnen an dieser Stelle Änderungen
+        vornehmen. Sollten aus wichtigem Grund noch Änderungen an dieser Stelle
+        gemacht werden, kannst Du Dich per Email an %{project_mail} wenden.
     clicker:
       new_clicker: 'Neuen Clicker anlegen'
       user_link: 'Link für NutzerInnen'
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 04cde8f4a..188842953 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -620,6 +620,11 @@ en:
       insert_after_chapter: 'Insert after %{chapter_name}'
       insert_after_section: 'Insert after section'
       subscribers: 'Subscribers'
+      no_access_to_users_html: >
+        This lecture is older than 1 year. For reasons of data privacy,
+        only the teahcer and course editors can make changes here.
+        If changes are necessary for some reason, you can contact the
+        site administrators by mail: %{project_mail}.
     clicker:
       new_clicker: 'Create new Clicker'
       user_link: 'Link for users'

From ace66cbdde5de145034067d5dc73a9783641b78c Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Sat, 29 Apr 2023 01:22:36 +0200
Subject: [PATCH 04/22] make some changes suggested by referee

---
 app/models/lecture.rb                    | 4 ++++
 app/models/user.rb                       | 6 +++---
 app/views/lectures/edit/_form.html.erb   | 2 +-
 app/views/lectures/edit/_people.html.erb | 2 +-
 config/locales/de.yml                    | 2 +-
 config/locales/en.yml                    | 6 +++---
 6 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/app/models/lecture.rb b/app/models/lecture.rb
index b1d288c23..e368dc42f 100644
--- a/app/models/lecture.rb
+++ b/app/models/lecture.rb
@@ -781,6 +781,10 @@ def older_than?(timespan)
     term.begin_date < Term.active.begin_date - timespan
   end
 
+  def stale?
+    older_than?(1.year)
+  end
+
   private
 
   # used for after save callback
diff --git a/app/models/user.rb b/app/models/user.rb
index eefc44b38..79ca5543d 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -313,7 +313,7 @@ def active_teachable_editor?
     return false unless can_edit_teachables?
     return true if admin || course_editor? || teacher?
 
-    edited_lectures.select { |l| l.term.nil? || !l.older_than?(1.year)}
+    edited_lectures.select { |l| l.term.nil? || !stale? }
                    .any?
   end
 
@@ -721,9 +721,9 @@ def can_view_users?(lecture)
     return false unless can_edit?(lecture)
     return true if can_edit?(lecture.course) || lecture.teacher == self
     return true if lecture.course.term_independent
-    return true if !lecture.older_than?(1.year)
+    return true if !lecture.stale?
 
-    false
+    return false
   end
 
   private
diff --git a/app/views/lectures/edit/_form.html.erb b/app/views/lectures/edit/_form.html.erb
index 1502ac284..cd5a50857 100644
--- a/app/views/lectures/edit/_form.html.erb
+++ b/app/views/lectures/edit/_form.html.erb
@@ -54,7 +54,7 @@
   <%= render partial: 'announcements/modal' %>
   <%= render partial: 'lectures/publish/publish',
              locals: { lecture: lecture } %>
-  <% unless lecture.older_than?(1.year) %>
+  <% unless lecture.stale? %>
     <%= render partial: 'lectures/edit/user_modal',
                locals: { lecture: lecture } %>
   <% end %>
diff --git a/app/views/lectures/edit/_people.html.erb b/app/views/lectures/edit/_people.html.erb
index 1ad86cbc1..0435b8383 100644
--- a/app/views/lectures/edit/_people.html.erb
+++ b/app/views/lectures/edit/_people.html.erb
@@ -87,7 +87,7 @@
                   <%= lecture.users.count %>
                 </span>
                 <%= helpdesk(t('admin.lecture.info.subscribers_count'), false) %>
-                <% if lecture.users.any? && !lecture.older_than?(1.year)%>
+                <% if lecture.users.any? && !lecture.stale? %>
                   <button type="button"
                           id="lectureUserModalButton"
                           class="ml-3 btn btn-outline-primary btn-sm"
diff --git a/config/locales/de.yml b/config/locales/de.yml
index 61a5d6527..374df71f0 100644
--- a/config/locales/de.yml
+++ b/config/locales/de.yml
@@ -2058,7 +2058,7 @@ de:
     data_request: >
       Daten anfordern
     data_request_sent: >
-      Wir haben deine Anfrage erhalten und werden dir deine Daten zeitnah schicken.
+      Wir haben Deine Anfrage erhalten und werden Dir Deine Daten zeitnah schicken.
   mampf_news:
     title: 'MaMpf-News'
     check_notifications: 'Alle erledigen'
diff --git a/config/locales/en.yml b/config/locales/en.yml
index f1f04a542..e89d965b9 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -111,7 +111,7 @@ en:
     sponsorships: 'Projekt funding'
     hse: 'Heidelberg School of Education (HSE)'
     go_digital_html: >
-      Within the framework of the joint project %{digital_now}, MaMpf has been 
+      Within the framework of the joint project %{digital_now}, MaMpf has been
       supported by the acquisition of media technology equipment which is going
       to help with meeting the increased demand for hypermedia content.
     fellowship_html: >
@@ -620,7 +620,7 @@ en:
       subscribers: 'Subscribers'
       no_access_to_users_html: >
         This lecture is older than 1 year. For reasons of data privacy,
-        only the teahcer and course editors can make changes here.
+        only the teacher and course editors can make changes here.
         If changes are necessary for some reason, you can contact the
         site administrators by mail: %{project_mail}.
     clicker:
@@ -1086,7 +1086,7 @@ en:
           This is the list of all persons that are responsible for this
           medium as editor. At least one person has to be given here, and each
           of these persons gets editing access to this medium. Only eligible
-          persons can be selected.
+          people can be selected.
           <br>
           Note: Independently from this setting, this medium can be edited
           by people with hiher access rights, e.g. editors of the associated

From 9fefc79a1a50cca5df5ce7f9a3ae120993dd85dd Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Fri, 5 May 2023 20:32:34 +0200
Subject: [PATCH 05/22] make changes to meet referee requests

---
 app/models/lecture.rb | 2 +-
 app/models/medium.rb  | 2 +-
 app/models/user.rb    | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/app/models/lecture.rb b/app/models/lecture.rb
index e368dc42f..7678a4c02 100644
--- a/app/models/lecture.rb
+++ b/app/models/lecture.rb
@@ -778,7 +778,7 @@ def speakers
 
   def older_than?(timespan)
     return true unless term
-    term.begin_date < Term.active.begin_date - timespan
+    term.begin_date <= Term.active.begin_date - timespan
   end
 
   def stale?
diff --git a/app/models/medium.rb b/app/models/medium.rb
index af326c2b8..b4704d49e 100644
--- a/app/models/medium.rb
+++ b/app/models/medium.rb
@@ -460,7 +460,7 @@ def eligible_editors(user)
     result = editors_with_inheritance
 
     if teachable.is_a?(Talk) && user.can_edit?(lecture)
-      result += lecture.speakers
+      result.concat(lecture.speakers)
     end
 
     result << user if user.admin?
diff --git a/app/models/user.rb b/app/models/user.rb
index 79ca5543d..3d081383f 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -308,7 +308,7 @@ def can_edit_teachables?
   # if you are not a teacher of lecture or a module editor,
   # but just an additional editor of some lecture, you
   # will not be considered active if all of your edited lectures
-  # are older than one year
+  # are too old
   def active_teachable_editor?
     return false unless can_edit_teachables?
     return true if admin || course_editor? || teacher?
@@ -715,7 +715,7 @@ def generic?
     !(admin? || teacher? || editor?)
   end
 
-  # for lectures that are older than one year, only the teacher or an editor
+  # for lectures that are too old, only the teacher or an editor
   # of the course it belongs to can view users in forms related to the lecture
   def can_view_users?(lecture)
     return false unless can_edit?(lecture)

From 1fda243d4dd25ee409d6d13d77d24701bea69843 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Sat, 6 May 2023 11:02:22 +0200
Subject: [PATCH 06/22] improve comments on editor methods

---
 app/models/user.rb | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/app/models/user.rb b/app/models/user.rb
index 3d081383f..b19831f8d 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -293,6 +293,8 @@ def teacher?
     given_lectures.any?
   end
 
+  # a user is a teachable editor iff he/she is a course editor or lecture
+  # editor
   def teachable_editor?
     edited_courses.any? || edited_lectures.any?
   end
@@ -317,7 +319,7 @@ def active_teachable_editor?
                    .any?
   end
 
-  # a user is an editor iff he/she is a course editor or lecture editor or
+  # a user is an editor iff he/she is a teachable editor or an
   # editor of media that are not associated to talks
   def editor?
     teachable_editor? ||

From f4baf2b820ebbfc51893845c97d1edd72c6b182f Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Sat, 6 May 2023 11:22:50 +0200
Subject: [PATCH 07/22] restore missing view

---
 app/views/users/list.json.jbuilder | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 app/views/users/list.json.jbuilder

diff --git a/app/views/users/list.json.jbuilder b/app/views/users/list.json.jbuilder
new file mode 100644
index 000000000..87cfb45e1
--- /dev/null
+++ b/app/views/users/list.json.jbuilder
@@ -0,0 +1,4 @@
+json.array! @users do |user|
+  json.id user.id
+  json.text user.tutorial_info
+end
\ No newline at end of file

From 6e28d5df8cb6e288d4964a7f0625a0fb34cc113d Mon Sep 17 00:00:00 2001
From: Splines <dominic-plein@gmx.de>
Date: Sun, 7 May 2023 01:19:06 +0200
Subject: [PATCH 08/22] Fix stale? method not found

---
 app/models/user.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/models/user.rb b/app/models/user.rb
index b19831f8d..14885c183 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -315,7 +315,7 @@ def active_teachable_editor?
     return false unless can_edit_teachables?
     return true if admin || course_editor? || teacher?
 
-    edited_lectures.select { |l| l.term.nil? || !stale? }
+    edited_lectures.select { |l| l.term.nil? || !l.stale? }
                    .any?
   end
 

From 7f751a28e87a414dd8431d7538663709b2e4ed6f Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Sun, 7 May 2023 10:54:53 +0200
Subject: [PATCH 09/22] restrict routes for stale editors

---
 app/abilities/tutorial_ability.rb           |  2 +-
 app/controllers/lectures_controller.rb      | 23 ++++++++++-----------
 app/models/user.rb                          |  4 ++--
 app/views/lectures/edit/_people.html.erb    |  2 +-
 app/views/lectures/edit/_tutorials.html.erb |  2 +-
 5 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/app/abilities/tutorial_ability.rb b/app/abilities/tutorial_ability.rb
index 260a09b40..9b1629226 100644
--- a/app/abilities/tutorial_ability.rb
+++ b/app/abilities/tutorial_ability.rb
@@ -6,7 +6,7 @@ def initialize(user)
 
     can [:new, :create, :edit, :update, :destroy, :cancel_edit,
          :cancel_new], Tutorial do |tutorial|
-      user.can_edit?(tutorial.lecture)
+      user.can_update_personell?(tutorial.lecture)
     end
 
     can :overview, Tutorial do |tutorial, lecture|
diff --git a/app/controllers/lectures_controller.rb b/app/controllers/lectures_controller.rb
index bf7a63ffb..b9d0f4a80 100644
--- a/app/controllers/lectures_controller.rb
+++ b/app/controllers/lectures_controller.rb
@@ -44,7 +44,7 @@ def update
                           .new_editor_email.deliver_later
       end
     end
-    
+
     @lecture.update(lecture_params)
     if structure_params.present?
       structure_ids = structure_params.select { |_k, v| v.to_i == 1 }.keys
@@ -300,17 +300,16 @@ def check_for_subscribe
   end
 
   def lecture_params
-    params.require(:lecture).permit(:course_id, :term_id, :teacher_id,
-                                    :start_chapter, :absolute_numbering,
-                                    :start_section, :organizational, :locale,
-                                    :organizational_concept, :muesli,
-                                    :organizational_on_top,
-                                    :disable_teacher_display,
-                                    :content_mode, :passphrase, :sort,
-                                    :comments_disabled,
-                                    :submission_max_team_size,
-                                    :submission_grace_period,
-                                    editor_ids: [])
+    allowed_params = [:term_id, :start_chapter, :absolute_numbering,
+                      :start_section, :organizational, :locale,
+                      :organizational_concept, :muesli, :organizational_on_top,
+                      :disable_teacher_display, :content_mode, :passphrase,
+                      :sort, :comments_disabled, :submission_max_team_size,
+                      :submission_grace_period]
+    if current_user.can_update_personell?(@lecture)
+      allowed_params.concat([:teacher_id, editor_ids: []])
+    end
+    params.require(:lecture).permit(allowed_params)
   end
 
   def structure_params
diff --git a/app/models/user.rb b/app/models/user.rb
index b19831f8d..d12973670 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -718,8 +718,8 @@ def generic?
   end
 
   # for lectures that are too old, only the teacher or an editor
-  # of the course it belongs to can view users in forms related to the lecture
-  def can_view_users?(lecture)
+  # of the course it belongs to can update the personell of to the lecture
+  def can_update_personell?(lecture)
     return false unless can_edit?(lecture)
     return true if can_edit?(lecture.course) || lecture.teacher == self
     return true if lecture.course.term_independent
diff --git a/app/views/lectures/edit/_people.html.erb b/app/views/lectures/edit/_people.html.erb
index 0435b8383..ca26c5131 100644
--- a/app/views/lectures/edit/_people.html.erb
+++ b/app/views/lectures/edit/_people.html.erb
@@ -19,7 +19,7 @@
          aria-labelledby="heading"
          data-parent="#lectureAccordion">
       <div class="card-body">
-        <% if current_user.can_view_users?(lecture) %>
+        <% if current_user.can_update_personell?(lecture) %>
           <%= form_with model: lecture, html: { id: 'lecture-form' } do |f| %>
             <div class="form-row">
               <div class="col-4 form-group">
diff --git a/app/views/lectures/edit/_tutorials.html.erb b/app/views/lectures/edit/_tutorials.html.erb
index 0bb1d50a3..e6f81bb0e 100644
--- a/app/views/lectures/edit/_tutorials.html.erb
+++ b/app/views/lectures/edit/_tutorials.html.erb
@@ -19,7 +19,7 @@
        aria-labelledby="heading"
        data-parent="#lectureAccordion">
     <div class="card-body">
-      <% if current_user.can_view_users?(lecture) %>
+      <% if current_user.can_update_personell?(lecture) %>
         <div class="row mb-3">
           <div class="col-12 text-center">
             <%= link_to t('admin.tutorial.new'),

From 4abf4bd0cbf6cc6a3e65188d5c639f6900720573 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Sun, 7 May 2023 11:16:47 +0200
Subject: [PATCH 10/22] fix broken create lecture action

---
 app/controllers/lectures_controller.rb | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/app/controllers/lectures_controller.rb b/app/controllers/lectures_controller.rb
index b9d0f4a80..3ef5b2d08 100644
--- a/app/controllers/lectures_controller.rb
+++ b/app/controllers/lectures_controller.rb
@@ -306,9 +306,12 @@ def lecture_params
                       :disable_teacher_display, :content_mode, :passphrase,
                       :sort, :comments_disabled, :submission_max_team_size,
                       :submission_grace_period]
-    if current_user.can_update_personell?(@lecture)
+    if action_name == 'update' && current_user.can_update_personell?(@lecture)
       allowed_params.concat([:teacher_id, editor_ids: []])
     end
+    if action_name == 'create'
+      allowed_params.concat([:course_id, :teacher_id, editor_ids: []])
+    end
     params.require(:lecture).permit(allowed_params)
   end
 

From d00d5af03b3f76a641ecf2c71c24f2564844506e Mon Sep 17 00:00:00 2001
From: Splines <37160523+Splines@users.noreply.github.com>
Date: Thu, 11 May 2023 17:04:49 +0200
Subject: [PATCH 11/22] Update rubocop version (#494)

* Update rubocop version

The old version does not work with the Ruby LSP VS Code extension.

* Exclude some rubocop metrics (for now)

* Reflect rubocop version update in lockfile
---
 .rubocop.yml | 19 ++++++++++++++++++-
 Gemfile      |  2 +-
 Gemfile.lock | 22 ++++++++++++----------
 3 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/.rubocop.yml b/.rubocop.yml
index b3cc9d86d..d7b548944 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -201,6 +201,9 @@ Style/RedundantFreeze:
 Style/SymbolProc:
   Enabled: true
 
+Style/SymbolArray:
+  Enabled: false
+
 # Use `foo {}` not `foo{}`.
 Layout/SpaceBeforeBlockBraces:
   Enabled: true
@@ -321,4 +324,18 @@ Performance/DeletePrefix:
   Enabled: true
 
 Performance/DeleteSuffix:
-  Enabled: true
\ No newline at end of file
+  Enabled: true
+
+Metrics/ModuleLength:
+  Enabled: false
+
+Metrics/ClassLength:
+  Enabled: false
+
+Metrics/MethodLength:
+  Exclude:
+    - 'app/abilities/**/*'
+
+Metrics/AbcSize:
+  Exclude:
+    - 'app/abilities/**/*'
\ No newline at end of file
diff --git a/Gemfile b/Gemfile
index c97d4a8eb..d24e6e02c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -120,7 +120,7 @@ group :development, :docker_development do
   # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
   gem "spring"
   gem "spring-watcher-listen", "~> 2.0.0"
-  gem "rubocop", "~> 0.93", require: false
+  gem "rubocop", "~> 1.50", require: false
   gem "rubocop-packaging", require: false
   gem "rubocop-performance", require: false
   gem "rubocop-rails", require: false
diff --git a/Gemfile.lock b/Gemfile.lock
index dd090e8af..5f8fb5465 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -304,6 +304,7 @@ GEM
     js-routes (1.4.9)
       railties (>= 4)
       sprockets-rails
+    json (2.6.3)
     jsonapi-renderer (0.2.2)
     kaminari (1.2.2)
       activesupport (>= 4.1.0)
@@ -377,7 +378,7 @@ GEM
     options (2.3.2)
     orm_adapter (0.5.0)
     pairing_heap (3.0.0)
-    parallel (1.22.1)
+    parallel (1.23.0)
     parser (3.2.2.0)
       ast (~> 2.4.1)
     pdf-reader (2.11.0)
@@ -458,7 +459,7 @@ GEM
       ffi (~> 1.0)
     redis-client (0.14.1)
       connection_pool
-    regexp_parser (2.7.0)
+    regexp_parser (2.8.0)
     request_store (1.5.1)
       rack (>= 1.4)
     responders (3.1.0)
@@ -499,15 +500,16 @@ GEM
       rspec-mocks (~> 3.11)
       rspec-support (~> 3.11)
     rspec-support (3.12.0)
-    rubocop (0.93.1)
+    rubocop (1.50.2)
+      json (~> 2.3)
       parallel (~> 1.10)
-      parser (>= 2.7.1.5)
+      parser (>= 3.2.0.0)
       rainbow (>= 2.2.2, < 4.0)
-      regexp_parser (>= 1.8)
-      rexml
-      rubocop-ast (>= 0.6.0)
+      regexp_parser (>= 1.8, < 3.0)
+      rexml (>= 3.2.5, < 4.0)
+      rubocop-ast (>= 1.28.0, < 2.0)
       ruby-progressbar (~> 1.7)
-      unicode-display_width (>= 1.4.0, < 2.0)
+      unicode-display_width (>= 2.4.0, < 3.0)
     rubocop-ast (1.28.0)
       parser (>= 3.2.1.0)
     rubocop-packaging (0.5.1)
@@ -629,7 +631,7 @@ GEM
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.8.2)
-    unicode-display_width (1.8.0)
+    unicode-display_width (2.4.2)
     warden (1.2.9)
       rack (>= 2.0.9)
     web-console (4.2.0)
@@ -718,7 +720,7 @@ DEPENDENCIES
   rgl
   rqrcode
   rspec-rails
-  rubocop (~> 0.93)
+  rubocop (~> 1.50)
   rubocop-packaging
   rubocop-performance
   rubocop-rails

From 5f7c956e60994bca9f965511e491fadac788344e Mon Sep 17 00:00:00 2001
From: Splines <37160523+Splines@users.noreply.github.com>
Date: Thu, 11 May 2023 17:05:39 +0200
Subject: [PATCH 12/22] Enforce rubocop layout rules (#495)

* Update rubocop version

The old version does not work with the Ruby LSP VS Code extension.

* Exclude some rubocop metrics (for now)

* Enforce rubocop layout rules
---
 app/abilities/administration_ability.rb       |   2 +-
 app/abilities/announcement_ability.rb         |   4 +-
 app/abilities/answer_ability.rb               |   2 +-
 app/abilities/assignment_ability.rb           |   2 +-
 app/abilities/chapter_ability.rb              |   2 +-
 app/abilities/course_ability.rb               |   2 +-
 app/abilities/division_ability.rb             |   2 +-
 app/abilities/erdbeere_ability.rb             |   2 +-
 app/abilities/interaction_ability.rb          |   2 +-
 app/abilities/item_ability.rb                 |   4 +-
 app/abilities/lecture_ability.rb              |   2 +-
 app/abilities/lesson_ability.rb               |   2 +-
 app/abilities/main_ability.rb                 |   2 +-
 app/abilities/medium_ability.rb               |   8 +-
 app/abilities/notification_ability.rb         |   2 +-
 app/abilities/profile_ability.rb              |   2 +-
 app/abilities/program_ability.rb              |   2 +-
 app/abilities/question_ability.rb             |   2 +-
 app/abilities/quiz_ability.rb                 |   2 +-
 app/abilities/quiz_certificate_ability.rb     |   2 +-
 app/abilities/referral_ability.rb             |   2 +-
 app/abilities/remark_ability.rb               |   2 +-
 app/abilities/search_ability.rb               |   2 +-
 app/abilities/section_ability.rb              |   2 +-
 app/abilities/subject_ability.rb              |   2 +-
 app/abilities/submission_ability.rb           |   6 +-
 app/abilities/tag_ability.rb                  |   1 -
 app/abilities/term_ability.rb                 |   2 +-
 app/abilities/tutorial_ability.rb             |   6 +-
 app/abilities/watchlist_ability.rb            |   2 +-
 app/controllers/announcements_controller.rb   |  79 ++--
 app/controllers/answers_controller.rb         |  19 +-
 app/controllers/application_controller.rb     | 110 ++---
 app/controllers/assignments_controller.rb     |  43 +-
 app/controllers/chapters_controller.rb        |  31 +-
 app/controllers/clicker_votes_controller.rb   |   6 +-
 app/controllers/clickers_controller.rb        |  31 +-
 app/controllers/confirmations_controller.rb   |  11 +-
 app/controllers/courses_controller.rb         | 113 ++---
 app/controllers/divisions_controller.rb       |  56 +--
 app/controllers/erdbeere_controller.rb        |  92 ++--
 app/controllers/interactions_controller.rb    |  32 +-
 app/controllers/items_controller.rb           |  39 +-
 app/controllers/lectures_controller.rb        | 272 +++++------
 app/controllers/lessons_controller.rb         |  45 +-
 app/controllers/main_controller.rb            |  16 +-
 app/controllers/media_controller.rb           | 441 +++++++++---------
 app/controllers/notifications_controller.rb   |  12 +-
 app/controllers/profile_controller.rb         | 160 ++++---
 app/controllers/programs_controller.rb        |  57 ++-
 app/controllers/questions_controller.rb       |  71 +--
 .../quiz_certificates_controller.rb           |  48 +-
 app/controllers/quizzes_controller.rb         | 105 +++--
 app/controllers/readers_controller.rb         |   9 +-
 app/controllers/referrals_controller.rb       |  69 +--
 app/controllers/registrations_controller.rb   |  41 +-
 app/controllers/remarks_controller.rb         |  25 +-
 app/controllers/search_controller.rb          |  42 +-
 app/controllers/sections_controller.rb        |  70 +--
 app/controllers/sessions_controller.rb        |   3 +-
 app/controllers/subjects_controller.rb        |  30 +-
 app/controllers/submissions_controller.rb     | 399 ++++++++--------
 app/controllers/tags_controller.rb            | 298 ++++++------
 app/controllers/terms_controller.rb           |  25 +-
 app/controllers/tutorials_controller.rb       | 131 +++---
 app/controllers/users_controller.rb           |  37 +-
 app/controllers/vertices_controller.rb        |  83 ++--
 .../watchlist_entries_controller.rb           |   1 -
 app/controllers/watchlists_controller.rb      |   8 +-
 app/helpers/announcements_helper.rb           |   2 +
 app/helpers/application_helper.rb             |  50 +-
 app/helpers/assignments_helper.rb             |   3 +
 app/helpers/chapters_helper.rb                |   2 +-
 app/helpers/clickers_helper.rb                |   2 +-
 app/helpers/courses_helper.rb                 |   2 +-
 app/helpers/items_helper.rb                   |   1 +
 app/helpers/lectures_helper.rb                |  18 +-
 app/helpers/lessons_helper.rb                 |   1 +
 app/helpers/media_helper.rb                   |  15 +-
 app/helpers/notifications_helper.rb           |  53 ++-
 app/helpers/referrals_helper.rb               |   7 +-
 app/helpers/search_helper.rb                  |   4 +-
 app/helpers/submissions_helper.rb             |  62 ++-
 app/helpers/talks_helper.rb                   |   5 +-
 app/helpers/tutorials_helper.rb               |   4 +-
 app/helpers/vertices_helper.rb                |   2 +-
 app/mailers/application_mailer.rb             |   4 +-
 .../exception_handler/exception_mailer.rb     |   3 +-
 app/mailers/mathi_mailer.rb                   |   4 +-
 app/mailers/my_mailer.rb                      |   4 +-
 app/mailers/notification_mailer.rb            |  55 ++-
 app/models/ability.rb                         |   2 +-
 app/models/announcement.rb                    |   2 +-
 app/models/answer.rb                          |  33 +-
 app/models/assignment.rb                      |  28 +-
 app/models/chapter.rb                         |   5 +-
 app/models/clicker.rb                         |   9 +-
 app/models/clicker_vote.rb                    |  19 +-
 app/models/course_self_join.rb                |   8 +-
 app/models/course_tag_join.rb                 |   9 +-
 app/models/division.rb                        |  12 +-
 app/models/interaction.rb                     |  12 +-
 app/models/interactions_record.rb             |   2 +-
 app/models/item.rb                            | 328 +++++++------
 app/models/item_self_join.rb                  |  57 +--
 app/models/lecture.rb                         | 255 +++++-----
 app/models/lesson.rb                          |  76 +--
 app/models/link.rb                            |  36 +-
 app/models/mampf_expression.rb                |   2 +-
 app/models/mampf_matrix.rb                    |   5 +-
 app/models/mampf_set.rb                       |   2 +-
 app/models/mampf_tuple.rb                     |   2 +-
 app/models/manuscript.rb                      |  45 +-
 app/models/medium.rb                          | 382 +++++++++------
 app/models/medium_publisher.rb                |   1 +
 app/models/notification.rb                    |  20 +-
 app/models/notion.rb                          |   9 +-
 app/models/probe.rb                           |  15 +-
 app/models/program.rb                         |  24 +-
 app/models/question.rb                        |  20 +-
 app/models/quiz.rb                            |  19 +-
 app/models/quiz_certificate.rb                |   6 +-
 app/models/quiz_graph.rb                      |  28 +-
 app/models/quiz_round.rb                      | 103 ++--
 app/models/reader.rb                          |   4 +-
 app/models/referral.rb                        |  88 ++--
 app/models/relation.rb                        |  57 +--
 app/models/section.rb                         |  78 ++--
 app/models/section_tag_join.rb                |   2 +-
 app/models/solution.rb                        |   5 +-
 app/models/subject.rb                         |   8 +-
 app/models/submission.rb                      | 176 +++----
 app/models/submission_cleaner.rb              | 112 ++---
 app/models/tag.rb                             |  62 ++-
 app/models/talk.rb                            |   2 +-
 app/models/term.rb                            |  42 +-
 app/models/time_stamp.rb                      |  43 +-
 app/models/tutorial.rb                        |  23 +-
 app/models/user.rb                            | 172 ++++---
 app/models/user_cleaner.rb                    |  26 +-
 app/models/user_submission_join.rb            |  31 +-
 app/uploaders/correction_uploader.rb          |   2 +-
 app/uploaders/geogebra_uploader.rb            |   2 +-
 app/uploaders/pdf_uploader.rb                 |  10 +-
 app/uploaders/submission_uploader.rb          |   6 +-
 app/uploaders/video_uploader.rb               |   4 +-
 app/uploaders/vtt_uploader.rb                 |   2 +-
 app/uploaders/zip_uploader.rb                 |  16 +-
 app/validators/http_url_validator.rb          |   1 -
 app/views/users/list.json.jbuilder            |   2 +-
 app/workers/cache_cleaner.rb                  |   2 +-
 app/workers/consumption_saver.rb              |   2 +-
 app/workers/interaction_saver.rb              |   8 +-
 app/workers/media_publisher.rb                |   2 +-
 app/workers/metadata_extractor.rb             |   3 +-
 app/workers/probe_saver.rb                    |   3 +-
 app/workers/submissions_cleaner.rb            |   2 +-
 app/workers/user_cleaner_job.rb               |   2 +-
 158 files changed, 3313 insertions(+), 2803 deletions(-)

diff --git a/app/abilities/administration_ability.rb b/app/abilities/administration_ability.rb
index e1b6bb5f1..df640725d 100644
--- a/app/abilities/administration_ability.rb
+++ b/app/abilities/administration_ability.rb
@@ -12,4 +12,4 @@ def initialize(user)
       user.admin?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/announcement_ability.rb b/app/abilities/announcement_ability.rb
index ba171a55a..177f43510 100644
--- a/app/abilities/announcement_ability.rb
+++ b/app/abilities/announcement_ability.rb
@@ -14,7 +14,7 @@ def initialize(user)
 
     can :create, Announcement do |announcement|
       user.admin? ||
-      (announcement.lecture.present? && user.can_edit?(announcement.lecture))
+        (announcement.lecture.present? && user.can_edit?(announcement.lecture))
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/answer_ability.rb b/app/abilities/answer_ability.rb
index 11b610bba..f4b41b3c1 100644
--- a/app/abilities/answer_ability.rb
+++ b/app/abilities/answer_ability.rb
@@ -10,4 +10,4 @@ def initialize(user)
 
     can :update_answer_box, Answer
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/assignment_ability.rb b/app/abilities/assignment_ability.rb
index 28a85f2eb..2d39c7edd 100644
--- a/app/abilities/assignment_ability.rb
+++ b/app/abilities/assignment_ability.rb
@@ -9,4 +9,4 @@ def initialize(user)
       assignment.lecture.present? && user.can_edit?(assignment.lecture)
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/chapter_ability.rb b/app/abilities/chapter_ability.rb
index fecdd083d..2d6cb94b8 100644
--- a/app/abilities/chapter_ability.rb
+++ b/app/abilities/chapter_ability.rb
@@ -9,4 +9,4 @@ def initialize(user)
       chapter.lecture.present? && user.can_edit?(chapter.lecture)
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/course_ability.rb b/app/abilities/course_ability.rb
index ea3fba2de..5e3f1545a 100644
--- a/app/abilities/course_ability.rb
+++ b/app/abilities/course_ability.rb
@@ -20,4 +20,4 @@ def initialize(user)
       !user.generic? || course.subscribed_by?(user)
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/division_ability.rb b/app/abilities/division_ability.rb
index 0c5339168..c1a38ca88 100644
--- a/app/abilities/division_ability.rb
+++ b/app/abilities/division_ability.rb
@@ -8,4 +8,4 @@ def initialize(user)
       user.admin?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/erdbeere_ability.rb b/app/abilities/erdbeere_ability.rb
index e0ed55d84..f19f32782 100644
--- a/app/abilities/erdbeere_ability.rb
+++ b/app/abilities/erdbeere_ability.rb
@@ -12,4 +12,4 @@ def initialize(user)
       !user.generic?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/interaction_ability.rb b/app/abilities/interaction_ability.rb
index c577971ba..b8dc9f41e 100644
--- a/app/abilities/interaction_ability.rb
+++ b/app/abilities/interaction_ability.rb
@@ -8,4 +8,4 @@ def initialize(user)
       user.admin?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/item_ability.rb b/app/abilities/item_ability.rb
index 7b0052cef..77960bb19 100644
--- a/app/abilities/item_ability.rb
+++ b/app/abilities/item_ability.rb
@@ -6,9 +6,9 @@ def initialize(user)
 
     can [:create, :update, :edit, :destroy], Item do |item|
       (item.medium.nil? && !user.generic?) ||
-      (item.medium && user.can_edit?(item.medium))
+        (item.medium && user.can_edit?(item.medium))
     end
 
     can :display, Item
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/lecture_ability.rb b/app/abilities/lecture_ability.rb
index 5480923c4..4794e679c 100644
--- a/app/abilities/lecture_ability.rb
+++ b/app/abilities/lecture_ability.rb
@@ -36,4 +36,4 @@ def initialize(user)
       lecture.published? || !user.generic?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/lesson_ability.rb b/app/abilities/lesson_ability.rb
index 0ee9afabd..c1af01c98 100644
--- a/app/abilities/lesson_ability.rb
+++ b/app/abilities/lesson_ability.rb
@@ -12,4 +12,4 @@ def initialize(user)
       user.can_edit?(lesson)
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/main_ability.rb b/app/abilities/main_ability.rb
index bd65084b6..7ced6bc32 100644
--- a/app/abilities/main_ability.rb
+++ b/app/abilities/main_ability.rb
@@ -4,4 +4,4 @@ class MainAbility
   def initialize(user)
     can :start, :main
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/medium_ability.rb b/app/abilities/medium_ability.rb
index 1a39a4d36..f173dd07c 100644
--- a/app/abilities/medium_ability.rb
+++ b/app/abilities/medium_ability.rb
@@ -8,8 +8,8 @@ def initialize(user)
     can [:index, :new, :search], Medium
 
     can [:show, :show_comments], Medium do |medium|
-      medium.visible_for_user?(user)  &&
-      !(medium.sort.in?(['Question', 'Remark']) && !user.can_edit?(medium))
+      medium.visible_for_user?(user) &&
+        !(medium.sort.in?(['Question', 'Remark']) && !user.can_edit?(medium))
     end
 
     can :inspect, Medium do |medium|
@@ -39,7 +39,7 @@ def initialize(user)
     # guest users can play/display media when their release status 'all'
     can [:play, :display, :geogebra], Medium do |medium|
       (!user.new_record? && medium.visible_for_user?(user)) ||
-      medium.free?
+        medium.free?
     end
 
     can :update_tags, Medium do |medium|
@@ -50,4 +50,4 @@ def initialize(user)
       !user.new_record?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/notification_ability.rb b/app/abilities/notification_ability.rb
index 89fe5d7d1..a3b9abd0c 100644
--- a/app/abilities/notification_ability.rb
+++ b/app/abilities/notification_ability.rb
@@ -11,4 +11,4 @@ def initialize(user)
       notification.recipient == user
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/profile_ability.rb b/app/abilities/profile_ability.rb
index 9370bbc77..3000ca054 100644
--- a/app/abilities/profile_ability.rb
+++ b/app/abilities/profile_ability.rb
@@ -8,4 +8,4 @@ def initialize(user)
          :toggle_thread_subscription, :subscribe_lecture, :unsubscribe_lecture,
          :star_lecture, :unstar_lecture, :show_accordion, :request_data], :profile
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/program_ability.rb b/app/abilities/program_ability.rb
index 4b691a242..50c586533 100644
--- a/app/abilities/program_ability.rb
+++ b/app/abilities/program_ability.rb
@@ -8,4 +8,4 @@ def initialize(user)
       user.admin?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/question_ability.rb b/app/abilities/question_ability.rb
index c921d7fca..1d20d8d27 100644
--- a/app/abilities/question_ability.rb
+++ b/app/abilities/question_ability.rb
@@ -10,4 +10,4 @@ def initialize(user)
       user.can_edit?(question)
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/quiz_ability.rb b/app/abilities/quiz_ability.rb
index 57372048e..4032d5125 100644
--- a/app/abilities/quiz_ability.rb
+++ b/app/abilities/quiz_ability.rb
@@ -13,4 +13,4 @@ def initialize(user)
       quiz && user.can_edit?(quiz.becomes(Medium))
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/quiz_certificate_ability.rb b/app/abilities/quiz_certificate_ability.rb
index 206827a25..31bca228f 100644
--- a/app/abilities/quiz_certificate_ability.rb
+++ b/app/abilities/quiz_certificate_ability.rb
@@ -10,4 +10,4 @@ def initialize(user)
       user.tutor? || !user.generic?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/referral_ability.rb b/app/abilities/referral_ability.rb
index 08bbd413e..138ba4df7 100644
--- a/app/abilities/referral_ability.rb
+++ b/app/abilities/referral_ability.rb
@@ -12,4 +12,4 @@ def initialize(user)
       !user.generic? || user.media_editor?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/remark_ability.rb b/app/abilities/remark_ability.rb
index 846798578..63b4810e7 100644
--- a/app/abilities/remark_ability.rb
+++ b/app/abilities/remark_ability.rb
@@ -8,4 +8,4 @@ def initialize(user)
       user.can_edit?(remark)
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/search_ability.rb b/app/abilities/search_ability.rb
index 499fee1bc..018392d85 100644
--- a/app/abilities/search_ability.rb
+++ b/app/abilities/search_ability.rb
@@ -6,4 +6,4 @@ def initialize(user)
 
     can :index, :search
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/section_ability.rb b/app/abilities/section_ability.rb
index 1182aece4..215b19c34 100644
--- a/app/abilities/section_ability.rb
+++ b/app/abilities/section_ability.rb
@@ -13,4 +13,4 @@ def initialize(user)
       user.can_edit?(section.lecture)
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/subject_ability.rb b/app/abilities/subject_ability.rb
index 9dd2944e3..4961d65ef 100644
--- a/app/abilities/subject_ability.rb
+++ b/app/abilities/subject_ability.rb
@@ -8,4 +8,4 @@ def initialize(user)
       user.admin?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/submission_ability.rb b/app/abilities/submission_ability.rb
index d3ffaeff1..5905c72a0 100644
--- a/app/abilities/submission_ability.rb
+++ b/app/abilities/submission_ability.rb
@@ -19,9 +19,9 @@ def initialize(user)
     end
 
     can [:show_manuscript, :show_correction], Submission do |submission|
-       user.in?(submission.users) || user.in?(submission.tutorial.tutors) ||
-       user.in?(submission.tutorial.lecture.editors) ||
-       user == submission.tutorial.lecture.teacher
+      user.in?(submission.users) || user.in?(submission.tutorial.tutors) ||
+        user.in?(submission.tutorial.lecture.editors) ||
+        user == submission.tutorial.lecture.teacher
     end
   end
 end
diff --git a/app/abilities/tag_ability.rb b/app/abilities/tag_ability.rb
index 0ddad1cf6..c04cd4c90 100644
--- a/app/abilities/tag_ability.rb
+++ b/app/abilities/tag_ability.rb
@@ -13,4 +13,3 @@ def initialize(user)
     end
   end
 end
-
diff --git a/app/abilities/term_ability.rb b/app/abilities/term_ability.rb
index 6daba388d..51a20e8af 100644
--- a/app/abilities/term_ability.rb
+++ b/app/abilities/term_ability.rb
@@ -9,4 +9,4 @@ def initialize(user)
       user.admin?
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/abilities/tutorial_ability.rb b/app/abilities/tutorial_ability.rb
index d17014db1..fa6087ac6 100644
--- a/app/abilities/tutorial_ability.rb
+++ b/app/abilities/tutorial_ability.rb
@@ -20,7 +20,7 @@ def initialize(user)
     can [:bulk_download_submissions, :bulk_download_corrections, :bulk_upload,
          :export_teams], Tutorial do |tutorial|
       user.in?(tutorial.tutors) ||
-      user.editor_or_teacher_in?(tutorial.lecture)
+        user.editor_or_teacher_in?(tutorial.lecture)
     end
 
     can :validate_certificate, Tutorial do
@@ -28,7 +28,3 @@ def initialize(user)
     end
   end
 end
-
-
-
-
diff --git a/app/abilities/watchlist_ability.rb b/app/abilities/watchlist_ability.rb
index 67fb84bec..9b7c89044 100644
--- a/app/abilities/watchlist_ability.rb
+++ b/app/abilities/watchlist_ability.rb
@@ -20,4 +20,4 @@ def initialize(user)
         entries.all? { |entry| entry&.in?(watchlist.watchlist_entries) }
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/controllers/announcements_controller.rb b/app/controllers/announcements_controller.rb
index 454cb6e03..ba3492fff 100644
--- a/app/controllers/announcements_controller.rb
+++ b/app/controllers/announcements_controller.rb
@@ -55,49 +55,50 @@ def expel
 
   private
 
-  def announcement_params
-    params.require(:announcement).permit(:details, :lecture_id, :on_main_page)
-  end
+    def announcement_params
+      params.require(:announcement).permit(:details, :lecture_id, :on_main_page)
+    end
 
-  def create_notifications
-    users_to_notify = if @announcement.lecture.present?
-                        @announcement.lecture.users
-                      else
-                        User
-                      end
-    notifications = []
-    users_to_notify.update_all(updated_at: Time.now)
-    users_to_notify.find_each do |u|
-      notifications << Notification.new(recipient: u,
-                                        notifiable_id: @announcement.id,
-                                        notifiable_type: 'Announcement',
-                                        action: 'create')
+    def create_notifications
+      users_to_notify = if @announcement.lecture.present?
+        @announcement.lecture.users
+      else
+        User
+      end
+      notifications = []
+      users_to_notify.update_all(updated_at: Time.now)
+      users_to_notify.find_each do |u|
+        notifications << Notification.new(recipient: u,
+                                          notifiable_id: @announcement.id,
+                                          notifiable_type: 'Announcement',
+                                          action: 'create')
+      end
+      # use activerecord-import gem to use only one SQL instruction
+      Notification.import notifications
     end
-    # use activerecord-import gem to use only one SQL instruction
-    Notification.import notifications
-  end
 
-  def send_notification_email
-    recipients = if @announcement.lecture.present?
-                   @announcement.lecture.users
-                                .where(email_for_announcement: true)
-                 else
-                   User.where(email_for_news: true)
-                 end
-    I18n.available_locales.each do |l|
-      local_recipients = recipients.where(locale: l)
-      if local_recipients.any?
-        NotificationMailer.with(recipients: local_recipients.pluck(:id),
-                                locale: l,
-                                announcement: @announcement)
-                          .announcement_email.deliver_later
+    def send_notification_email
+      recipients = if @announcement.lecture.present?
+        @announcement.lecture.users
+                     .where(email_for_announcement: true)
+      else
+        User.where(email_for_news: true)
+      end
+      I18n.available_locales.each do |l|
+        local_recipients = recipients.where(locale: l)
+        if local_recipients.any?
+          NotificationMailer.with(recipients: local_recipients.pluck(:id),
+                                  locale: l,
+                                  announcement: @announcement)
+                            .announcement_email.deliver_later
+        end
       end
     end
-  end
 
-  def set_announcement
-    @announcement = Announcement.find_by_id(params[:id])
-    return if @announcement.present?
-    redirect_to :root, alert: I18n.t('controllers.no_announcement')
-  end
+    def set_announcement
+      @announcement = Announcement.find_by_id(params[:id])
+      return if @announcement.present?
+
+      redirect_to :root, alert: I18n.t('controllers.no_announcement')
+    end
 end
diff --git a/app/controllers/answers_controller.rb b/app/controllers/answers_controller.rb
index 0b5ec5916..8e0441d4d 100644
--- a/app/controllers/answers_controller.rb
+++ b/app/controllers/answers_controller.rb
@@ -19,6 +19,7 @@ def create
     authorize! :create, @answer
     I18n.locale = @answer.question&.locale_with_inheritance
     return unless @answer.save
+
     @success = true
   end
 
@@ -29,6 +30,7 @@ def update
   def destroy
     @id = params[:id]
     return unless @answer.destroy
+
     @success = true
   end
 
@@ -39,13 +41,14 @@ def update_answer_box
 
   private
 
-  def set_answer
-    @answer = Answer.find_by_id(params[:id])
-    return if @answer.present?
-    redirect_to root_path, alert: I18n.t('controllers.no_answer')
-  end
+    def set_answer
+      @answer = Answer.find_by_id(params[:id])
+      return if @answer.present?
 
-  def answer_params
-    params.require(:answer).permit(:text, :value, :explanation, :question_id)
-  end
+      redirect_to root_path, alert: I18n.t('controllers.no_answer')
+    end
+
+    def answer_params
+      params.require(:answer).permit(:text, :value, :explanation, :question_id)
+    end
 end
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 76550fadb..a19c8553f 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -9,13 +9,13 @@ class ApplicationController < ActionController::Base
   before_action :set_locale
   after_action :store_interaction, if: :user_signed_in?
 
-
   etag { current_user.try :id }
 
   def current_user
-    unless controller_name == 'administration' &&  action_name == 'index'
+    unless controller_name == 'administration' && action_name == 'index'
       return super
     end
+
     @current_user ||= super.tap do |user|
       ::ActiveRecord::Associations::Preloader.new(records: [user],
                                                   associations:
@@ -46,7 +46,7 @@ def current_user
 
   rescue_from ActionController::InvalidAuthenticityToken do
     redirect_to main_app.root_url,
-      alert: I18n.t('controllers.session_expired')
+                alert: I18n.t('controllers.session_expired')
   end
 
   # determine where to send the user after login
@@ -69,65 +69,69 @@ def prevent_caching
 
   protected
 
-  def configure_permitted_parameters
-    # add additional paramters to registration
-    devise_parameter_sanitizer.permit(:sign_up, keys: [:locale, :consents])
-  end
+    def configure_permitted_parameters
+      # add additional paramters to registration
+      devise_parameter_sanitizer.permit(:sign_up, keys: [:locale, :consents])
+    end
 
   private
 
-  # It's important that the location is NOT stored if:
-  # - The request method is not GET (non idempotent)
-  # - The request is handled by a Devise controller such as
-  #   Devise::SessionsController as that could cause an
-  #   infinite redirect loop.
-  # - The request is an Ajax request as this can lead to very
-  #   unexpected behaviour.
-  def storable_location?
-    request.get? && is_navigational_format? && !devise_controller? &&
-      !request.xhr?
-  end
+    # It's important that the location is NOT stored if:
+    # - The request method is not GET (non idempotent)
+    # - The request is handled by a Devise controller such as
+    #   Devise::SessionsController as that could cause an
+    #   infinite redirect loop.
+    # - The request is an Ajax request as this can lead to very
+    #   unexpected behaviour.
+    def storable_location?
+      request.get? && is_navigational_format? && !devise_controller? &&
+        !request.xhr?
+    end
 
-  def store_user_location!
-    # :user is the scope we are authenticating
-    store_location_for(:user, request.fullpath)
-  end
+    def store_user_location!
+      # :user is the scope we are authenticating
+      store_location_for(:user, request.fullpath)
+    end
 
-  def set_locale
-    I18n.locale = current_user.try(:locale) || locale_param ||
+    def set_locale
+      I18n.locale = current_user.try(:locale) || locale_param ||
                     cookie_locale_param || I18n.default_locale
-    unless user_signed_in?
-      cookies[:locale] = I18n.locale
+      unless user_signed_in?
+        cookies[:locale] = I18n.locale
+      end
     end
-  end
 
-  def store_interaction
-    return if controller_name.in?(['sessions', 'administration', 'users',
-                                   'events', 'interactions', 'profile',
-                                   'clickers', 'clicker_votes', 'registrations'])
-    return if controller_name == 'main' && action_name == 'home'
-    return if controller_name == 'tags' && action_name.in?(['fill_tag_select', 'fill_course_tags'])
-    study_participant = current_user.anonymized_id if current_user.study_participant
-    # as of Rack 2.0.8, the session_id is wrapped in a class of its own
-    # it is not a string anymore
-    # see https://github.com/rack/rack/issues/1433
-    InteractionSaver.perform_async(request.session_options[:id].public_id,
-                                   request.original_fullpath,
-                                   request.referrer,
-                                   study_participant)
-  end
+    def store_interaction
+      return if controller_name.in?(['sessions', 'administration', 'users',
+                                     'events', 'interactions', 'profile',
+                                     'clickers', 'clicker_votes', 'registrations'])
+      return if controller_name == 'main' && action_name == 'home'
+      return if controller_name == 'tags' && action_name.in?(['fill_tag_select',
+                                                              'fill_course_tags'])
+
+      study_participant = current_user.anonymized_id if current_user.study_participant
+      # as of Rack 2.0.8, the session_id is wrapped in a class of its own
+      # it is not a string anymore
+      # see https://github.com/rack/rack/issues/1433
+      InteractionSaver.perform_async(request.session_options[:id].public_id,
+                                     request.original_fullpath,
+                                     request.referrer,
+                                     study_participant)
+    end
 
-  def locale_param
-    return unless params[:locale].in?(available_locales)
-    params[:locale]
-  end
+    def locale_param
+      return unless params[:locale].in?(available_locales)
 
-  def cookie_locale_param
-    return unless cookies[:locale].in?(available_locales)
-    cookies[:locale]
-  end
+      params[:locale]
+    end
 
-  def available_locales
-    I18n.available_locales.map(&:to_s)
-  end
+    def cookie_locale_param
+      return unless cookies[:locale].in?(available_locales)
+
+      cookies[:locale]
+    end
+
+    def available_locales
+      I18n.available_locales.map(&:to_s)
+    end
 end
diff --git a/app/controllers/assignments_controller.rb b/app/controllers/assignments_controller.rb
index 6dd2a2ad3..9f2b97f09 100644
--- a/app/controllers/assignments_controller.rb
+++ b/app/controllers/assignments_controller.rb
@@ -32,6 +32,7 @@ def update
     @assignment.update(assignment_params)
     @errors = @assignment.errors
     return if @errors.present?
+
     @assignment.update(medium: nil) if assignment_params[:medium_id].blank?
   end
 
@@ -52,27 +53,29 @@ def cancel_new
 
   private
 
-  def set_assignment
-    @assignment = Assignment.find_by_id(params[:id])
-    @lecture = @assignment&.lecture
-    set_assignment_locale and return if @assignment
-    redirect_to :root, alert: I18n.t('controllers.no_assignment')
-  end
+    def set_assignment
+      @assignment = Assignment.find_by_id(params[:id])
+      @lecture = @assignment&.lecture
+      set_assignment_locale and return if @assignment
 
-  def set_lecture
-    @lecture = Lecture.find_by_id(assignment_params[:lecture_id])
-    return if @lecture
-    redirect_to :root, alert: I18n.t('controllers.no_lecture')
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_assignment')
+    end
+
+    def set_lecture
+      @lecture = Lecture.find_by_id(assignment_params[:lecture_id])
+      return if @lecture
 
-  def set_assignment_locale
-    I18n.locale = @lecture&.locale_with_inheritance || current_user.locale ||
+      redirect_to :root, alert: I18n.t('controllers.no_lecture')
+    end
+
+    def set_assignment_locale
+      I18n.locale = @lecture&.locale_with_inheritance || current_user.locale ||
                     I18n.default_locale
-  end
+    end
 
-  def assignment_params
-    params.require(:assignment).permit(:title, :medium_id, :lecture_id,
-                                       :deadline, :accepted_file_type,
-                                       :deletion_date)
-  end
-end
\ No newline at end of file
+    def assignment_params
+      params.require(:assignment).permit(:title, :medium_id, :lecture_id,
+                                         :deadline, :accepted_file_type,
+                                         :deletion_date)
+    end
+end
diff --git a/app/controllers/chapters_controller.rb b/app/controllers/chapters_controller.rb
index 60e3ce7ab..1b6188a3c 100644
--- a/app/controllers/chapters_controller.rb
+++ b/app/controllers/chapters_controller.rb
@@ -15,7 +15,7 @@ def edit
 
   def update
     I18n.locale = @chapter.lecture.locale_with_inheritance ||
-                    current_user.locale || I18n.default_locale
+                  current_user.locale || I18n.default_locale
     @chapter.update(chapter_params)
     if @chapter.valid?
       predecessor = params[:chapter][:predecessor]
@@ -35,7 +35,7 @@ def create
     @chapter = Chapter.new(chapter_params)
     authorize! :create, @chapter
     I18n.locale = @chapter&.lecture&.locale_with_inheritance ||
-                    current_user.locale || I18n.default_locale
+                  current_user.locale || I18n.default_locale
     position = params[:chapter][:predecessor]
     # place the chapter in the correct position
     if position.present?
@@ -52,7 +52,7 @@ def new
     @chapter = Chapter.new(lecture: @lecture)
     authorize! :new, @chapter
     I18n.locale = @chapter.lecture.locale_with_inheritance ||
-                    current_user.locale || I18n.default_locale
+                  current_user.locale || I18n.default_locale
   end
 
   def destroy
@@ -68,19 +68,20 @@ def list_sections
 
   private
 
-  def set_chapter
-    @chapter = Chapter.find_by_id(params[:id])
-    return if @chapter.present?
-    redirect_to :root, alert: I18n.t('controllers.no_chapter')
-  end
+    def set_chapter
+      @chapter = Chapter.find_by_id(params[:id])
+      return if @chapter.present?
 
-  def chapter_params
-    params.require(:chapter).permit(:title, :display_number, :lecture_id,
-                                    :hidden, :details)
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_chapter')
+    end
 
-  def set_view_locale
-    I18n.locale = @chapter.lecture.locale_with_inheritance ||
+    def chapter_params
+      params.require(:chapter).permit(:title, :display_number, :lecture_id,
+                                      :hidden, :details)
+    end
+
+    def set_view_locale
+      I18n.locale = @chapter.lecture.locale_with_inheritance ||
                     current_user.locale || I18n.default_locale
-  end
+    end
 end
diff --git a/app/controllers/clicker_votes_controller.rb b/app/controllers/clicker_votes_controller.rb
index 5ed76326b..d2b684e04 100644
--- a/app/controllers/clicker_votes_controller.rb
+++ b/app/controllers/clicker_votes_controller.rb
@@ -16,7 +16,7 @@ def create
 
   private
 
-  def vote_params
-    params.require(:clicker_vote).permit(:clicker_id, :value)
-  end
+    def vote_params
+      params.require(:clicker_vote).permit(:clicker_id, :value)
+    end
 end
diff --git a/app/controllers/clickers_controller.rb b/app/controllers/clickers_controller.rb
index e517ff421..55ced38b8 100644
--- a/app/controllers/clickers_controller.rb
+++ b/app/controllers/clickers_controller.rb
@@ -112,20 +112,21 @@ def render_clickerizable_actions
 
   private
 
-  def clicker_params
-    params.require(:clicker).permit(:editor_id, :teachable_type,
-                                    :teachable_id, :question_id, :title)
-  end
+    def clicker_params
+      params.require(:clicker).permit(:editor_id, :teachable_type,
+                                      :teachable_id, :question_id, :title)
+    end
 
-  def code_params
-    params.permit(:code)
-  end
+    def code_params
+      params.permit(:code)
+    end
 
-  def set_clicker
-    @clicker = Clicker.find_by_id(params[:id])
-    @code = user_signed_in? ? nil : @clicker&.code
-    @entered_code = code_params[:code]
-    return if @clicker
-    redirect_to :root, alert: I18n.t('controllers.no_clicker')
-  end
-end
\ No newline at end of file
+    def set_clicker
+      @clicker = Clicker.find_by_id(params[:id])
+      @code = user_signed_in? ? nil : @clicker&.code
+      @entered_code = code_params[:code]
+      return if @clicker
+
+      redirect_to :root, alert: I18n.t('controllers.no_clicker')
+    end
+end
diff --git a/app/controllers/confirmations_controller.rb b/app/controllers/confirmations_controller.rb
index 8acec71a3..b0fd5e1ed 100644
--- a/app/controllers/confirmations_controller.rb
+++ b/app/controllers/confirmations_controller.rb
@@ -1,9 +1,8 @@
 class ConfirmationsController < Devise::ConfirmationsController
-
   private
 
-  def after_confirmation_path_for(resource_name, resource)
-    sign_in(resource) # In case you want to sign in the user
-    edit_profile_path
-  end
-end
\ No newline at end of file
+    def after_confirmation_path_for(resource_name, resource)
+      sign_in(resource) # In case you want to sign in the user
+      edit_profile_path
+    end
+end
diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index bc28a96c8..67be24754 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -21,6 +21,7 @@ def update
     @course.update(course_params)
     @errors = @course.errors
     return unless @errors.empty?
+
     @course.update(image: nil) if params[:course][:detach_image] == 'true'
     changed_image = @course.image_data != old_image_data
     if @course.image.present? && changed_image
@@ -56,7 +57,8 @@ def destroy
 
   def take_random_quiz
     tags = Tag.where(id: random_quiz_params[:search_course_tag_ids])
-    random_quiz = @course.create_random_quiz!(tags, random_quiz_params[:random_quiz_count].to_i)
+    random_quiz = @course.create_random_quiz!(tags,
+                                              random_quiz_params[:random_quiz_count].to_i)
     redirect_to take_quiz_path(random_quiz)
   end
 
@@ -72,70 +74,73 @@ def search
     results = search.results
     @total = search.total
     @courses = Kaminari.paginate_array(results, total_count: @total)
-                        .page(params[:page]).per(search_params[:per])
+                       .page(params[:page]).per(search_params[:per])
   end
 
   private
 
-  def set_course
-    @course = Course.find_by_id(params[:id])
-    return if @course.present?
-    redirect_to :root, alert: I18n.t('controllers.no_course')
-  end
+    def set_course
+      @course = Course.find_by_id(params[:id])
+      return if @course.present?
 
-  def set_course_admin
-    @course = Course.find_by_id(params[:id])
-    return if @course.present?
-    redirect_to administration_path
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_course')
+    end
 
-  def course_params
-    params.require(:course).permit(:title, :short_title, :organizational,
-                                   :organizational_concept, :locale,
-                                   :term_independent, :image,
-                                   tag_ids: [],
-                                   preceding_course_ids: [],
-                                   editor_ids: [],
-                                   division_ids: [])
-  end
+    def set_course_admin
+      @course = Course.find_by_id(params[:id])
+      return if @course.present?
 
-  def tag_params
-    params.permit(:count, tag_ids: [])
-  end
+      redirect_to administration_path
+    end
 
-  def search_params
-    params.require(:search).permit(:all_editors, :all_programs, :fulltext,
-                                   :term_independent, :per,
-                                   editor_ids: [],
-                                   program_ids: [])
-  end
+    def course_params
+      params.require(:course).permit(:title, :short_title, :organizational,
+                                     :organizational_concept, :locale,
+                                     :term_independent, :image,
+                                     tag_ids: [],
+                                     preceding_course_ids: [],
+                                     editor_ids: [],
+                                     division_ids: [])
+    end
 
-  def random_quiz_params
-    params.require(:quiz).permit(:random_quiz_count,
-                                 search_course_tag_ids: [])
-  end
+    def tag_params
+      params.permit(:count, tag_ids: [])
+    end
 
-  # destroy all notifications related to this course
-  def destroy_notifications
-    Notification.where(notifiable_id: @course.id, notifiable_type: 'Course')
-                .delete_all
-  end
+    def search_params
+      params.require(:search).permit(:all_editors, :all_programs, :fulltext,
+                                     :term_independent, :per,
+                                     editor_ids: [],
+                                     program_ids: [])
+    end
 
-  # fill organizational_concept with default view
-  def set_organizational_defaults
-    @course.update(organizational_concept:
-                     render_to_string(partial: 'courses/' \
-                                               'organizational_default',
-                                      formats: :html,
-                                      layout: false))
-  end
+    def random_quiz_params
+      params.require(:quiz).permit(:random_quiz_count,
+                                   search_course_tag_ids: [])
+    end
 
-  def check_if_enough_questions
-    return if @course.enough_questions?
-    redirect_to :root, alert: I18n.t('controllers.no_test')
-  end
+    # destroy all notifications related to this course
+    def destroy_notifications
+      Notification.where(notifiable_id: @course.id, notifiable_type: 'Course')
+                  .delete_all
+    end
 
-  def check_for_consent
-    redirect_to consent_profile_path unless current_user.consents
-  end
+    # fill organizational_concept with default view
+    def set_organizational_defaults
+      @course.update(organizational_concept:
+                       render_to_string(partial: 'courses/' \
+                                                 'organizational_default',
+                                        formats: :html,
+                                        layout: false))
+    end
+
+    def check_if_enough_questions
+      return if @course.enough_questions?
+
+      redirect_to :root, alert: I18n.t('controllers.no_test')
+    end
+
+    def check_for_consent
+      redirect_to consent_profile_path unless current_user.consents
+    end
 end
diff --git a/app/controllers/divisions_controller.rb b/app/controllers/divisions_controller.rb
index c683c4d0f..9c8ecdd53 100644
--- a/app/controllers/divisions_controller.rb
+++ b/app/controllers/divisions_controller.rb
@@ -7,42 +7,42 @@ def current_ability
     @current_ability ||= DivisionAbility.new(current_user)
   end
 
-	def edit
-	end
+  def edit
+  end
 
-	def new
-		@division = Division.new(program_id: params[:program_id].to_i)
+  def new
+    @division = Division.new(program_id: params[:program_id].to_i)
     authorize! :new, @division
-	end
+  end
 
-	def update
-		@division.update(division_params)
-		redirect_to classification_path
-	end
+  def update
+    @division.update(division_params)
+    redirect_to classification_path
+  end
 
-	def create
-		@division = Division.new(division_params)
-		@division.program_id = params[:division][:program_id]
+  def create
+    @division = Division.new(division_params)
+    @division.program_id = params[:division][:program_id]
     authorize! :create, @division
-		@division.save
-		redirect_to classification_path
-	end
+    @division.save
+    redirect_to classification_path
+  end
 
-	def destroy
-		@division.destroy
-		redirect_to classification_path
-	end
+  def destroy
+    @division.destroy
+    redirect_to classification_path
+  end
 
   private
 
-  def set_division
-    @division = Division.find_by_id(params[:id])
-    return if @division.present?
+    def set_division
+      @division = Division.find_by_id(params[:id])
+      return if @division.present?
 
-    redirect_to root_path, alert: I18n.t('controllers.no_division')
-  end
+      redirect_to root_path, alert: I18n.t('controllers.no_division')
+    end
 
-  def division_params
-  	params.require(:division).permit(*Division.globalize_attribute_names)
-  end
-end
\ No newline at end of file
+    def division_params
+      params.require(:division).permit(*Division.globalize_attribute_names)
+    end
+end
diff --git a/app/controllers/erdbeere_controller.rb b/app/controllers/erdbeere_controller.rb
index 22081e47c..d880b9114 100644
--- a/app/controllers/erdbeere_controller.rb
+++ b/app/controllers/erdbeere_controller.rb
@@ -1,46 +1,46 @@
 # ExamplesController
 class ErdbeereController < ApplicationController
   authorize_resource class: false
-	layout 'application'
+  layout 'application'
 
   def current_ability
     @current_ability ||= ErdbeereAbility.new(current_user)
   end
 
-	def show_example
+  def show_example
     response = Faraday.get(ENV['ERDBEERE_API'] + "/examples/#{params[:id]}")
     @content = if response.status == 200
-								 JSON.parse(response.body)['embedded_html']
-							 else
-							 	 'Something went wrong.'
-							 end
-	end
+      JSON.parse(response.body)['embedded_html']
+    else
+      'Something went wrong.'
+    end
+  end
 
-	def show_property
+  def show_property
     response = Faraday.get(ENV['ERDBEERE_API'] + "/properties/#{params[:id]}")
 
-		@content = if response.status == 200
-								 JSON.parse(response.body)['embedded_html']
-							 else
-							 	 'Something went wrong.'
-							 end
-	end
+    @content = if response.status == 200
+      JSON.parse(response.body)['embedded_html']
+    else
+      'Something went wrong.'
+    end
+  end
 
-	def show_structure
-		id = params[:id]
+  def show_structure
+    id = params[:id]
     response = Faraday.get(ENV['ERDBEERE_API'] + "/structures/#{params[:id]}")
     @content = if response.status == 200
-								 JSON.parse(response.body)['embedded_html']
-							 else
-							 	 'Something went wrong.'
-							 end
-	end
+      JSON.parse(response.body)['embedded_html']
+    else
+      'Something went wrong.'
+    end
+  end
 
-	def find_tags
-		@sort = params[:sort]
-		@id = params[:id].to_i
-		@tags = Tag.find_erdbeere_tags(@sort, @id)
-	end
+  def find_tags
+    @sort = params[:sort]
+    @id = params[:id].to_i
+    @tags = Tag.find_erdbeere_tags(@sort, @id)
+  end
 
   def edit_tags
   end
@@ -59,11 +59,11 @@ def display_info
       return
     end
     @info = if @sort == 'Structure'
-              @content['data']['attributes']['name']
-            else
-              "#{@content['included'][0]['attributes']['name']}:"\
-              "#{@content['data']['attributes']['name']}"
-            end
+      @content['data']['attributes']['name']
+    else
+      "#{@content['included'][0]['attributes']['name']}:"\
+      "#{@content['data']['attributes']['name']}"
+    end
   end
 
   def update_tags
@@ -93,7 +93,9 @@ def fill_realizations_select
     @structures = hash['data'].map do |d|
       { id: d['id'],
         name: d['attributes']['name'],
-        properties: d['relationships']['original_properties']['data'].map { |x| x['id'] }}
+        properties: d['relationships']['original_properties']['data'].map { |x|
+                      x['id']
+                    } }
     end
     @properties = hash['included'].map do |d|
       { id: d['id'],
@@ -104,21 +106,21 @@ def fill_realizations_select
   def find_example
     response = Faraday.get(ENV['ERDBEERE_API'] + '/find?' + find_params.to_query)
     @content = if response.status == 200
-                 JSON.parse(response.body)['embedded_html']
-               else
-                 'Something went wrong.'
-               end
+      JSON.parse(response.body)['embedded_html']
+    else
+      'Something went wrong.'
+    end
   end
 
   private
 
-  def erdbeere_params
-    params.require(:erdbeere).permit(:sort, :id, tag_ids: [])
-  end
+    def erdbeere_params
+      params.require(:erdbeere).permit(:sort, :id, tag_ids: [])
+    end
 
-  def find_params
-    params.require(:find).permit(:structure_id,
-                                 satisfies: [],
-                                 violates: [])
-  end
-end
\ No newline at end of file
+    def find_params
+      params.require(:find).permit(:structure_id,
+                                   satisfies: [],
+                                   violates: [])
+    end
+end
diff --git a/app/controllers/interactions_controller.rb b/app/controllers/interactions_controller.rb
index 5892ed34b..81242996b 100644
--- a/app/controllers/interactions_controller.rb
+++ b/app/controllers/interactions_controller.rb
@@ -7,30 +7,34 @@ def index
   end
 
   def export_interactions
-  	start_date = interaction_params[:start_date].to_date
-		end_date = interaction_params[:end_date].to_date
-  	@interactions = Interaction.created_between(start_date, end_date)
+    start_date = interaction_params[:start_date].to_date
+    end_date = interaction_params[:end_date].to_date
+    @interactions = Interaction.created_between(start_date, end_date)
     respond_to do |format|
       format.html { head :ok }
-      format.csv { send_data @interactions.to_csv,
-      											 filename: "interactions-from-#{start_date}-to-#{end_date}-at-#{Time.now}.csv" }
+      format.csv {
+        send_data @interactions.to_csv,
+                  filename: "interactions-from-#{start_date}-to-#{end_date}-at-#{Time.now}.csv"
+      }
     end
   end
 
   def export_probes
-  	start_date = interaction_params[:start_date].to_date
-		end_date = interaction_params[:end_date].to_date
-  	@probes = Probe.created_between(start_date, end_date)
+    start_date = interaction_params[:start_date].to_date
+    end_date = interaction_params[:end_date].to_date
+    @probes = Probe.created_between(start_date, end_date)
     respond_to do |format|
       format.html { head :ok }
-      format.csv { send_data @probes.to_csv,
-      											 filename: "probes-from-#{start_date}-to-#{end_date}-at-#{Time.now}.csv" }
+      format.csv {
+        send_data @probes.to_csv,
+                  filename: "probes-from-#{start_date}-to-#{end_date}-at-#{Time.now}.csv"
+      }
     end
   end
 
   private
 
-  def interaction_params
-  	params.require(:interactions).permit(:start_date, :end_date)
- 	end
-end
\ No newline at end of file
+    def interaction_params
+      params.require(:interactions).permit(:start_date, :end_date)
+    end
+end
diff --git a/app/controllers/items_controller.rb b/app/controllers/items_controller.rb
index 67ec44559..56c0bf885 100644
--- a/app/controllers/items_controller.rb
+++ b/app/controllers/items_controller.rb
@@ -50,27 +50,28 @@ def display
 
   private
 
-  def set_item
-    @item = Item.find(params[:id])
-  end
+    def set_item
+      @item = Item.find(params[:id])
+    end
+
+    def set_explanation
+      if @referral_id.zero? || @item != Referral.find(@referral_id).item
+        return @item.explanation
+      end
 
-  def set_explanation
-    if @referral_id.zero? || @item != Referral.find(@referral_id).item
-      return @item.explanation
+      Referral.find(@referral_id).explanation
     end
-    Referral.find(@referral_id).explanation
-  end
 
-  def item_params
-    # params are cloned and then start time is converted to a TimeStamp object
-    filter = params.require(:item).permit(:sort, :start_time, :section_id,
-                                          :medium_id, :ref_number, :description,
-                                          :link, :page, :pdf_destination,
-                                          :explanation, :hidden).clone
-    if filter[:medium_id].present?
-      filter[:start_time] = TimeStamp.new(time_string: filter[:start_time])
+    def item_params
+      # params are cloned and then start time is converted to a TimeStamp object
+      filter = params.require(:item).permit(:sort, :start_time, :section_id,
+                                            :medium_id, :ref_number, :description,
+                                            :link, :page, :pdf_destination,
+                                            :explanation, :hidden).clone
+      if filter[:medium_id].present?
+        filter[:start_time] = TimeStamp.new(time_string: filter[:start_time])
+      end
+      filter[:section_id] = nil if filter[:section_id] == ''
+      filter
     end
-    filter[:section_id] = nil if filter[:section_id] == ''
-    filter
-  end
 end
diff --git a/app/controllers/lectures_controller.rb b/app/controllers/lectures_controller.rb
index bf7a63ffb..bf1aab76c 100644
--- a/app/controllers/lectures_controller.rb
+++ b/app/controllers/lectures_controller.rb
@@ -44,11 +44,11 @@ def update
                           .new_editor_email.deliver_later
       end
     end
-    
+
     @lecture.update(lecture_params)
     if structure_params.present?
       structure_ids = structure_params.select { |_k, v| v.to_i == 1 }.keys
-                        .map(&:to_i)
+                                      .map(&:to_i)
       @lecture.update(structure_ids: structure_ids)
     end
     @lecture.touch
@@ -74,7 +74,8 @@ def show
                                   chapters: [:lecture,
                                              sections: [lessons: [:tags],
                                                         chapter: [:lecture],
-                                                        tags: [:notions, :lessons]]])
+                                                        tags: [:notions,
+                                                               :lessons]]])
                         .find_by_id(params[:id])
       @notifications = current_user.active_notifications(@lecture)
       @new_topics_count = @lecture.unread_forum_topics_count(current_user) || 0
@@ -87,6 +88,7 @@ def new
     authorize! :new, @lecture
     @from = params[:from]
     return unless @from == 'course'
+
     # if new action was triggered from inside a course view, add the course
     # info to the lecture
     @lecture.course = Course.find_by_id(params[:course])
@@ -113,7 +115,7 @@ def create
       end
       redirect_to edit_course_path(@lecture.course),
                   notice: I18n.t('controllers.created_lecture_success',
-                                   lecture: @lecture.title_with_teacher)
+                                 lecture: @lecture.title_with_teacher)
       return
     end
     @errors = @lecture.errors
@@ -247,6 +249,7 @@ def search
     @results_as_list = search_params[:results_as_list] == 'true'
     return unless @total.zero?
     return unless search_params[:fulltext]&.length.to_i > 1
+
     @similar_titles = Course.similar_courses(search_params[:fulltext])
   end
 
@@ -267,7 +270,7 @@ def subscribe_page
 
   def import_toc
     imported_lecture = Lecture
-                         .find_by_id(import_toc_params[:imported_lecture_id])
+                       .find_by_id(import_toc_params[:imported_lecture_id])
     import_sections = import_toc_params[:import_sections] == '1'
     import_tags = import_toc_params[:import_tags] == '1'
     @lecture.import_toc!(imported_lecture, import_sections, import_tags)
@@ -276,154 +279,157 @@ def import_toc
 
   private
 
-  def set_lecture
-    @lecture = Lecture.find_by_id(params[:id])
-    return if @lecture
-    redirect_to :root, alert: I18n.t('controllers.no_lecture')
-  end
+    def set_lecture
+      @lecture = Lecture.find_by_id(params[:id])
+      return if @lecture
 
-  def set_lecture_cookie
-    cookies[:current_lecture_id] = @lecture.id
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_lecture')
+    end
 
-  def set_view_locale
-    I18n.locale = @lecture.locale_with_inheritance || current_user.locale ||
+    def set_lecture_cookie
+      cookies[:current_lecture_id] = @lecture.id
+    end
+
+    def set_view_locale
+      I18n.locale = @lecture.locale_with_inheritance || current_user.locale ||
                     I18n.default_locale
-  end
+    end
 
-  def check_for_consent
-    redirect_to consent_profile_path unless current_user.consents
-  end
+    def check_for_consent
+      redirect_to consent_profile_path unless current_user.consents
+    end
 
-  def check_for_subscribe
-    redirect_to subscribe_lecture_page_path(@lecture.id) unless @lecture.in?(current_user.lectures)
-  end
+    def check_for_subscribe
+      redirect_to subscribe_lecture_page_path(@lecture.id) unless @lecture.in?(current_user.lectures)
+    end
 
-  def lecture_params
-    params.require(:lecture).permit(:course_id, :term_id, :teacher_id,
-                                    :start_chapter, :absolute_numbering,
-                                    :start_section, :organizational, :locale,
-                                    :organizational_concept, :muesli,
-                                    :organizational_on_top,
-                                    :disable_teacher_display,
-                                    :content_mode, :passphrase, :sort,
-                                    :comments_disabled,
-                                    :submission_max_team_size,
-                                    :submission_grace_period,
-                                    editor_ids: [])
-  end
+    def lecture_params
+      params.require(:lecture).permit(:course_id, :term_id, :teacher_id,
+                                      :start_chapter, :absolute_numbering,
+                                      :start_section, :organizational, :locale,
+                                      :organizational_concept, :muesli,
+                                      :organizational_on_top,
+                                      :disable_teacher_display,
+                                      :content_mode, :passphrase, :sort,
+                                      :comments_disabled,
+                                      :submission_max_team_size,
+                                      :submission_grace_period,
+                                      editor_ids: [])
+    end
 
-  def structure_params
-    params.require(:lecture).permit(structures: {})[:structures]
-  end
+    def structure_params
+      params.require(:lecture).permit(structures: {})[:structures]
+    end
 
-  def comment_params
-    params.require(:lecture).permit(:close_comments)
-  end
+    def comment_params
+      params.require(:lecture).permit(:close_comments)
+    end
 
-  def import_toc_params
-    params.permit(:imported_lecture_id, :import_sections, :import_tags)
-  end
+    def import_toc_params
+      params.permit(:imported_lecture_id, :import_sections, :import_tags)
+    end
 
-  # create notifications to all users about creation of new lecture
-  def create_notifications
-    notifications = []
-    User.find_each do |u|
-      notifications << Notification.new(recipient: u,
-                                        notifiable_id: @lecture.id,
-                                        notifiable_type: 'Lecture',
-                                        action: 'create')
+    # create notifications to all users about creation of new lecture
+    def create_notifications
+      notifications = []
+      User.find_each do |u|
+        notifications << Notification.new(recipient: u,
+                                          notifiable_id: @lecture.id,
+                                          notifiable_type: 'Lecture',
+                                          action: 'create')
+      end
+      Notification.import notifications
     end
-    Notification.import notifications
-  end
 
-  def send_notification_email
-    recipients = User.where(email_for_teachable: true)
-    I18n.available_locales.each do |l|
-      local_recipients = recipients.where(locale: l)
-      if local_recipients.any?
-        NotificationMailer.with(recipients: local_recipients.pluck(:id),
-                                locale: l,
-                                lecture: @lecture)
-                          .new_lecture_email.deliver_later
+    def send_notification_email
+      recipients = User.where(email_for_teachable: true)
+      I18n.available_locales.each do |l|
+        local_recipients = recipients.where(locale: l)
+        if local_recipients.any?
+          NotificationMailer.with(recipients: local_recipients.pluck(:id),
+                                  locale: l,
+                                  lecture: @lecture)
+                            .new_lecture_email.deliver_later
+        end
       end
     end
-  end
 
-  # destroy all notifications related to this lecture
-  def destroy_notifications
-    Notification.where(notifiable_id: @lecture.id, notifiable_type: 'Lecture')
-                .delete_all
-  end
+    # destroy all notifications related to this lecture
+    def destroy_notifications
+      Notification.where(notifiable_id: @lecture.id, notifiable_type: 'Lecture')
+                  .delete_all
+    end
 
-  # fill organizational_concept with default view
-  def set_organizational_defaults
-    partial_path = 'lectures/organizational/'
-    partial_path += @lecture.seminar? ? 'seminar' : 'lecture'
-    @lecture.update(organizational_concept:
-                      render_to_string(partial: partial_path,
-                                       formats: :html,
-                                       layout: false))
-  end
+    # fill organizational_concept with default view
+    def set_organizational_defaults
+      partial_path = 'lectures/organizational/'
+      partial_path += @lecture.seminar? ? 'seminar' : 'lecture'
+      @lecture.update(organizational_concept:
+                        render_to_string(partial: partial_path,
+                                         formats: :html,
+                                         layout: false))
+    end
 
-  # set language to default language
-  def set_language
-    @lecture.update(locale: I18n.default_locale.to_s)
-  end
+    # set language to default language
+    def set_language
+      @lecture.update(locale: I18n.default_locale.to_s)
+    end
 
-  def eager_load_stuff
-    @lecture = Lecture.includes(:teacher, :term, :editors,
-                                :announcements, :imported_media,
-                                course: [:editors],
-                                media: [:teachable, :tags],
-                                lessons: [media: [:tags]],
-                                chapters: [:lecture,
-                                           sections: [lessons: [:tags],
-                                                      chapter: [:lecture],
-                                                      tags: [:notions, :lessons]]])
-                      .find_by_id(params[:id])
-    @media = @lecture.media_with_inheritance_uncached_eagerload_stuff
-    lecture_tags = @lecture.tags
-    @course_tags = @lecture.course_tags(lecture_tags: lecture_tags)
-    @extra_tags = @lecture.extra_tags(lecture_tags: lecture_tags)
-    @deferred_tags = @lecture.deferred_tags(lecture_tags: lecture_tags)
-    @announcements = @lecture.announcements.includes(:announcer).order(:created_at).reverse
-    @terms = Term.select_terms
-  end
+    def eager_load_stuff
+      @lecture = Lecture.includes(:teacher, :term, :editors,
+                                  :announcements, :imported_media,
+                                  course: [:editors],
+                                  media: [:teachable, :tags],
+                                  lessons: [media: [:tags]],
+                                  chapters: [:lecture,
+                                             sections: [lessons: [:tags],
+                                                        chapter: [:lecture],
+                                                        tags: [:notions,
+                                                               :lessons]]])
+                        .find_by_id(params[:id])
+      @media = @lecture.media_with_inheritance_uncached_eagerload_stuff
+      lecture_tags = @lecture.tags
+      @course_tags = @lecture.course_tags(lecture_tags: lecture_tags)
+      @extra_tags = @lecture.extra_tags(lecture_tags: lecture_tags)
+      @deferred_tags = @lecture.deferred_tags(lecture_tags: lecture_tags)
+      @announcements = @lecture.announcements.includes(:announcer).order(:created_at).reverse
+      @terms = Term.select_terms
+    end
 
-  def set_erdbeere_data
-    @structure_ids = @lecture.structure_ids
-    response = Faraday.get(ENV['ERDBEERE_API'] + '/structures')
-    response_hash = if response.status == 200
-                       JSON.parse(response.body)
-                     else
-                       { 'data' => {}, 'included' => {} }
-                     end
-    @all_structures = response_hash['data']
-    @structures = @all_structures.select do |s|
-      s['id'].to_i.in?(@structure_ids)
+    def set_erdbeere_data
+      @structure_ids = @lecture.structure_ids
+      response = Faraday.get(ENV['ERDBEERE_API'] + '/structures')
+      response_hash = if response.status == 200
+        JSON.parse(response.body)
+      else
+        { 'data' => {}, 'included' => {} }
+      end
+      @all_structures = response_hash['data']
+      @structures = @all_structures.select do |s|
+        s['id'].to_i.in?(@structure_ids)
+      end
+      @properties = response_hash['included']
     end
-    @properties = response_hash['included']
-  end
 
-  def search_params
-    types = params[:search][:types]
-    types = [types] if types && !types.kind_of?(Array)
-    types -= [''] if types
-    types = nil if types == []
-    params[:search][:types] = types
-    params[:search][:user_id] = current_user.id
-    params.require(:search).permit(:all_types, :all_terms, :all_programs,
-                                   :all_teachers, :fulltext, :per, :user_id,
-                                   :results_as_list,
-                                   types: [],
-                                   term_ids: [],
-                                   program_ids: [],
-                                   teacher_ids: [])
-  end
+    def search_params
+      types = params[:search][:types]
+      types = [types] if types && !types.kind_of?(Array)
+      types -= [''] if types
+      types = nil if types == []
+      params[:search][:types] = types
+      params[:search][:user_id] = current_user.id
+      params.require(:search).permit(:all_types, :all_terms, :all_programs,
+                                     :all_teachers, :fulltext, :per, :user_id,
+                                     :results_as_list,
+                                     types: [],
+                                     term_ids: [],
+                                     program_ids: [],
+                                     teacher_ids: [])
+    end
 
-  def check_if_enough_questions
-    return if @lecture.course.enough_questions?
-    redirect_to :root, alert: I18n.t('controllers.no_test')
-  end
+    def check_if_enough_questions
+      return if @lecture.course.enough_questions?
+
+      redirect_to :root, alert: I18n.t('controllers.no_test')
+    end
 end
diff --git a/app/controllers/lessons_controller.rb b/app/controllers/lessons_controller.rb
index 546c8a9e9..2425dce7d 100644
--- a/app/controllers/lessons_controller.rb
+++ b/app/controllers/lessons_controller.rb
@@ -46,9 +46,11 @@ def update
     @lesson.update(lesson_params)
     @errors = @lesson.errors
     return unless @errors.blank?
+
     update_media_order if params[:lesson][:media_order]
     @tags_without_section = @lesson.tags_without_section
     return unless @lesson.sections.count == 1 && @tags_without_section.any?
+
     section = @lesson.sections.first
     section.tags << @tags_without_section
   end
@@ -69,28 +71,31 @@ def destroy
 
   private
 
-  def set_lesson
-    @lesson = Lesson.find_by_id(params[:id])
-    return if @lesson.present?
-    redirect_to :root, alert: I18n.t('controllers.no_lesson')
-  end
+    def set_lesson
+      @lesson = Lesson.find_by_id(params[:id])
+      return if @lesson.present?
 
-  def lesson_params
-    params.require(:lesson).permit(:date, :lecture_id, :start_destination,
-                                   :end_destination, :details,
-                                   section_ids: [],
-                                   tag_ids: [])
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_lesson')
+    end
 
-  def update_media_order
-    media_order_from_json = JSON.parse(params[:lesson][:media_order])
-    return unless media_order_from_json.is_a?(Array)
-    media_order = media_order_from_json.map(&:to_i) - [0]
-    return unless media_order.sort == @lesson.media.pluck(:id).sort
-    Medium.acts_as_list_no_update do
-      @lesson.media.each do |m|
-        m.update(position: media_order.index(m.id))
+    def lesson_params
+      params.require(:lesson).permit(:date, :lecture_id, :start_destination,
+                                     :end_destination, :details,
+                                     section_ids: [],
+                                     tag_ids: [])
+    end
+
+    def update_media_order
+      media_order_from_json = JSON.parse(params[:lesson][:media_order])
+      return unless media_order_from_json.is_a?(Array)
+
+      media_order = media_order_from_json.map(&:to_i) - [0]
+      return unless media_order.sort == @lesson.media.pluck(:id).sort
+
+      Medium.acts_as_list_no_update do
+        @lesson.media.each do |m|
+          m.update(position: media_order.index(m.id))
+        end
       end
     end
-  end
 end
diff --git a/app/controllers/main_controller.rb b/app/controllers/main_controller.rb
index d1769a925..2d8653eae 100644
--- a/app/controllers/main_controller.rb
+++ b/app/controllers/main_controller.rb
@@ -1,6 +1,5 @@
 # MainController
 class MainController < ApplicationController
-
   before_action :check_for_consent
   authorize_resource class: false, only: :start
   layout 'application_no_sidebar'
@@ -34,7 +33,7 @@ def comments
     @media_comments.select! do |m|
       (Reader.find_by(user: current_user, thread: m[:thread])
             &.updated_at || (Time.now - 1000.years)) < m[:latest_comment].created_at &&
-      m[:medium].visible_for_user?(current_user)
+        m[:medium].visible_for_user?(current_user)
     end
     @media_array = Kaminari.paginate_array(@media_comments)
                            .page(params[:page]).per(10)
@@ -52,15 +51,16 @@ def start
     @talks = current_user.talks.includes(lecture: :term)
                          .select { |t| t.visible_for_user?(current_user) }
                          .sort_by do |t|
-                            [-t.lecture.term.begin_date.jd,
-                             t.position]
+                           [-t.lecture.term.begin_date.jd,
+                            t.position]
                          end
   end
 
   private
 
-  def check_for_consent
-    return unless user_signed_in?
-    redirect_to consent_profile_path unless current_user.consents
-  end
+    def check_for_consent
+      return unless user_signed_in?
+
+      redirect_to consent_profile_path unless current_user.consents
+    end
 end
diff --git a/app/controllers/media_controller.rb b/app/controllers/media_controller.rb
index a9082d3e6..f3e5678c5 100644
--- a/app/controllers/media_controller.rb
+++ b/app/controllers/media_controller.rb
@@ -65,6 +65,7 @@ def update
     @medium.update(medium_params)
     @errors = @medium.errors
     return unless @errors.empty?
+
     # make sure the medium is touched
     # (it will not be touched automatically in some cases (e.g. if you only
     # update the associated tags), causing trouble for caching)
@@ -93,13 +94,13 @@ def update
       # refreshed_video = @medium.video
       # @medium.update(video_data: refreshed_video.to_json)
     end
-    if @medium.sort == 'Quiz' &&params[:medium][:create_quiz_graph] == '1'
+    if @medium.sort == 'Quiz' && params[:medium][:create_quiz_graph] == '1'
       @medium.becomes(Quiz).update(level: 1,
                                    quiz_graph: QuizGraph.new(vertices: {},
-                                               edges: {},
-                                               root: 0,
-                                               default_table: {},
-                                               hide_solution: []))
+                                                             edges: {},
+                                                             root: 0,
+                                                             default_table: {},
+                                                             hide_solution: []))
     end
     # if changes to the manuscript have been made,
     # remove items that correspond to named destinations that no longer
@@ -123,6 +124,7 @@ def update
     end
     @tags_without_section = []
     return unless @medium.teachable.class.to_s == 'Lesson'
+
     add_tags_in_lesson_and_sections
   end
 
@@ -154,11 +156,11 @@ def create
       end
       if @medium.sort == 'Quiz'
         @medium.update(type: 'Quiz')
-        @medium.update(quiz_graph:QuizGraph.new(vertices: {},
-                                                edges: {},
-                                                root: 0,
-                                                default_table: {},
-                                                hide_solution: []),
+        @medium.update(quiz_graph: QuizGraph.new(vertices: {},
+                                                 edges: {},
+                                                 root: 0,
+                                                 default_table: {},
+                                                 hide_solution: []),
                        level: 1)
       end
       redirect_to edit_medium_path(@medium)
@@ -172,6 +174,7 @@ def publish
     publisher = MediumPublisher.parse(@medium, current_user, publish_params)
     @errors = publisher.errors
     return if @errors.present?
+
     @medium.update(publisher: publisher)
     if publisher.release_now
       @medium.publish!
@@ -217,14 +220,15 @@ def search
       filter_media = true
       params["search"]["access"] = 'irrelevant'
     end
-    params["search"]["answers_count"] = 'irrelevant' if search_params[:answers_count].blank?
+    params["search"]["answers_count"] =
+      'irrelevant' if search_params[:answers_count].blank?
 
     search = Medium.search_by(search_params, params[:page])
     search.execute
     results = search.results
     @total = search.total
 
-    # in the case of a search with tag_operator 'or', we 
+    # in the case of a search with tag_operator 'or', we
     # execute two searches and merge the results, where media
     # with the selected tags are now shown at the front of the list
     if search_params[:tag_operator] == "or" and search_params[:all_tags] == "0" and search_params[:fulltext].size >= 2
@@ -304,7 +308,7 @@ def add_item
     @item = Item.new(medium: @medium,
                      start_time: TimeStamp.new(total_seconds: @time))
     if @medium.sort == 'Kaviar' &&
-        @medium.teachable_type.in?(['Lesson', 'Lecture'])
+       @medium.teachable_type.in?(['Lesson', 'Lecture'])
       @item.section = @medium.teachable&.sections&.first
     end
   end
@@ -341,6 +345,7 @@ def add_screenshot
   # remove the video's screenshot
   def remove_screenshot
     return if @medium.screenshot.nil?
+
     @medium.update(screenshot: nil)
   end
 
@@ -376,7 +381,7 @@ def fill_teachable_select
     result = (Course.editable_selection(current_user) +
                 Lecture.editable_selection(current_user) +
                 Lesson.editable_selection(current_user))
-               .map { |t| { value: t[1], text: t[0] } }
+             .map { |t| { value: t[1], text: t[0] } }
     render json: result
   end
 
@@ -402,22 +407,36 @@ def get_statistics
     medium_consumption = Consumption.where(medium_id: @medium.id)
     if @medium.video.present?
       @video_downloads = medium_consumption.where(sort: 'video',
-                                                  mode: 'download').pluck(:created_at).map(&:to_date).tally.map{|k,t| {x: k,y:t}}.to_json
+                                                  mode: 'download').pluck(:created_at).map(&:to_date).tally.map { |k, t|
+        {
+          x: k, y: t
+        }
+      }.to_json
       @video_downloads_count = medium_consumption.where(sort: 'video',
-                                                  mode: 'download').count
+                                                        mode: 'download').count
       @video_thyme = medium_consumption.where(sort: 'video',
-                                              mode: 'thyme').pluck(:created_at).map(&:to_date).tally.map{|k,t| {x: k,y:t}}.to_json
+                                              mode: 'thyme').pluck(:created_at).map(&:to_date).tally.map { |k, t|
+        {
+          x: k, y: t
+        }
+      }.to_json
       @video_thyme_count = medium_consumption.where(sort: 'video',
                                                     mode: 'thyme').count
     end
     if @medium.manuscript.present?
-      @manuscript_access = medium_consumption.where(sort: 'manuscript').pluck(:created_at).map(&:to_date).tally.map{|k,t| {x: k,y:t}}.to_json
+      @manuscript_access = medium_consumption.where(sort: 'manuscript').pluck(:created_at).map(&:to_date).tally.map { |k, t|
+        { x: k, y: t }
+      }.to_json
       @manuscript_access_count = medium_consumption.where(sort: 'manuscript').count
     end
     if @medium.sort == 'Quiz'
 
-      @quiz_plays = medium_consumption.where(sort: 'quiz', mode: 'browser').pluck(:created_at).map(&:to_date).tally.map{|k,t| {x: k,y:t}}.to_json
-      @quiz_plays_count = medium_consumption.where(sort: 'quiz', mode: 'browser').count
+      @quiz_plays = medium_consumption.where(sort: 'quiz',
+                                             mode: 'browser').pluck(:created_at).map(&:to_date).tally.map { |k, t|
+        { x: k, y: t }
+      }.to_json
+      @quiz_plays_count = medium_consumption.where(sort: 'quiz',
+                                                   mode: 'browser').count
       @quiz_finished_count = Probe.finished_quizzes(@medium)
       @global_success = Probe.global_success_in_quiz(@medium.becomes(Quiz))
       @global_success_details = Probe.global_success_details(@medium.becomes(Quiz))
@@ -498,201 +517,205 @@ def fill_reassign_modal
 
   private
 
-  def medium_params
-    params.require(:medium).permit(:sort, :description, :video, :manuscript,
-                                   :external_reference_link,
-                                   :external_link_description,
-                                   :geogebra, :geogebra_app_name,
-                                   :teachable_type, :teachable_id,
-                                   :released, :text, :locale,
-                                   :content, :boost,
-                                   editor_ids: [],
-                                   tag_ids: [],
-                                   linked_medium_ids: [])
-  end
-
-  def publish_params
-    params.require(:medium).permit(:release_now, :released, :release_date,
-                                   :lock_comments, :publish_vertices,
-                                   :create_assignment, :assignment_title,
-                                   :assignment_deadline, :assignment_file_type,
-                                   :assignment_deletion_date)
-  end
-
-  def set_medium
-    @medium = Medium.find_by_id(params[:id])&.becomes(Medium)
-    return if @medium.present? && @medium.sort != 'RandomQuiz'
-    redirect_to :root, alert: I18n.t('controllers.no_medium')
-  end
-
-  def set_lecture
-    @lecture = Lecture.find_by_id(params[:id])
-    # store current lecture in cookie
-    if @lecture
-      cookies[:current_lecture_id] = @lecture.id
-      return
+    def medium_params
+      params.require(:medium).permit(:sort, :description, :video, :manuscript,
+                                     :external_reference_link,
+                                     :external_link_description,
+                                     :geogebra, :geogebra_app_name,
+                                     :teachable_type, :teachable_id,
+                                     :released, :text, :locale,
+                                     :content, :boost,
+                                     editor_ids: [],
+                                     tag_ids: [],
+                                     linked_medium_ids: [])
+    end
+
+    def publish_params
+      params.require(:medium).permit(:release_now, :released, :release_date,
+                                     :lock_comments, :publish_vertices,
+                                     :create_assignment, :assignment_title,
+                                     :assignment_deadline, :assignment_file_type,
+                                     :assignment_deletion_date)
+    end
+
+    def set_medium
+      @medium = Medium.find_by_id(params[:id])&.becomes(Medium)
+      return if @medium.present? && @medium.sort != 'RandomQuiz'
+
+      redirect_to :root, alert: I18n.t('controllers.no_medium')
+    end
+
+    def set_lecture
+      @lecture = Lecture.find_by_id(params[:id])
+      # store current lecture in cookie
+      if @lecture
+        cookies[:current_lecture_id] = @lecture.id
+        return
+      end
+      redirect_to :root, alert: I18n.t('controllers.no_lecture')
+    end
+
+    def set_teachable
+      if params[:teachable_type].in?(['Course', 'Lecture', 'Lesson', 'Talk']) &&
+         params[:teachable_id].present?
+        @teachable = params[:teachable_type].constantize
+                                            .find_by_id(params[:teachable_id])
+      end
+    end
+
+    def detach_components
+      if params[:medium][:detach_video] == 'true'
+        @medium.update(video: nil)
+        @medium.update(screenshot: nil)
+      end
+      if params[:medium][:detach_geogebra] == 'true' || @medium.sort != 'Sesam'
+        @medium.update(geogebra: nil)
+      end
+      return unless params[:medium][:detach_manuscript] == 'true'
+
+      @medium.update(manuscript: nil)
+    end
+
+    def sanitize_params
+      reveal_contradictions
+      sanitize_page!
+      sanitize_per!
+      params[:all] = (params[:all] == 'true') || (cookies[:all] == 'true')
+      cookies[:all] = params[:all]
+      cookies[:per] = false if cookies[:all]
+      params[:reverse] = params[:reverse] == 'true'
+    end
+
+    def check_for_consent
+      redirect_to consent_profile_path unless current_user.consents
     end
-    redirect_to :root, alert: I18n.t('controllers.no_lecture')
-  end
-
-  def set_teachable
-    if params[:teachable_type].in?(['Course', 'Lecture', 'Lesson', 'Talk']) &&
-       params[:teachable_id].present?
-      @teachable = params[:teachable_type].constantize
-                                          .find_by_id(params[:teachable_id])
-    end
-  end
-
-  def detach_components
-    if params[:medium][:detach_video] == 'true'
-      @medium.update(video: nil)
-      @medium.update(screenshot: nil)
-    end
-    if params[:medium][:detach_geogebra] == 'true' || @medium.sort != 'Sesam'
-      @medium.update(geogebra: nil)
-    end
-    return unless params[:medium][:detach_manuscript] == 'true'
-    @medium.update(manuscript: nil)
-  end
-
-  def sanitize_params
-    reveal_contradictions
-    sanitize_page!
-    sanitize_per!
-    params[:all] = (params[:all] == 'true') || (cookies[:all] == 'true')
-    cookies[:all] = params[:all]
-    cookies[:per] = false if cookies[:all]
-    params[:reverse] = params[:reverse] == 'true'
-  end
-
-  def check_for_consent
-    redirect_to consent_profile_path unless current_user.consents
-  end
-
-  # paginate results obtained by the search_results method
-  def paginated_results
-    if params[:all]
-      total_count = search_results.count
-      # without the total count parameter, kaminary will consider only only the
-      # first 25 entries
-      return Kaminari.paginate_array(search_results,
-                                     total_count: total_count + 1)
-    end
-    Kaminari.paginate_array(search_results).page(params[:page])
-            .per(params[:per])
-  end
-
-  # search is done in search class method for Medium
-  def search_results
-    search_results = Medium.search_all(params)
-    # search_results are ordered in a certain way
-    # the next lines ensure that filtering for visible media does not
-    # mess up the ordering
-    search_arel = Medium.where(id: search_results.pluck(:id))
-    visible_search_results = current_user.filter_visible_media(search_arel)
-    search_results &= visible_search_results
-    total = search_results.size
-    @lecture = Lecture.find_by_id(params[:id])
-    # filter out stuff from course level for generic users
-    if params[:visibility] == 'lecture'
-      search_results.reject! { |m| m.teachable_type == 'Course' }
-      # yields only lecture media and course media
-    elsif params[:visibility] == 'all'
-      # yields all lecture media and course media
-    else
-      # this is the default setting: 'thematic' selection of media
-      # yields all lecture media and course media whose tags have
-      # already been dealt with in the lecture
-      unless current_user.admin || @lecture.edited_by?(current_user)
-        lecture_tags = @lecture.tags_including_media_tags
-        search_results.reject! do |m|
-          m.teachable_type == 'Course' && (m.tags & lecture_tags).blank?
+
+    # paginate results obtained by the search_results method
+    def paginated_results
+      if params[:all]
+        total_count = search_results.count
+        # without the total count parameter, kaminary will consider only only the
+        # first 25 entries
+        return Kaminari.paginate_array(search_results,
+                                       total_count: total_count + 1)
+      end
+      Kaminari.paginate_array(search_results).page(params[:page])
+              .per(params[:per])
+    end
+
+    # search is done in search class method for Medium
+    def search_results
+      search_results = Medium.search_all(params)
+      # search_results are ordered in a certain way
+      # the next lines ensure that filtering for visible media does not
+      # mess up the ordering
+      search_arel = Medium.where(id: search_results.pluck(:id))
+      visible_search_results = current_user.filter_visible_media(search_arel)
+      search_results &= visible_search_results
+      total = search_results.size
+      @lecture = Lecture.find_by_id(params[:id])
+      # filter out stuff from course level for generic users
+      if params[:visibility] == 'lecture'
+        search_results.reject! { |m| m.teachable_type == 'Course' }
+        # yields only lecture media and course media
+      elsif params[:visibility] == 'all'
+        # yields all lecture media and course media
+      else
+        # this is the default setting: 'thematic' selection of media
+        # yields all lecture media and course media whose tags have
+        # already been dealt with in the lecture
+        unless current_user.admin || @lecture.edited_by?(current_user)
+          lecture_tags = @lecture.tags_including_media_tags
+          search_results.reject! do |m|
+            m.teachable_type == 'Course' && (m.tags & lecture_tags).blank?
+          end
         end
       end
+      sort = params[:project] == 'keks' ? 'Quiz' : params[:project]&.capitalize
+      search_results += @lecture.imported_media
+                                .where(sort: sort)
+                                .locally_visible
+      search_results.uniq!
+      @hidden = search_results.empty? && total.positive?
+      return search_results unless params[:reverse]
+
+      search_results.reverse
     end
-    sort = params[:project] == 'keks' ? 'Quiz' : params[:project]&.capitalize
-    search_results +=  @lecture.imported_media
-                               .where(sort: sort)
-                               .locally_visible
-    search_results.uniq!
-    @hidden = search_results.empty? && total.positive?
-    return search_results unless params[:reverse]
-    search_results.reverse
-  end
-
-  def reveal_contradictions
-    return unless params[:lecture_id].present?
-    return if params[:lecture_id].to_i.in?(@course.lecture_ids)
-    redirect_to :root, alert: I18n.t('controllers.contradiction')
-  end
-
-  def sanitize_page!
-    params[:page] = params[:page].to_i.positive? ? params[:page].to_i : 1
-  end
-
-  def sanitize_per!
-    if params[:per] || cookies[:per].to_i.positive?
-      cookies[:all] = 'false'
-    end
-    params[:per] = if params[:per].to_i.in?([3, 4, 8, 12, 24, 48])
-                     params[:per].to_i
-                   elsif cookies[:per].to_i.positive?
-                     cookies[:per].to_i
-                   else
-                     8
-                   end
-    cookies[:per] = params[:per]
-  end
-
-  def search_params
-    types = params[:search][:types] || []
-    types = [types] if types && !types.kind_of?(Array)
-    types -= [''] if types
-    types = nil if types == []
-    params[:search][:types] = types
-    params[:search][:user_id] = current_user.id
-    params.require(:search)
-          .permit(:all_types, :all_teachables, :all_tags,
-                  :all_editors, :tag_operator, :quiz, :access,
-                  :teachable_inheritance, :fulltext, :per,
-                  :clicker, :purpose, :answers_count,
-                  :results_as_list, :all_terms, :all_teachers,
-                  :lecture_option, :user_id,
-                  types: [],
-                  teachable_ids: [],
-                  tag_ids: [],
-                  editor_ids: [],
-                  term_ids: [],
-                  teacher_ids: [],
-                  media_lectures: [])
-          #.with_defaults(access: 'all')
-  end
-
-  # destroy all notifications related to this medium
-  def destroy_notifications
-    Notification.where(notifiable_id: @medium.id, notifiable_type: 'Medium')
-                .delete_all
-  end
-
-  def add_tags_in_lesson_and_sections
-    @tags_outside_lesson = @medium.tags_outside_lesson
-    if @tags_outside_lesson
-      @medium.teachable.tags << @tags_outside_lesson
-      @tags_without_section = @tags_outside_lesson & @medium.teachable.tags_without_section
-      if @medium.teachable.sections.count == 1
-        section = @medium.teachable.sections.first
-        section.tags << @tags_without_section
+
+    def reveal_contradictions
+      return unless params[:lecture_id].present?
+      return if params[:lecture_id].to_i.in?(@course.lecture_ids)
+
+      redirect_to :root, alert: I18n.t('controllers.contradiction')
+    end
+
+    def sanitize_page!
+      params[:page] = params[:page].to_i.positive? ? params[:page].to_i : 1
+    end
+
+    def sanitize_per!
+      if params[:per] || cookies[:per].to_i.positive?
+        cookies[:all] = 'false'
       end
+      params[:per] = if params[:per].to_i.in?([3, 4, 8, 12, 24, 48])
+        params[:per].to_i
+      elsif cookies[:per].to_i.positive?
+        cookies[:per].to_i
+      else
+        8
+      end
+      cookies[:per] = params[:per]
+    end
+
+    def search_params
+      types = params[:search][:types] || []
+      types = [types] if types && !types.kind_of?(Array)
+      types -= [''] if types
+      types = nil if types == []
+      params[:search][:types] = types
+      params[:search][:user_id] = current_user.id
+      params.require(:search)
+            .permit(:all_types, :all_teachables, :all_tags,
+                    :all_editors, :tag_operator, :quiz, :access,
+                    :teachable_inheritance, :fulltext, :per,
+                    :clicker, :purpose, :answers_count,
+                    :results_as_list, :all_terms, :all_teachers,
+                    :lecture_option, :user_id,
+                    types: [],
+                    teachable_ids: [],
+                    tag_ids: [],
+                    editor_ids: [],
+                    term_ids: [],
+                    teacher_ids: [],
+                    media_lectures: [])
+      # .with_defaults(access: 'all')
     end
-  end
 
-  def store_access
-    mode = action_name == 'play' ? 'thyme' : 'pdf_view'
-    sort = action_name == 'play' ? 'video' : 'manuscript'
-    ConsumptionSaver.perform_async(@medium.id, mode, sort)
-  end
+    # destroy all notifications related to this medium
+    def destroy_notifications
+      Notification.where(notifiable_id: @medium.id, notifiable_type: 'Medium')
+                  .delete_all
+    end
+
+    def add_tags_in_lesson_and_sections
+      @tags_outside_lesson = @medium.tags_outside_lesson
+      if @tags_outside_lesson
+        @medium.teachable.tags << @tags_outside_lesson
+        @tags_without_section = @tags_outside_lesson & @medium.teachable.tags_without_section
+        if @medium.teachable.sections.count == 1
+          section = @medium.teachable.sections.first
+          section.tags << @tags_without_section
+        end
+      end
+    end
 
-  def store_download
-    ConsumptionSaver.perform_async(@medium.id, 'download', params[:sort])
-  end
+    def store_access
+      mode = action_name == 'play' ? 'thyme' : 'pdf_view'
+      sort = action_name == 'play' ? 'video' : 'manuscript'
+      ConsumptionSaver.perform_async(@medium.id, mode, sort)
+    end
+
+    def store_download
+      ConsumptionSaver.perform_async(@medium.id, 'download', params[:sort])
+    end
 end
diff --git a/app/controllers/notifications_controller.rb b/app/controllers/notifications_controller.rb
index b65fda5dc..a43809799 100644
--- a/app/controllers/notifications_controller.rb
+++ b/app/controllers/notifications_controller.rb
@@ -29,6 +29,7 @@ def destroy_all
   def destroy_lecture_notifications
     lecture = Lecture.find_by_id(params[:lecture_id])
     return unless lecture.present?
+
     Notification.delete(current_user.active_notifications(lecture).pluck(:id))
     current_user.touch
     render :destroy_all
@@ -44,9 +45,10 @@ def destroy_news_notifications
 
   private
 
-  def set_notification
-    @notification = Notification.find_by_id(params[:id])
-    return if @notification.present?
-    redirect_to :root, alert: I18n.t('controllers.no_notification')
-  end
+    def set_notification
+      @notification = Notification.find_by_id(params[:id])
+      return if @notification.present?
+
+      redirect_to :root, alert: I18n.t('controllers.no_notification')
+    end
 end
diff --git a/app/controllers/profile_controller.rb b/app/controllers/profile_controller.rb
index 978a90447..d74eeb08a 100644
--- a/app/controllers/profile_controller.rb
+++ b/app/controllers/profile_controller.rb
@@ -24,6 +24,7 @@ def edit
   def update
     check_passphrases
     return if @errors.present?
+
     if @user.update(lectures: @lectures,
                     name: @name,
                     name_in_tutorials: @name_in_tutorials,
@@ -51,6 +52,7 @@ def check_for_consent
       return
     end
     return unless @user.consents
+
     redirect_to edit_profile_path,
                 notice: t('profile.please_update')
   end
@@ -69,20 +71,21 @@ def toggle_thread_subscription
       else
         @thread.unsubscribe(@user)
       end
-      @result =  !!@thread.subscription_for(@user)
+      @result = !!@thread.subscription_for(@user)
     end
   end
 
   def subscribe_lecture
     @success = false
     if !@lecture.published? && !current_user.admin &&
-      !@lecture.edited_by?(current_user)
+       !@lecture.edited_by?(current_user)
       @unpublished = true
       return
     end
     return if @lecture.passphrase.present? &&
-                !@lecture.in?(current_user.lectures) &&
-                @lecture.passphrase != @passphrase
+              !@lecture.in?(current_user.lectures) &&
+              @lecture.passphrase != @passphrase
+
     @success = current_user.subscribe_lecture!(@lecture)
 
     redirect_to lecture_path(@lecture) if @parent == "redirect"
@@ -91,14 +94,15 @@ def subscribe_lecture
   def unsubscribe_lecture
     @success = current_user.unsubscribe_lecture!(@lecture)
     @none_left = case @parent
-      when 'current_subscribed' then current_user.current_subscribed_lectures
-                                                 .empty?
-      when 'inactive' then current_user.inactive_lectures.empty?
+                 when 'current_subscribed' then current_user.current_subscribed_lectures
+                                                            .empty?
+                 when 'inactive' then current_user.inactive_lectures.empty?
     end
   end
 
   def star_lecture
     return unless @lecture&.in?(current_user.lectures)
+
     if !@lecture.in?(current_user.favorite_lectures)
       current_user.favorite_lectures << @lecture
     end
@@ -111,6 +115,7 @@ def star_lecture
 
   def unstar_lecture
     return unless @lecture
+
     current_user.favorite_lectures.delete(@lecture)
     current_user.touch
   end
@@ -118,12 +123,13 @@ def unstar_lecture
   def show_accordion
     @collapse_id = params[:id]
     redirect_to :root and return unless @collapse_id.present?
+
     @lectures = case @collapse_id
-      when 'collapseCurrentStuff' then current_user.current_subscribed_lectures
-      when 'collapseInactiveLectures' then current_user.inactive_lectures
-                                                       .includes(:course, :term)
-                                                       .sort
-      when 'collapseAllCurrent' then current_user.current_subscribable_lectures
+                when 'collapseCurrentStuff' then current_user.current_subscribed_lectures
+                when 'collapseInactiveLectures' then current_user.inactive_lectures
+                                                                 .includes(:course, :term)
+                                                                 .sort
+                when 'collapseAllCurrent' then current_user.current_subscribable_lectures
     end
     @link = @collapse_id.remove('collapse').camelize(:lower) + 'Link'
   end
@@ -136,81 +142,81 @@ def request_data
 
   private
 
-  def set_user
-    @user = current_user
-  end
+    def set_user
+      @user = current_user
+    end
 
-  def set_basics
-    @subscription_type = params[:user][:subscription_type].to_i
-    @name = params[:user][:name]
-    @name_in_tutorials = params[:user][:name_in_tutorials]
-    @lectures = Lecture.where(id: lecture_ids)
-    @courses = Course.where(id: @lectures.pluck(:course_id).uniq)
-    @locale = params[:user][:locale]
-  end
+    def set_basics
+      @subscription_type = params[:user][:subscription_type].to_i
+      @name = params[:user][:name]
+      @name_in_tutorials = params[:user][:name_in_tutorials]
+      @lectures = Lecture.where(id: lecture_ids)
+      @courses = Course.where(id: @lectures.pluck(:course_id).uniq)
+      @locale = params[:user][:locale]
+    end
 
-  def email_params
-    params.require(:user).permit(:email_for_medium, :email_for_announcement,
-                                 :email_for_teachable, :email_for_news,
-                                 :email_for_submission_upload,
-                                 :email_for_submission_removal,
-                                 :email_for_submission_join,
-                                 :email_for_submission_leave,
-                                 :email_for_correction_upload,
-                                 :email_for_submission_decision)
-  end
+    def email_params
+      params.require(:user).permit(:email_for_medium, :email_for_announcement,
+                                   :email_for_teachable, :email_for_news,
+                                   :email_for_submission_upload,
+                                   :email_for_submission_removal,
+                                   :email_for_submission_join,
+                                   :email_for_submission_leave,
+                                   :email_for_correction_upload,
+                                   :email_for_submission_decision)
+    end
 
-  def set_lecture
-    @lecture = Lecture.find_by_id(lecture_params[:id])
-    @passphrase = lecture_params[:passphrase]
-    @parent = lecture_params[:parent]
-    @current = !@parent.in?(['lectureSearch', 'inactive'])
-    redirect_to start_path unless @lecture
-  end
+    def set_lecture
+      @lecture = Lecture.find_by_id(lecture_params[:id])
+      @passphrase = lecture_params[:passphrase]
+      @parent = lecture_params[:parent]
+      @current = !@parent.in?(['lectureSearch', 'inactive'])
+      redirect_to start_path unless @lecture
+    end
 
-  def lecture_params
-    params.require(:lecture).permit(:id, :passphrase, :parent)
-  end
+    def lecture_params
+      params.require(:lecture).permit(:id, :passphrase, :parent)
+    end
 
-  # extracts all lecture ids from user params
-  def lecture_ids
-    params[:user][:lecture].select { |k, v| v == '1' }.keys.map(&:to_i)
-  end
+    # extracts all lecture ids from user params
+    def lecture_ids
+      params[:user][:lecture].select { |k, v| v == '1' }.keys.map(&:to_i)
+    end
 
-  def clean_up_notifications
-    # delete all of the user's notifications if he does not want them
-    # remove all notification related not related to subscribed courses
-    # or lectures
-    subscribed_teachables = @courses + @lectures
-    irrelevant_notifications = @user.notifications.select do |n|
-      n.teachable.present? && !n.teachable.in?(subscribed_teachables)
+    def clean_up_notifications
+      # delete all of the user's notifications if he does not want them
+      # remove all notification related not related to subscribed courses
+      # or lectures
+      subscribed_teachables = @courses + @lectures
+      irrelevant_notifications = @user.notifications.select do |n|
+        n.teachable.present? && !n.teachable.in?(subscribed_teachables)
+      end
+      Notification.where(id: irrelevant_notifications.map(&:id)).delete_all
     end
-    Notification.where(id: irrelevant_notifications.map(&:id)).delete_all
-  end
 
-  # if user unsubscribed the lecture the current lecture cookie refers to,
-  # set the lectures cookie to nil
-  def update_lecture_cookie
-    unless @current_lecture.in?(@user.lectures)
-      cookies[:current_lecture_id] = nil
+    # if user unsubscribed the lecture the current lecture cookie refers to,
+    # set the lectures cookie to nil
+    def update_lecture_cookie
+      unless @current_lecture.in?(@user.lectures)
+        cookies[:current_lecture_id] = nil
+      end
     end
-  end
 
-  # stop the update if any of passphrases for newly subscribed
-  # lectures is incorrect
-  def check_passphrases
-    @errors = {}
-    restricted_lectures = Lecture.where(id: lecture_ids)
-                                    .select do |l|
-                                      l.in?(l.course
-                                             .to_be_authorized_lectures(current_user))
-                                    end
-    restricted_lectures.each do |l|
-      given_passphrase = params[:user][:pass_lecture][l.id.to_s]
-      unless given_passphrase == l.passphrase
-        @errors[:passphrase] ||= []
-        @errors[:passphrase].push l.id
+    # stop the update if any of passphrases for newly subscribed
+    # lectures is incorrect
+    def check_passphrases
+      @errors = {}
+      restricted_lectures = Lecture.where(id: lecture_ids)
+                                   .select do |l|
+        l.in?(l.course
+               .to_be_authorized_lectures(current_user))
+      end
+      restricted_lectures.each do |l|
+        given_passphrase = params[:user][:pass_lecture][l.id.to_s]
+        unless given_passphrase == l.passphrase
+          @errors[:passphrase] ||= []
+          @errors[:passphrase].push l.id
+        end
       end
     end
-  end
 end
diff --git a/app/controllers/programs_controller.rb b/app/controllers/programs_controller.rb
index 096e082fb..babb0eb30 100644
--- a/app/controllers/programs_controller.rb
+++ b/app/controllers/programs_controller.rb
@@ -3,47 +3,46 @@ class ProgramsController < ApplicationController
   before_action :set_program, except: [:new, :create]
   authorize_resource except: [:new, :create]
 
-
   def current_ability
     @current_ability ||= ProgramAbility.new(current_user)
   end
 
-	def edit
-	end
+  def edit
+  end
 
-	def new
-		@program = Program.new(subject_id: params[:subject_id].to_i)
+  def new
+    @program = Program.new(subject_id: params[:subject_id].to_i)
     authorize! :new, @program
-	end
+  end
 
-	def update
-		@program.update(program_params)
-		redirect_to classification_path
-	end
+  def update
+    @program.update(program_params)
+    redirect_to classification_path
+  end
 
-	def create
-		@program = Program.new(program_params)
-		@program.subject_id = params[:program][:subject_id].to_i
+  def create
+    @program = Program.new(program_params)
+    @program.subject_id = params[:program][:subject_id].to_i
     authorize! :create, @program
-		@program.save
-		redirect_to classification_path
-	end
+    @program.save
+    redirect_to classification_path
+  end
 
-	def destroy
-		@program.destroy
-		redirect_to classification_path
-	end
+  def destroy
+    @program.destroy
+    redirect_to classification_path
+  end
 
   private
 
-  def set_program
-    @program = Program.find_by_id(params[:id])
-    return if @program.present?
+    def set_program
+      @program = Program.find_by_id(params[:id])
+      return if @program.present?
 
-    redirect_to root_path, alert: I18n.t('controllers.no_program')
-  end
+      redirect_to root_path, alert: I18n.t('controllers.no_program')
+    end
 
-  def program_params
-  	params.require(:program).permit(*Program.globalize_attribute_names)
-  end
-end
\ No newline at end of file
+    def program_params
+      params.require(:program).permit(*Program.globalize_attribute_names)
+    end
+end
diff --git a/app/controllers/questions_controller.rb b/app/controllers/questions_controller.rb
index 7daaf3936..1444e3ba1 100644
--- a/app/controllers/questions_controller.rb
+++ b/app/controllers/questions_controller.rb
@@ -16,6 +16,7 @@ def edit
 
   def update
     return if @errors
+
     @success = true if @question.update(question_params)
     if question_params[:question_sort] == 'free'
       answer = @question.answers.first
@@ -53,14 +54,14 @@ def reassign
 
   def set_solution_type
     content = if params[:type] == 'MampfExpression'
-                MampfExpression.trivial_instance
-              elsif params[:type] == 'MampfMatrix'
-                MampfMatrix.trivial_instance
-              elsif params[:type] == 'MampfTuple'
-                MampfTuple.trivial_instance
-              elsif params[:type] == 'MampfSet'
-                MampfSet.trivial_instance
-              end
+      MampfExpression.trivial_instance
+    elsif params[:type] == 'MampfMatrix'
+      MampfMatrix.trivial_instance
+    elsif params[:type] == 'MampfTuple'
+      MampfTuple.trivial_instance
+    elsif params[:type] == 'MampfSet'
+      MampfSet.trivial_instance
+    end
     @solution = Solution.new(content)
   end
 
@@ -76,33 +77,37 @@ def render_question_parameters
 
   private
 
-  def set_question
-    @question = Question.find_by_id(params[:id])
-    return if @question.present?
-    redirect_to :root, alert: I18n.t('controllers.no_question')
-  end
+    def set_question
+      @question = Question.find_by_id(params[:id])
+      return if @question.present?
 
-  def set_quizzes
-    @quizzes = params[:question].select { |k, v| v == '1' && k.start_with?('quiz-') }
-                                .keys.map { |k| k.remove('quiz-').to_i }
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_question')
+    end
 
-  def check_solution_errors
-    return unless params[:question][:solution_error].present?
-    @errors = ActiveModel::Errors.new(@question)
-    @errors.add(:base, params[:question][:solution_error])
-  end
+    def set_quizzes
+      @quizzes = params[:question].select { |k, v|
+                   v == '1' && k.start_with?('quiz-')
+                 }
+                                  .keys.map { |k| k.remove('quiz-').to_i }
+    end
+
+    def check_solution_errors
+      return unless params[:question][:solution_error].present?
 
-  def question_params
-    result = params.require(:question)
-                   .permit(:label, :text, :type, :hint, :level,
-                           :question_sort, :independent, :vertex_id,
-                           :solution_type,
-                           solution_content: {})
-    if result[:solution_type] && result[:solution_content]
-      result[:solution] = Solution.from_hash(result[:solution_type],
-                                             result[:solution_content])
+      @errors = ActiveModel::Errors.new(@question)
+      @errors.add(:base, params[:question][:solution_error])
+    end
+
+    def question_params
+      result = params.require(:question)
+                     .permit(:label, :text, :type, :hint, :level,
+                             :question_sort, :independent, :vertex_id,
+                             :solution_type,
+                             solution_content: {})
+      if result[:solution_type] && result[:solution_content]
+        result[:solution] = Solution.from_hash(result[:solution_type],
+                                               result[:solution_content])
+      end
+      result.except(:solution_type, :solution_content)
     end
-    result.except(:solution_type, :solution_content)
-  end
 end
diff --git a/app/controllers/quiz_certificates_controller.rb b/app/controllers/quiz_certificates_controller.rb
index 572dca0a8..0f611e18d 100644
--- a/app/controllers/quiz_certificates_controller.rb
+++ b/app/controllers/quiz_certificates_controller.rb
@@ -22,31 +22,35 @@ def validate
 
   private
 
-  def set_certificate
-    @certificate = QuizCertificate.find_by_id(params[:id])
-    return if @certificate.present?
-    redirect_to :root, alert: I18n.t('controllers.no_certificate')
-  end
+    def set_certificate
+      @certificate = QuizCertificate.find_by_id(params[:id])
+      return if @certificate.present?
 
-  def check_if_claimed
-    return unless @certificate.user
-    redirect_to :root, alert: I18n.t('controllers.certificate_already_claimed')
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_certificate')
+    end
 
-  def certificate_params
-    params.permit(:code, :lecture_id)
-  end
+    def check_if_claimed
+      return unless @certificate.user
+
+      redirect_to :root,
+                  alert: I18n.t('controllers.certificate_already_claimed')
+    end
 
-  def set_locale_by_quiz
-    return unless @certificate
-    quiz_locale = @certificate.quiz.locale_with_inheritance
-    I18n.locale = quiz_locale || current_user.locale ||
+    def certificate_params
+      params.permit(:code, :lecture_id)
+    end
+
+    def set_locale_by_quiz
+      return unless @certificate
+
+      quiz_locale = @certificate.quiz.locale_with_inheritance
+      I18n.locale = quiz_locale || current_user.locale ||
                     I18n.default_locale
-  end
+    end
 
-  def set_locale_by_lecture
-    @lecture = Lecture.find_by_id(certificate_params[:lecture_id])
-    I18n.locale = @lecture&.locale_with_inheritance || current_user.locale ||
+    def set_locale_by_lecture
+      @lecture = Lecture.find_by_id(certificate_params[:lecture_id])
+      I18n.locale = @lecture&.locale_with_inheritance || current_user.locale ||
                     I18n.default_locale
-  end
-end
\ No newline at end of file
+    end
+end
diff --git a/app/controllers/quizzes_controller.rb b/app/controllers/quizzes_controller.rb
index 3e92d5c6c..3cf4ead9c 100644
--- a/app/controllers/quizzes_controller.rb
+++ b/app/controllers/quizzes_controller.rb
@@ -98,64 +98,69 @@ def render_vertex_quizzable
 
   private
 
-  def set_quiz
-    @quiz = Quiz.find_by_id(params[:id])
-    return if @quiz.present?
-    redirect_to :root, alert: I18n.t('controllers.no_quiz')
-  end
+    def set_quiz
+      @quiz = Quiz.find_by_id(params[:id])
+      return if @quiz.present?
 
-  def init_values
-    quiz_round_params = if params[:question].present? &&
-                          params[:question][:solution_type].present?
-                          params[:question]
-                        else
-                          params
-                        end
-    if user_signed_in? && current_user.study_participant
-      quiz_round_params[:study_participant] = current_user.anonymized_id
+      redirect_to :root, alert: I18n.t('controllers.no_quiz')
     end
-    quiz_round_params[:save_probe] =
-      if !user_signed_in?
-        true
-      elsif current_user.admin?
-        false
-      elsif current_user.in?(Quiz.find(params[:id]).editors_with_inheritance)
-        false
+
+    def init_values
+      quiz_round_params = if params[:question].present? &&
+                             params[:question][:solution_type].present?
+        params[:question]
       else
-        true
+        params
       end
-    @quiz_round = QuizRound.new(quiz_round_params)
-  end
+      if user_signed_in? && current_user.study_participant
+        quiz_round_params[:study_participant] = current_user.anonymized_id
+      end
+      quiz_round_params[:save_probe] =
+        if !user_signed_in?
+          true
+        elsif current_user.admin?
+          false
+        elsif current_user.in?(Quiz.find(params[:id]).editors_with_inheritance)
+          false
+        else
+          true
+        end
+      @quiz_round = QuizRound.new(quiz_round_params)
+    end
 
-  def quiz_params
-    params.require(:quiz).permit(:label, :root, :level, :id_js)
-  end
+    def quiz_params
+      params.require(:quiz).permit(:label, :root, :level, :id_js)
+    end
 
-  def check_accessibility
-    return if @quiz.sort == 'RandomQuiz'
-    return if user_signed_in? && @quiz.visible_for_user?(current_user)
-    return if !user_signed_in? && @quiz.free?
-    redirect_to :root, alert: I18n.t('controllers.no_quiz_access')
-  end
+    def check_accessibility
+      return if @quiz.sort == 'RandomQuiz'
+      return if user_signed_in? && @quiz.visible_for_user?(current_user)
+      return if !user_signed_in? && @quiz.free?
 
-  def check_vertex_accessibility
-    return if @quiz.sort == 'RandomQuiz'
-    if user_signed_in?
-      return if current_user.in?(@quiz.editors_with_inheritance)
-      return if current_user.admin
-      return if @quiz.quizzables_visible_for_user?(current_user)
+      redirect_to :root, alert: I18n.t('controllers.no_quiz_access')
     end
-    return if !user_signed_in? && @quiz.quizzables_free?
-    redirect_to :root, alert: I18n.t('controllers.no_quiz_vertex_access')
-  end
 
-  def check_errors
-    return if @quiz.sort == 'RandomQuiz'
-    return unless @quiz.find_errors&.any?
-    redirect_to :root, alert: I18n.t('controllers.quiz_has_error')
-  end
+    def check_vertex_accessibility
+      return if @quiz.sort == 'RandomQuiz'
 
-  def store_access
-    ConsumptionSaver.perform_async(@quiz.id, 'browser', 'quiz')
-  end
+      if user_signed_in?
+        return if current_user.in?(@quiz.editors_with_inheritance)
+        return if current_user.admin
+        return if @quiz.quizzables_visible_for_user?(current_user)
+      end
+      return if !user_signed_in? && @quiz.quizzables_free?
+
+      redirect_to :root, alert: I18n.t('controllers.no_quiz_vertex_access')
+    end
+
+    def check_errors
+      return if @quiz.sort == 'RandomQuiz'
+      return unless @quiz.find_errors&.any?
+
+      redirect_to :root, alert: I18n.t('controllers.quiz_has_error')
+    end
+
+    def store_access
+      ConsumptionSaver.perform_async(@quiz.id, 'browser', 'quiz')
+    end
 end
diff --git a/app/controllers/readers_controller.rb b/app/controllers/readers_controller.rb
index 6bd1587ab..362e5cd86 100644
--- a/app/controllers/readers_controller.rb
+++ b/app/controllers/readers_controller.rb
@@ -5,6 +5,7 @@ class ReadersController < ApplicationController
   def update
     @thread = Commontator::Thread.find_by_id(reader_params[:thread_id])
     return unless @thread
+
     @reader = Reader.find_or_create_by(user: current_user,
                                        thread: @thread)
     @reader.touch
@@ -32,7 +33,7 @@ def update_all
 
   private
 
-  def reader_params
-    params.permit(:thread_id)
-  end
-end
\ No newline at end of file
+    def reader_params
+      params.permit(:thread_id)
+    end
+end
diff --git a/app/controllers/referrals_controller.rb b/app/controllers/referrals_controller.rb
index c058bf57e..4d07fa221 100644
--- a/app/controllers/referrals_controller.rb
+++ b/app/controllers/referrals_controller.rb
@@ -15,6 +15,7 @@ def update
     # be affected; links are changed *globally*
     update_item if Item.find_by_id(@item_id)&.sort == 'link'
     return if @errors.present?
+
     @referral.update(updated_params)
     @errors = @referral.errors unless @referral.valid?
   end
@@ -25,12 +26,12 @@ def edit
     # otherwise load all items in the referral's item's medium scope
     # that the user can choose from in the item dropdown menu
     @item_selection = if @referral.item.sort == 'link'
-                        Item.where(medium: nil)
-                            .map { |i| [i.description, i.id] }
-                      else
-                        @referral.item.medium.teachable.media_scope
-                                 .media_items_with_inheritance
-                      end
+      Item.where(medium: nil)
+          .map { |i| [i.description, i.id] }
+    else
+      @referral.item.medium.teachable.media_scope
+               .media_items_with_inheritance
+    end
     @item = Item.new(sort: 'link')
   end
 
@@ -70,36 +71,36 @@ def list_items
 
   private
 
-  def set_referral
-    @referral = Referral.find(params[:id])
-  end
+    def set_referral
+      @referral = Referral.find(params[:id])
+    end
 
-  def set_basics
-    @item_id = params[:referral][:item_id].to_i
-  end
+    def set_basics
+      @item_id = params[:referral][:item_id].to_i
+    end
 
-  def referral_params
-    # clone referral params in order to convert start and end time to proper
-    # TimeStamp instances
-    filter = params.require(:referral).permit(:medium_id, :item_id, :start_time,
-                                              :end_time, :description, :link,
-                                              :explanation, :ref_id).clone
-    filter[:start_time] = TimeStamp.new(time_string: filter[:start_time])
-    filter[:end_time] = TimeStamp.new(time_string: filter[:end_time])
-    filter
-  end
+    def referral_params
+      # clone referral params in order to convert start and end time to proper
+      # TimeStamp instances
+      filter = params.require(:referral).permit(:medium_id, :item_id, :start_time,
+                                                :end_time, :description, :link,
+                                                :explanation, :ref_id).clone
+      filter[:start_time] = TimeStamp.new(time_string: filter[:start_time])
+      filter[:end_time] = TimeStamp.new(time_string: filter[:end_time])
+      filter
+    end
 
-  def update_item
-    item = Item.find(@item_id)
-    item.update(link: referral_params[:link],
-                description: referral_params[:description])
-    @errors = item.errors unless item.valid?
-  end
+    def update_item
+      item = Item.find(@item_id)
+      item.update(link: referral_params[:link],
+                  description: referral_params[:description])
+      @errors = item.errors unless item.valid?
+    end
 
-  def updated_params
-    { medium_id: referral_params[:medium_id], item_id: @item_id,
-      explanation: referral_params[:explanation],
-      start_time: referral_params[:start_time],
-      end_time: referral_params[:end_time] }
-  end
+    def updated_params
+      { medium_id: referral_params[:medium_id], item_id: @item_id,
+        explanation: referral_params[:explanation],
+        start_time: referral_params[:start_time],
+        end_time: referral_params[:end_time] }
+    end
 end
diff --git a/app/controllers/registrations_controller.rb b/app/controllers/registrations_controller.rb
index ec884e78d..0cd93ae14 100644
--- a/app/controllers/registrations_controller.rb
+++ b/app/controllers/registrations_controller.rb
@@ -7,10 +7,11 @@ class RegistrationsController < Devise::RegistrationsController
 
   def verify_captcha
     return true unless ENV['USE_CAPTCHA_SERVICE']
+
     begin
       uri = URI.parse(ENV['CAPTCHA_VERIFY_URL'])
-      data = { message:params["frc-captcha-solution"],
-               application_token:ENV['CAPTCHA_APPLICATION_TOKEN'] }
+      data = { message: params["frc-captcha-solution"],
+               application_token: ENV['CAPTCHA_APPLICATION_TOKEN'] }
       header = { 'Content-Type': 'text/json' }
       http = Net::HTTP.new(uri.host, uri.port)
       http.use_ssl = true if ENV['CAPTCHA_VERIFY_URL'].include?('https')
@@ -19,7 +20,7 @@ def verify_captcha
 
       # Send the request
       response = http.request(request)
-      answer =  JSON.parse(response.body)
+      answer = JSON.parse(response.body)
       return true if answer["message"] == "verified"
     rescue
     end
@@ -41,19 +42,25 @@ def destroy
     password_correct = resource.valid_password?(deletion_params[:password])
     if !password_correct
       set_flash_message :alert, :password_incorrect
-      respond_with_navigational(resource){ redirect_to after_sign_up_path_for(resource_name) }
+      respond_with_navigational(resource) {
+        redirect_to after_sign_up_path_for(resource_name)
+      }
       return
     end
     success = resource.archive_and_destroy(deletion_params[:archive_name])
     if !success
       set_flash_message :alert, :not_destroyed
-      respond_with_navigational(resource){ redirect_to after_sign_up_path_for(resource_name) }
+      respond_with_navigational(resource) {
+        redirect_to after_sign_up_path_for(resource_name)
+      }
       return
     end
     Devise.sign_out_all_scopes ? sign_out : sign_out(resource_name)
     set_flash_message :notice, :destroyed
     yield resource if block_given?
-    respond_with_navigational(resource){ redirect_to after_sign_out_path_for(resource_name) }
+    respond_with_navigational(resource) {
+      redirect_to after_sign_out_path_for(resource_name)
+    }
   end
 
   def after_sign_up_path_for(resource)
@@ -62,17 +69,17 @@ def after_sign_up_path_for(resource)
 
   private
 
-  def check_registration_limit
-    if User.where("users.confirmed_at is NULL and users.created_at > '#{(DateTime.now()-(ENV['MAMPF_REGISTRATION_TIMEFRAME']||15).to_i.minutes)}'").count > (ENV['MAMPF_MAX_REGISTRATION_PER_TIMEFRAME'] || 40).to_i
-      self.resource = resource_class.new devise_parameter_sanitizer.sanitize(:sign_up)
-      resource.validate # Look for any other validation errors besides reCAPTCHA
-      set_flash_message :alert, :too_many_registrations
-      set_minimum_password_length
-      respond_with_navigational(resource) { render :new }
+    def check_registration_limit
+      if User.where("users.confirmed_at is NULL and users.created_at > '#{(DateTime.now() - (ENV['MAMPF_REGISTRATION_TIMEFRAME'] || 15).to_i.minutes)}'").count > (ENV['MAMPF_MAX_REGISTRATION_PER_TIMEFRAME'] || 40).to_i
+        self.resource = resource_class.new devise_parameter_sanitizer.sanitize(:sign_up)
+        resource.validate # Look for any other validation errors besides reCAPTCHA
+        set_flash_message :alert, :too_many_registrations
+        set_minimum_password_length
+        respond_with_navigational(resource) { render :new }
+      end
     end
-  end
 
-  def deletion_params
-    params.permit(:archive_name, :password)
-  end
+    def deletion_params
+      params.permit(:archive_name, :password)
+    end
 end
diff --git a/app/controllers/remarks_controller.rb b/app/controllers/remarks_controller.rb
index c1529482b..9d95e9779 100644
--- a/app/controllers/remarks_controller.rb
+++ b/app/controllers/remarks_controller.rb
@@ -41,18 +41,19 @@ def cancel_remark_basics
 
   private
 
-  def set_remark
-    @remark = Remark.find_by_id(params[:id])
-    return if @remark.present?
-    redirect_to remarks_path, alert: I18n.t('controllers.no_remark')
-  end
+    def set_remark
+      @remark = Remark.find_by_id(params[:id])
+      return if @remark.present?
 
-  def set_quizzes
-    @quizzes = params[:remark].select { |_k, v| v == '1' }.keys
-                              .map { |k| k.remove('quiz-').to_i }
-  end
+      redirect_to remarks_path, alert: I18n.t('controllers.no_remark')
+    end
 
-  def remark_params
-    params.require(:remark).permit(:text, :text_input, :type)
-  end
+    def set_quizzes
+      @quizzes = params[:remark].select { |_k, v| v == '1' }.keys
+                                .map { |k| k.remove('quiz-').to_i }
+    end
+
+    def remark_params
+      params.require(:remark).permit(:text, :text_input, :type)
+    end
 end
diff --git a/app/controllers/search_controller.rb b/app/controllers/search_controller.rb
index 662b36536..ef9d49636 100644
--- a/app/controllers/search_controller.rb
+++ b/app/controllers/search_controller.rb
@@ -20,35 +20,37 @@ def index
     # (taking into account his preferences and subscribed courses)
     @filtered_tags = current_user.filter_tags(@tags)
     return unless @tags.empty?
+
     # determine tags whose title is apartial match
     find_similar_tags
   end
 
   private
 
-  def check_for_consent
-    redirect_to consent_profile_path unless current_user.consents
-  end
+    def check_for_consent
+      redirect_to consent_profile_path unless current_user.consents
+    end
 
-  def set_search_string
-    @search_string = params[:search]
-  end
+    def set_search_string
+      @search_string = params[:search]
+    end
+
+    # make sure the seacrh string is not blank and consists of at least
+    # two letters
+    def sanitize_search_string
+      if @search_string.nil?
+        redirect_back fallback_location: root_path,
+                      alert: I18n.t('controllers.no_search_term')
+        return
+      end
+      return if @search_string.length > 1
 
-  # make sure the seacrh string is not blank and consists of at least
-  # two letters
-  def sanitize_search_string
-    if @search_string.nil?
       redirect_back fallback_location: root_path,
-                    alert: I18n.t('controllers.no_search_term')
-      return
+                    alert: I18n.t('controllers.search_term_short')
     end
-    return if @search_string.length > 1
-    redirect_back fallback_location: root_path,
-                  alert: I18n.t('controllers.search_term_short')
-  end
 
-  def find_similar_tags
-    @similar_tags = Tag.similar_tags(@search_string)
-    @filtered_similar_tags = current_user.filter_tags(@similar_tags)
-  end
+    def find_similar_tags
+      @similar_tags = Tag.similar_tags(@search_string)
+      @filtered_similar_tags = current_user.filter_tags(@similar_tags)
+    end
 end
diff --git a/app/controllers/sections_controller.rb b/app/controllers/sections_controller.rb
index 00103d105..f7a87b997 100644
--- a/app/controllers/sections_controller.rb
+++ b/app/controllers/sections_controller.rb
@@ -56,46 +56,48 @@ def display
 
   private
 
-  def set_section
-    @section = Section.find_by_id(params[:id])
-    return if @section.present?
-    redirect_to :root, alert: I18n.t('controllers.no_section')
-  end
+    def set_section
+      @section = Section.find_by_id(params[:id])
+      return if @section.present?
 
-  def section_params
-    params.require(:section).permit(:title, :display_number, :chapter_id,
-                                    :details, :hidden,
-                                    tag_ids: [], lesson_ids: [])
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_section')
+    end
 
-  # inserts the section in the correct position if predecessor is given,
-  # otherwise just saves
-  def insert_or_save
-    position = params[:section][:predecessor]
-    if position.present?
-      @section.insert_at(position.to_i + 1)
-    else
-      @section.save
+    def section_params
+      params.require(:section).permit(:title, :display_number, :chapter_id,
+                                      :details, :hidden,
+                                      tag_ids: [], lesson_ids: [])
     end
-  end
 
-  # updates the position of the section if predecessor is given
-  def update_position
-    predecessor = params[:section][:predecessor]
-    return unless predecessor.present?
-    position = predecessor.to_i
-    if position > @section.position && @old_chapter == @section.chapter
-      position -= 1
+    # inserts the section in the correct position if predecessor is given,
+    # otherwise just saves
+    def insert_or_save
+      position = params[:section][:predecessor]
+      if position.present?
+        @section.insert_at(position.to_i + 1)
+      else
+        @section.save
+      end
     end
-    @section.insert_at(position + 1)
-  end
 
-  def update_tags_order
-    tags_order = params[:section][:tag_ids].map(&:to_i) - [0]
-    SectionTagJoin.acts_as_list_no_update do
-      @section.section_tag_joins.each do |st|
-        st.update(tag_position: tags_order.index(st.tag_id))
+    # updates the position of the section if predecessor is given
+    def update_position
+      predecessor = params[:section][:predecessor]
+      return unless predecessor.present?
+
+      position = predecessor.to_i
+      if position > @section.position && @old_chapter == @section.chapter
+        position -= 1
+      end
+      @section.insert_at(position + 1)
+    end
+
+    def update_tags_order
+      tags_order = params[:section][:tag_ids].map(&:to_i) - [0]
+      SectionTagJoin.acts_as_list_no_update do
+        @section.section_tag_joins.each do |st|
+          st.update(tag_position: tags_order.index(st.tag_id))
+        end
       end
     end
-  end
 end
diff --git a/app/controllers/sessions_controller.rb b/app/controllers/sessions_controller.rb
index ccb2e2f3c..ad3178f19 100644
--- a/app/controllers/sessions_controller.rb
+++ b/app/controllers/sessions_controller.rb
@@ -1,8 +1,7 @@
 class SessionsController < Devise::SessionsController
-
   # remove devise's flash message for succesful sign_in
   def create
     super
     flash.clear
   end
-end
\ No newline at end of file
+end
diff --git a/app/controllers/subjects_controller.rb b/app/controllers/subjects_controller.rb
index 1aec93c3f..6cd036d20 100644
--- a/app/controllers/subjects_controller.rb
+++ b/app/controllers/subjects_controller.rb
@@ -12,13 +12,13 @@ def new
     authorize! :new, @subject
   end
 
-	def edit
-	end
+  def edit
+  end
 
-	def  update
-		@subject.update(subject_params)
-		redirect_to classification_path
-	end
+  def update
+    @subject.update(subject_params)
+    redirect_to classification_path
+  end
 
   def create
     @subject = Subject.new(subject_params)
@@ -34,14 +34,14 @@ def destroy
 
   private
 
-  def set_subject
-    @subject = Subject.find_by_id(params[:id])
-    return if @subject.present?
+    def set_subject
+      @subject = Subject.find_by_id(params[:id])
+      return if @subject.present?
 
-    redirect_to root_path, alert: I18n.t('controllers.no_answer')
-  end
+      redirect_to root_path, alert: I18n.t('controllers.no_answer')
+    end
 
-  def subject_params
-  	params.require(:subject).permit(*Subject.globalize_attribute_names)
-  end
-end
\ No newline at end of file
+    def subject_params
+      params.require(:subject).permit(*Subject.globalize_attribute_names)
+    end
+end
diff --git a/app/controllers/submissions_controller.rb b/app/controllers/submissions_controller.rb
index 442b3ad1e..ad4422df9 100644
--- a/app/controllers/submissions_controller.rb
+++ b/app/controllers/submissions_controller.rb
@@ -23,13 +23,13 @@ def index
     @current_assignments = @lecture.current_assignments
     @previous_assignments = @lecture.previous_assignments
     @old_assignments = @assignments.expired.order('deadline DESC') -
-                         @previous_assignments
+                       @previous_assignments
     @future_assignments = @assignments.active.order(:deadline) -
-                            @current_assignments
+                          @current_assignments
   end
 
   def new
-  	@submission = Submission.new
+    @submission = Submission.new
     @submission.assignment = @assignment
     set_submission_locale
   end
@@ -38,7 +38,8 @@ def edit
   end
 
   def update
-  	return if @too_late
+    return if @too_late
+
     old_manuscript_data = @submission.manuscript_data
     @old_filename = @submission.manuscript_filename
     if submission_manuscript_params[:manuscript].present?
@@ -47,6 +48,7 @@ def update
                                                              .metadata,
                                                   :manuscript)
       return if @errors.present?
+
       @submission.save
       @errors = @submission.errors
       return unless @submission.valid?
@@ -67,11 +69,12 @@ def update
   end
 
   def create
-  	@submission = Submission.new(submission_create_params)
+    @submission = Submission.new(submission_create_params)
     @lecture = @submission&.assignment&.lecture
     set_submission_locale
     @too_late = @submission.not_updatable?
-  	return if @too_late
+    return if @too_late
+
     if submission_manuscript_params[:manuscript].present?
       @submission.manuscript = submission_manuscript_params[:manuscript]
       @errors = @submission.check_file_properties(@submission.manuscript
@@ -84,14 +87,17 @@ def create
     @assignment = @submission.assignment
     @errors = @submission.errors
     return unless @submission.valid?
+
     send_invitation_emails
     @submission.update(last_modification_by_users_at: Time.now)
     return unless @submission.manuscript
+
     send_upload_email(User.where(id: current_user.id))
   end
 
   def destroy
     return if @too_late
+
     @submission.destroy
   end
 
@@ -124,6 +130,7 @@ def join
 
   def leave
     return if @too_late
+
     if @submission.users.count == 1
       @error = I18n.t('submission.no_partners_no_leave')
       return
@@ -141,8 +148,8 @@ def cancel_new
   def show_manuscript
     if @submission && @submission.manuscript
       send_file @submission.manuscript.to_io,
-      					type: @submission.manuscript_mime_type,
-      					disposition: @disposition,
+                type: @submission.manuscript_mime_type,
+                disposition: @disposition,
                 filename: @submission.manuscript_filename
     elsif @submission
       redirect_to :start, alert: t('submission.no_manuscript_yet')
@@ -165,20 +172,20 @@ def show_correction
   end
 
   def refresh_token
-  	@submission.update(token: Submission.generate_token)
+    @submission.update(token: Submission.generate_token)
   end
 
   def enter_invitees
-  	@too_late = @submission.assignment.totally_expired?
+    @too_late = @submission.assignment.totally_expired?
   end
 
   def invite
-  	if @too_late
-  		render :create
-  		return
-  	end
-  	send_invitation_emails
-  	render :create
+    if @too_late
+      render :create
+      return
+    end
+    send_invitation_emails
+    render :create
   end
 
   def edit_correction
@@ -188,12 +195,13 @@ def cancel_edit_correction
   end
 
   def add_correction
-  	if correction_params[:correction].present?
+    if correction_params[:correction].present?
       @submission.correction = correction_params[:correction]
       @errors = @submission.check_file_properties_any(@submission.correction
                                                              .metadata,
-                                                  :correction)
+                                                      :correction)
       return if @errors.present?
+
       @submission.save
       @errors = @submission.errors
       return unless @submission.valid?
@@ -201,6 +209,7 @@ def add_correction
     @submission.update(correction_params)
     @errors = @submission.errors
     return if @errors.present?
+
     send_correction_upload_email(@submission.users)
   end
 
@@ -235,212 +244,220 @@ def reject
 
   private
 
-  def set_submission
-    @submission = Submission.find_by_id(params[:id])
-    @assignment = @submission&.assignment
-    @lecture = @assignment&.lecture
-    set_submission_locale
-    return if @submission
-    flash[:alert] = I18n.t('controllers.no_submission')
-    render js: "window.location='#{root_path}'"
-  end
+    def set_submission
+      @submission = Submission.find_by_id(params[:id])
+      @assignment = @submission&.assignment
+      @lecture = @assignment&.lecture
+      set_submission_locale
+      return if @submission
 
-  def submission_create_params
-    params.require(:submission).permit(:tutorial_id, :assignment_id)
-  end
+      flash[:alert] = I18n.t('controllers.no_submission')
+      render js: "window.location='#{root_path}'"
+    end
 
-  # disallow modification of assignment
-  def submission_update_params
-    params.require(:submission).permit(:tutorial_id)
-  end
+    def submission_create_params
+      params.require(:submission).permit(:tutorial_id, :assignment_id)
+    end
 
-  # disallow modification of assignment
-  def submission_manuscript_params
-    params.require(:submission).permit(:manuscript)
-  end
+    # disallow modification of assignment
+    def submission_update_params
+      params.require(:submission).permit(:tutorial_id)
+    end
 
-  def set_assignment
-    @assignment = Assignment.find_by_id(params[:assignment_id])
-    @lecture = @assignment&.lecture
-    set_submission_locale
-    return if @assignment
-    flash[:alert] = I18n.t('controllers.no_assignment')
-    render js: "window.location='#{root_path}'"
-    return
-  end
+    # disallow modification of assignment
+    def submission_manuscript_params
+      params.require(:submission).permit(:manuscript)
+    end
 
-  def set_lecture
-    @lecture = Lecture.find_by_id(params[:id])
-    set_submission_locale and return if @lecture
-    redirect_to :root, alert: I18n.t('controllers.no_lecture')
-  end
+    def set_assignment
+      @assignment = Assignment.find_by_id(params[:assignment_id])
+      @lecture = @assignment&.lecture
+      set_submission_locale
+      return if @assignment
 
-  def set_too_late
-    @too_late = @submission.not_updatable?
-  end
+      flash[:alert] = I18n.t('controllers.no_assignment')
+      render js: "window.location='#{root_path}'"
+      return
+    end
 
-  def set_submission_locale
-    I18n.locale = @lecture&.locale_with_inheritance || current_user.locale ||
+    def set_lecture
+      @lecture = Lecture.find_by_id(params[:id])
+      set_submission_locale and return if @lecture
+
+      redirect_to :root, alert: I18n.t('controllers.no_lecture')
+    end
+
+    def set_too_late
+      @too_late = @submission.not_updatable?
+    end
+
+    def set_submission_locale
+      I18n.locale = @lecture&.locale_with_inheritance || current_user.locale ||
                     I18n.default_locale
-  end
+    end
 
-  def join_params
-    params.require(:join).permit(:code, :assignment_id)
-  end
+    def join_params
+      params.require(:join).permit(:code, :assignment_id)
+    end
 
-  def invitation_params
-    params.require(:submission).permit(invitee_ids: [])
-  end
+    def invitation_params
+      params.require(:submission).permit(invitee_ids: [])
+    end
 
-  def correction_params
-    params.require(:submission).permit(:correction)
-  end
+    def correction_params
+      params.require(:submission).permit(:correction)
+    end
 
-  def move_params
-    params.require(:submission).permit(:tutorial_id)
-  end
+    def move_params
+      params.require(:submission).permit(:tutorial_id)
+    end
 
-  def send_invitation_emails
-    invitees = User.where(id: invitation_params[:invitee_ids])
-    invitees.each do |i|
-      NotificationMailer.with(recipient: i,
-                              locale: i.locale,
-                              assignment: @assignment,
-                              code: @submission.token,
-                              issuer: current_user)
-                        .submission_invitation_email.deliver_later
-    end
-    @submission.update(invited_user_ids: @submission.invited_user_ids |
-    																			 invitees.pluck(:id))
-  end
+    def send_invitation_emails
+      invitees = User.where(id: invitation_params[:invitee_ids])
+      invitees.each do |i|
+        NotificationMailer.with(recipient: i,
+                                locale: i.locale,
+                                assignment: @assignment,
+                                code: @submission.token,
+                                issuer: current_user)
+                          .submission_invitation_email.deliver_later
+      end
+      @submission.update(invited_user_ids: @submission.invited_user_ids |
+                                             invitees.pluck(:id))
+    end
 
-  def send_upload_email(users)
-    users.email_for_submission_upload.each do |u|
-      NotificationMailer.with(recipient: u,
-                              locale: u.locale,
-                              submission: @submission,
-                              uploader: current_user,
-                              filename: @submission.manuscript_filename)
-                        .submission_upload_email.deliver_later
+    def send_upload_email(users)
+      users.email_for_submission_upload.each do |u|
+        NotificationMailer.with(recipient: u,
+                                locale: u.locale,
+                                submission: @submission,
+                                uploader: current_user,
+                                filename: @submission.manuscript_filename)
+                          .submission_upload_email.deliver_later
+      end
     end
-  end
 
-  def send_upload_removal_email(users)
-    users.email_for_submission_removal.each do |u|
-      NotificationMailer.with(recipient: u,
-                              locale: u.locale,
-                              submission: @submission,
-                              remover: current_user,
-                              filename: @old_filename)
-                        .submission_upload_removal_email.deliver_later
+    def send_upload_removal_email(users)
+      users.email_for_submission_removal.each do |u|
+        NotificationMailer.with(recipient: u,
+                                locale: u.locale,
+                                submission: @submission,
+                                remover: current_user,
+                                filename: @old_filename)
+                          .submission_upload_removal_email.deliver_later
+      end
     end
-  end
 
-  def send_correction_upload_email(users)
-    users.email_for_correction_upload.each do |u|
-      NotificationMailer.with(recipient: u,
-                              locale: u.locale,
-                              submission: @submission,
-                              tutor: current_user)
-                        .correction_upload_email.deliver_later
+    def send_correction_upload_email(users)
+      users.email_for_correction_upload.each do |u|
+        NotificationMailer.with(recipient: u,
+                                locale: u.locale,
+                                submission: @submission,
+                                tutor: current_user)
+                          .correction_upload_email.deliver_later
+      end
     end
-  end
 
-  def send_acceptance_email(users)
-    users.email_for_submission_decision.each do |u|
-      NotificationMailer.with(recipient: u,
-                              locale: u.locale,
-                              submission: @submission)
-                        .submission_acceptance_email.deliver_later
+    def send_acceptance_email(users)
+      users.email_for_submission_decision.each do |u|
+        NotificationMailer.with(recipient: u,
+                                locale: u.locale,
+                                submission: @submission)
+                          .submission_acceptance_email.deliver_later
+      end
     end
-  end
 
-  def send_rejection_email(users)
-    users.email_for_submission_decision.each do |u|
-      NotificationMailer.with(recipient: u,
-                              locale: u.locale,
-                              submission: @submission)
-                        .submission_rejection_email.deliver_later
+    def send_rejection_email(users)
+      users.email_for_submission_decision.each do |u|
+        NotificationMailer.with(recipient: u,
+                                locale: u.locale,
+                                submission: @submission)
+                          .submission_rejection_email.deliver_later
+      end
     end
-  end
 
-  def check_code_validity
-    if !@submission && @assignment
-      @error = I18n.t('submission.invalid_code_for_assignment',
-                      assignment: @assignment.title)
-    elsif !@submission
-      @error = I18n.t('submission.invalid_code')
-    elsif @assignment&.totally_expired?
-      @error = I18n.t('submission.assignment_expired')
-    elsif @submission.correction
-      @error = I18n.t('submission.already_corrected')
-    elsif current_user.in?(@submission.users)
-      @error = I18n.t('submission.already_in')
-    elsif !@submission.tutorial.lecture.in?(current_user.lectures)
-      @error = I18n.t('submission.lecture_not_subscribed')
+    def check_code_validity
+      if !@submission && @assignment
+        @error = I18n.t('submission.invalid_code_for_assignment',
+                        assignment: @assignment.title)
+      elsif !@submission
+        @error = I18n.t('submission.invalid_code')
+      elsif @assignment&.totally_expired?
+        @error = I18n.t('submission.assignment_expired')
+      elsif @submission.correction
+        @error = I18n.t('submission.already_corrected')
+      elsif current_user.in?(@submission.users)
+        @error = I18n.t('submission.already_in')
+      elsif !@submission.tutorial.lecture.in?(current_user.lectures)
+        @error = I18n.t('submission.lecture_not_subscribed')
+      end
     end
-  end
 
-  def check_code_and_join
-  	check_code_validity
-  	unless @error
-    	@join = UserSubmissionJoin.new(user: current_user,
-    														 		 submission: @submission)
-    	@join.save
-    	if @join.valid?
-        @submission.update(last_modification_by_users_at: Time.now)
-        send_join_email
-        remove_invitee_status
-      else
-    		@error = @join.errors[:base].join(', ')
-    	end
+    def check_code_and_join
+      check_code_validity
+      unless @error
+        @join = UserSubmissionJoin.new(user: current_user,
+                                       submission: @submission)
+        @join.save
+        if @join.valid?
+          @submission.update(last_modification_by_users_at: Time.now)
+          send_join_email
+          remove_invitee_status
+        else
+          @error = @join.errors[:base].join(', ')
+        end
+      end
     end
-  end
 
-  def send_join_email
-    (@submission.users.email_for_submission_join - [current_user]).each do |u|
-      NotificationMailer.with(recipient: u,
-                              locale: u.locale,
-                              submission: @submission,
-                              user: current_user)
-                        .submission_join_email.deliver_later
+    def send_join_email
+      (@submission.users.email_for_submission_join - [current_user]).each do |u|
+        NotificationMailer.with(recipient: u,
+                                locale: u.locale,
+                                submission: @submission,
+                                user: current_user)
+                          .submission_join_email.deliver_later
+      end
     end
-  end
 
-  def send_leave_email
-    (@submission.users.email_for_submission_leave - [current_user]).each do |u|
-      NotificationMailer.with(recipient: u,
-                              locale: u.locale,
-                              submission: @submission,
-                              user: current_user)
-                        .submission_leave_email.deliver_later
+    def send_leave_email
+      (@submission.users.email_for_submission_leave - [current_user]).each do |u|
+        NotificationMailer.with(recipient: u,
+                                locale: u.locale,
+                                submission: @submission,
+                                user: current_user)
+                          .submission_leave_email.deliver_later
+      end
     end
-  end
 
-  def remove_invitee_status
-  	@submission.update(invited_user_ids: @submission.invited_user_ids -
-  																				 [current_user.id])
-  end
+    def remove_invitee_status
+      @submission.update(invited_user_ids: @submission.invited_user_ids -
+                                             [current_user.id])
+    end
 
-  def check_student_status
-    return if current_user.proper_student_in?(@lecture)
-    redirect_to :root, alert: I18n.t('controllers.no_student_status_in_lecture')
-  end
+    def check_student_status
+      return if current_user.proper_student_in?(@lecture)
 
-  def check_if_tutorials
-    return if @lecture.tutorials.any?
-    redirect_to :root, alert: I18n.t('controllers.no_tutorials_in_lecture')
-  end
+      redirect_to :root,
+                  alert: I18n.t('controllers.no_student_status_in_lecture')
+    end
 
-  def check_if_assignments
-    return if @lecture.assignments.any?
-    redirect_to :root, alert: I18n.t('controllers.no_assignments_in_lecture')
-  end
+    def check_if_tutorials
+      return if @lecture.tutorials.any?
 
-  def set_disposition
-    @disposition = params[:download] == 'true' ? 'attachment' : 'inline'
-    accepted = @submission.assignment.accepted_file_type
-    return unless accepted.in?(Assignment.non_inline_file_types)
-    @disposition = 'attachment'
-  end
-end
\ No newline at end of file
+      redirect_to :root, alert: I18n.t('controllers.no_tutorials_in_lecture')
+    end
+
+    def check_if_assignments
+      return if @lecture.assignments.any?
+
+      redirect_to :root, alert: I18n.t('controllers.no_assignments_in_lecture')
+    end
+
+    def set_disposition
+      @disposition = params[:download] == 'true' ? 'attachment' : 'inline'
+      accepted = @submission.assignment.accepted_file_type
+      return unless accepted.in?(Assignment.non_inline_file_types)
+
+      @disposition = 'attachment'
+    end
+end
diff --git a/app/controllers/tags_controller.rb b/app/controllers/tags_controller.rb
index a27e4eafa..574a42d84 100644
--- a/app/controllers/tags_controller.rb
+++ b/app/controllers/tags_controller.rb
@@ -11,7 +11,6 @@ class TagsController < ApplicationController
                               :render_tag_title]
   layout 'administration'
 
-
   def current_ability
     @current_ability ||= TagAbility.new(current_user)
   end
@@ -62,6 +61,7 @@ def new
   def update
     # first, check if errors from check_permission callback are present
     return if @errors.present?
+
     @tag.update(tag_params)
     if @tag.valid?
       @tag.update(realizations: realization_params)
@@ -144,10 +144,10 @@ def search
       fulltext search_params[:title]
     end
     course_ids = if search_params[:all_courses] == '1'
-                   []
-                 elsif search_params[:course_ids] != ['']
-                   search_params[:course_ids]
-                 end
+      []
+    elsif search_params[:course_ids] != ['']
+      search_params[:course_ids]
+    end
     search.build do
       with(:course_ids, course_ids)
       paginate page: params[:page], per_page: per_page
@@ -170,10 +170,13 @@ def postprocess
     @tags_hash.each do |t, section_data|
       tag = Tag.find_by_id(t)
       next unless tag
+
       section_data.each do |s, v|
         next if v.to_i == 0
+
         section = Section.find(s)
         next unless section
+
         if !tag.in?(section.tags)
           section.tags << tag
         end
@@ -195,175 +198,176 @@ def render_tag_title
 
   private
 
-  def set_tag
-    @tag = Tag.find_by_id(params[:id])
-    return if @tag.present?
-    redirect_to :root, alert: I18n.t('controllers.no_tag')
-  end
+    def set_tag
+      @tag = Tag.find_by_id(params[:id])
+      return if @tag.present?
 
-  # set up cytoscape graph data for neighbourhood subgraph of @tag,
-  # using only neighbourhood tags that are allowd by the user's
-  # profile settings, depending on the parameters (selection/depth) that were
-  # specified by the user)
-  def set_related_tags_for_user
-    @depth = 2
-    depth_param = params[:depth].to_i
-    @depth = depth_param if depth_param.in?([1, 2])
-    overrule_subscription_type = false
-    selection = params[:selection].to_i
-    if selection.in?([1, 2, 3])
-      overrule_subscription_type = selection
-    end
-    @selection_type = if overrule_subscription_type
-                         selection
-                       else
-                         current_user.subscription_type
-                       end
-    user_tags = current_user.visible_tags(overrule_subscription_type: overrule_subscription_type)
-    @related_tags = @tag.related_tags & user_tags
-    @tags_in_neighbourhood = if @depth == 2
-                               Tag.related_tags(@related_tags) & user_tags
-                             else
-                               []
-                             end
-    @tags = [@tag] + @related_tags + @tags_in_neighbourhood
-    @graph_elements = Tag.to_cytoscape(@tags, @tag,
-                                       highlight_related_tags: @depth == 2)
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_tag')
+    end
 
-  # set up cytoscape graph data for neighbourhood subgraph of @tag,
-  def set_related_tags
-    related_tags = @tag.related_tags
-    tags_in_neighbourhood = Tag.related_tags(related_tags)
-    @graph_elements = Tag.to_cytoscape([@tag] + related_tags +
-                                       tags_in_neighbourhood, @tag)
-  end
+    # set up cytoscape graph data for neighbourhood subgraph of @tag,
+    # using only neighbourhood tags that are allowd by the user's
+    # profile settings, depending on the parameters (selection/depth) that were
+    # specified by the user)
+    def set_related_tags_for_user
+      @depth = 2
+      depth_param = params[:depth].to_i
+      @depth = depth_param if depth_param.in?([1, 2])
+      overrule_subscription_type = false
+      selection = params[:selection].to_i
+      if selection.in?([1, 2, 3])
+        overrule_subscription_type = selection
+      end
+      @selection_type = if overrule_subscription_type
+        selection
+      else
+        current_user.subscription_type
+      end
+      user_tags = current_user.visible_tags(overrule_subscription_type: overrule_subscription_type)
+      @related_tags = @tag.related_tags & user_tags
+      @tags_in_neighbourhood = if @depth == 2
+        Tag.related_tags(@related_tags) & user_tags
+      else
+        []
+      end
+      @tags = [@tag] + @related_tags + @tags_in_neighbourhood
+      @graph_elements = Tag.to_cytoscape(@tags, @tag,
+                                         highlight_related_tags: @depth == 2)
+    end
 
-  def set_up_tag
-    @tag = Tag.new
-    set_notions
-    related_tag = Tag.find_by_id(params[:related_tag])
-    @tag.related_tags << related_tag if related_tag.present?
-  end
+    # set up cytoscape graph data for neighbourhood subgraph of @tag,
+    def set_related_tags
+      related_tags = @tag.related_tags
+      tags_in_neighbourhood = Tag.related_tags(related_tags)
+      @graph_elements = Tag.to_cytoscape([@tag] + related_tags +
+                                         tags_in_neighbourhood, @tag)
+    end
 
-  def add_course
-    course = Course.find_by_id(params[:course])
-    @tag.courses << course if course.present?
-  end
+    def set_up_tag
+      @tag = Tag.new
+      set_notions
+      related_tag = Tag.find_by_id(params[:related_tag])
+      @tag.related_tags << related_tag if related_tag.present?
+    end
 
-  def add_section
-    section = Section.find_by_id(params[:section])
-    if section
-      @tag.sections << section
-      I18n.locale = section.lecture.locale || current_user.locale
+    def add_course
+      course = Course.find_by_id(params[:course])
+      @tag.courses << course if course.present?
     end
-  end
 
-  def add_medium
-    medium = Medium.find_by_id(params[:medium])
-    if medium
+    def add_section
+      section = Section.find_by_id(params[:section])
+      if section
+        @tag.sections << section
+        I18n.locale = section.lecture.locale || current_user.locale
+      end
+    end
+
+    def add_medium
+      medium = Medium.find_by_id(params[:medium])
+      if medium
         I18n.locale = medium.locale_with_inheritance || current_user.locale
         @tag.media << medium
+      end
     end
-  end
 
-  def add_lesson
-    lesson = Lesson.find_by_id(params[:lesson])
-    if lesson
-      @tag.lessons << lesson
-      I18n.locale = lesson.lecture.locale || current_user.locale
+    def add_lesson
+      lesson = Lesson.find_by_id(params[:lesson])
+      if lesson
+        @tag.lessons << lesson
+        I18n.locale = lesson.lecture.locale || current_user.locale
+      end
     end
-  end
 
-  def add_talk
-    talk = Talk.find_by_id(params[:talk])
-    if talk
-      @tag.talks << talk
-      I18n.locale = talk.lecture.locale || current_user.locale
+    def add_talk
+      talk = Talk.find_by_id(params[:talk])
+      if talk
+        @tag.talks << talk
+        I18n.locale = talk.lecture.locale || current_user.locale
+      end
     end
-  end
 
-  def check_for_consent
-    redirect_to consent_profile_path unless current_user.consents
-  end
+    def check_for_consent
+      redirect_to consent_profile_path unless current_user.consents
+    end
 
-  def tag_params
-    params.require(:tag).permit(related_tag_ids: [],
-                                notions_attributes: [:title, :locale, :id,
-                                  :_destroy],
-                                aliases_attributes: [:title, :locale, :id,
-                                  :_destroy],
-                                course_ids: [],
-                                section_ids: [],
-                                lesson_ids: [],
-                                talk_ids: [],
-                                media_ids: [])
-  end
+    def tag_params
+      params.require(:tag).permit(related_tag_ids: [],
+                                  notions_attributes: [:title, :locale, :id,
+                                                       :_destroy],
+                                  aliases_attributes: [:title, :locale, :id,
+                                                       :_destroy],
+                                  course_ids: [],
+                                  section_ids: [],
+                                  lesson_ids: [],
+                                  talk_ids: [],
+                                  media_ids: [])
+    end
 
-  def realization_params
-    (params.require(:tag).permit(realizations: [])[:realizations] - [''])
-      .map { |r| r.split('-') }
-      .map { |x| [x.first, x.second.to_i] }
-  end
+    def realization_params
+      (params.require(:tag).permit(realizations: [])[:realizations] - [''])
+        .map { |r| r.split('-') }
+        .map { |x| [x.first, x.second.to_i] }
+    end
 
-  def check_permissions
-    @errors = {}
-    return if current_user.admin?
-    # of current user is not an admin, he can add/remove courses only
-    # as course editor with inheritance/course_editor
-    permission_errors
-  end
+    def check_permissions
+      @errors = {}
+      return if current_user.admin?
 
-  def permission_errors
-    errors = []
-    unless removed_courses.all? { |c| c.removable_by?(current_user) }
-      errors.push(error_hash['remove_course'])
-    end
-    unless added_courses.all? { |c| c.addable_by?(current_user) }
-      errors.push(error_hash['add_course'])
+      # of current user is not an admin, he can add/remove courses only
+      # as course editor with inheritance/course_editor
+      permission_errors
     end
-    @errors[:courses] = errors if errors.present?
-  end
 
-  def check_creation_permission
-    @modal = (params[:tag][:modal] == 'true')
-    @tag = Tag.new
-    check_permissions
-  end
+    def permission_errors
+      errors = []
+      unless removed_courses.all? { |c| c.removable_by?(current_user) }
+        errors.push(error_hash['remove_course'])
+      end
+      unless added_courses.all? { |c| c.addable_by?(current_user) }
+        errors.push(error_hash['add_course'])
+      end
+      @errors[:courses] = errors if errors.present?
+    end
 
-  def removed_courses
-    @tag.courses - Course.where(id: tag_params[:course_ids])
-  end
+    def check_creation_permission
+      @modal = (params[:tag][:modal] == 'true')
+      @tag = Tag.new
+      check_permissions
+    end
 
-  def added_courses
-    Course.where(id: tag_params[:course_ids]) - @tag.courses
-  end
+    def removed_courses
+      @tag.courses - Course.where(id: tag_params[:course_ids])
+    end
 
-  def set_notions
-    @tag.notions.new(locale: I18n.locale)
-    (I18n.available_locales - [I18n.locale]).each do |l|
-      @tag.notions.new(locale: l)
+    def added_courses
+      Course.where(id: tag_params[:course_ids]) - @tag.courses
     end
-  end
 
-  def locale
-    locale = if params[:from] == 'course'
-               @tag.courses&.first&.locale
-             elsif params[:from] == 'medium'
-               @tag.media&.first&.locale_with_inheritance
-             elsif params[:from] == 'section'
-               @tag.sections&.first&.lecture&.locale_with_inheritance
-             end
-    locale || current_user.locale
-  end
+    def set_notions
+      @tag.notions.new(locale: I18n.locale)
+      (I18n.available_locales - [I18n.locale]).each do |l|
+        @tag.notions.new(locale: l)
+      end
+    end
 
-  def error_hash
-    { 'remove_course' => I18n.t('controllers.no_removal_rights'),
-      'add_course' => I18n.t('controllers.no_adding_rights') }
-  end
+    def locale
+      locale = if params[:from] == 'course'
+        @tag.courses&.first&.locale
+      elsif params[:from] == 'medium'
+        @tag.media&.first&.locale_with_inheritance
+      elsif params[:from] == 'section'
+        @tag.sections&.first&.lecture&.locale_with_inheritance
+      end
+      locale || current_user.locale
+    end
 
-  def search_params
-    params.require(:search).permit(:title, :all_courses, :per, course_ids: [])
-  end
+    def error_hash
+      { 'remove_course' => I18n.t('controllers.no_removal_rights'),
+        'add_course' => I18n.t('controllers.no_adding_rights') }
+    end
 
+    def search_params
+      params.require(:search).permit(:title, :all_courses, :per, course_ids: [])
+    end
 end
diff --git a/app/controllers/terms_controller.rb b/app/controllers/terms_controller.rb
index 6717853d3..af473afe0 100644
--- a/app/controllers/terms_controller.rb
+++ b/app/controllers/terms_controller.rb
@@ -66,18 +66,19 @@ def set_active
 
   private
 
-  def set_term
-    @id = params[:id]
-    @term = Term.find_by_id(@id)
-    return if @term
-    redirect_to terms_path, alert: I18n.t('controllers.no_term')
-  end
+    def set_term
+      @id = params[:id]
+      @term = Term.find_by_id(@id)
+      return if @term
 
-  def term_params
-    params.require(:term).permit(:year, :season)
-  end
+      redirect_to terms_path, alert: I18n.t('controllers.no_term')
+    end
 
-  def active_term_params
-    params.permit(:active_term)
-  end
+    def term_params
+      params.require(:term).permit(:year, :season)
+    end
+
+    def active_term_params
+      params.permit(:active_term)
+    end
 end
diff --git a/app/controllers/tutorials_controller.rb b/app/controllers/tutorials_controller.rb
index 9bbcfc12a..f849a708a 100644
--- a/app/controllers/tutorials_controller.rb
+++ b/app/controllers/tutorials_controller.rb
@@ -26,7 +26,7 @@ def index
     authorize! :index, Tutorial.new, @lecture
     @assignments = @lecture.assignments.order('deadline DESC')
     @assignment = Assignment.find_by_id(params[:assignment]) ||
-                    @assignments&.first
+                  @assignments&.first
     if current_user.editor_or_teacher_in?(@lecture)
       @tutorials = @lecture.tutorials
     else
@@ -41,7 +41,7 @@ def overview
     authorize! :overview, Tutorial.new, @lecture
     @assignments = @lecture.assignments.order('deadline DESC')
     @assignment = Assignment.find_by_id(params[:assignment]) ||
-                    @assignments&.first
+                  @assignments&.first
     @tutorials = @lecture.tutorials
   end
 
@@ -117,81 +117,88 @@ def validate_certificate
   def export_teams
     respond_to do |format|
       format.html { head :ok }
-      format.csv { send_data @tutorial.teams_to_csv(@assignment),
-                             filename: "#{@tutorial.title}-#{@assignment.title}.csv" }
+      format.csv {
+        send_data @tutorial.teams_to_csv(@assignment),
+                  filename: "#{@tutorial.title}-#{@assignment.title}.csv"
+      }
     end
   end
 
   private
 
-  def set_tutorial
-    @tutorial = Tutorial.find_by_id(params[:id])
-    @lecture = @tutorial&.lecture
-    set_tutorial_locale and return if @tutorial
-    redirect_to :root, alert: I18n.t('controllers.no_tutorial')
-  end
+    def set_tutorial
+      @tutorial = Tutorial.find_by_id(params[:id])
+      @lecture = @tutorial&.lecture
+      set_tutorial_locale and return if @tutorial
 
-  def set_assignment
-    @assignment = Assignment.find_by_id(params[:ass_id])
-    return if @assignment
-    redirect_to :root, alert: I18n.t('controllers.no_assignment')
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_tutorial')
+    end
 
-  def set_lecture
-    @lecture = Lecture.find_by_id(params[:id])
-    set_tutorial_locale and return if @lecture
-    redirect_to :root, alert: I18n.t('controllers.no_lecture')
-  end
+    def set_assignment
+      @assignment = Assignment.find_by_id(params[:ass_id])
+      return if @assignment
 
-  def set_lecture_from_form
-    @lecture = Lecture.find_by_id(tutorial_params[:lecture_id])
-    return if @lecture
-    redirect_to :root, alert: I18n.t('controllers.no_lecture')
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_assignment')
+    end
+
+    def set_lecture
+      @lecture = Lecture.find_by_id(params[:id])
+      set_tutorial_locale and return if @lecture
 
-  def set_tutorial_locale
-    I18n.locale = @lecture&.locale_with_inheritance || current_user.locale ||
+      redirect_to :root, alert: I18n.t('controllers.no_lecture')
+    end
+
+    def set_lecture_from_form
+      @lecture = Lecture.find_by_id(tutorial_params[:lecture_id])
+      return if @lecture
+
+      redirect_to :root, alert: I18n.t('controllers.no_lecture')
+    end
+
+    def set_tutorial_locale
+      I18n.locale = @lecture&.locale_with_inheritance || current_user.locale ||
                     I18n.default_locale
-  end
+    end
 
-  def can_view_index
-    return if current_user.in?(@lecture.tutors) || current_user.editor_or_teacher_in?(@lecture)
-    redirect_to :root, alert: I18n.t('controllers.no_tutor_in_this_lecture')
-  end
+    def can_view_index
+      return if current_user.in?(@lecture.tutors) || current_user.editor_or_teacher_in?(@lecture)
 
-  def tutorial_params
-    params.require(:tutorial).permit(:title, :lecture_id, tutor_ids: [])
-  end
+      redirect_to :root, alert: I18n.t('controllers.no_tutor_in_this_lecture')
+    end
 
-  def bulk_params
-    params.permit(:package)
-  end
+    def tutorial_params
+      params.require(:tutorial).permit(:title, :lecture_id, tutor_ids: [])
+    end
 
-  def bulk_download(zipped, end_of_file='')
-    if zipped.is_a?(StringIO)
-    send_data zipped.read,
-              filename: @assignment.title + '@' + @tutorial.title + end_of_file + '.zip',
-              type: 'application/zip',
-              disposition: 'attachment'
-    else
-      flash[:alert] = I18n.t('controllers.tutorials.bulk_download_failed',
-                             message: zipped)
-      redirect_to lecture_tutorials_path(@tutorial.lecture,
-                                         params:
-                                          { assignment: @assignment.id,
-                                            tutorial: @tutorial.id })
+    def bulk_params
+      params.permit(:package)
     end
-  end
 
-  def send_correction_upload_emails
-    @report[:successful_saves]&.each do |submission|
-      submission.users.email_for_correction_upload.each do |u|
-        NotificationMailer.with(recipient: u,
-                                locale: u.locale,
-                                submission: submission,
-                                tutor: current_user)
-                          .correction_upload_email.deliver_later
+    def bulk_download(zipped, end_of_file = '')
+      if zipped.is_a?(StringIO)
+        send_data zipped.read,
+                  filename: @assignment.title + '@' + @tutorial.title + end_of_file + '.zip',
+                  type: 'application/zip',
+                  disposition: 'attachment'
+      else
+        flash[:alert] = I18n.t('controllers.tutorials.bulk_download_failed',
+                               message: zipped)
+        redirect_to lecture_tutorials_path(@tutorial.lecture,
+                                           params:
+                                            { assignment: @assignment.id,
+                                              tutorial: @tutorial.id })
       end
     end
-  end
-end
\ No newline at end of file
+
+    def send_correction_upload_emails
+      @report[:successful_saves]&.each do |submission|
+        submission.users.email_for_correction_upload.each do |u|
+          NotificationMailer.with(recipient: u,
+                                  locale: u.locale,
+                                  submission: submission,
+                                  tutor: current_user)
+                            .correction_upload_email.deliver_later
+        end
+      end
+    end
+end
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 405e20bf7..0ed0ae4c2 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -39,6 +39,7 @@ def elevate
     @user = User.find(elevate_params[:id])
     admin = elevate_params[:admin] == '1'
     return unless admin
+
     # enforce a name
     if @user.name.blank?
       name = @user.email.split('@')[0]
@@ -90,23 +91,25 @@ def delete_account
 
   private
 
-  def elevate_params
-    params.require(:generic_user).permit(:id, :admin, :editor, :teacher, :name)
-  end
+    def elevate_params
+      params.require(:generic_user).permit(:id, :admin, :editor, :teacher,
+                                           :name)
+    end
 
-  def user_params
-    params.require(:user).permit(:name, :email, :homepage,
-                                 :current_lecture_id,:image)
-  end
+    def user_params
+      params.require(:user).permit(:name, :email, :homepage,
+                                   :current_lecture_id, :image)
+    end
 
-  def set_user
-    @user = User.find_by_id(params[:id])
-    return unless @user.nil?
-    redirect_to :root, alert: I18n.t('controllers.no_medium')
-  end
+    def set_user
+      @user = User.find_by_id(params[:id])
+      return unless @user.nil?
 
-  def set_elevated_users
-    @elevated_users = User.where(admin: true).or(User.proper_editors)
-                          .or(User.teachers)
-  end
-end
\ No newline at end of file
+      redirect_to :root, alert: I18n.t('controllers.no_medium')
+    end
+
+    def set_elevated_users
+      @elevated_users = User.where(admin: true).or(User.proper_editors)
+                            .or(User.teachers)
+    end
+end
diff --git a/app/controllers/vertices_controller.rb b/app/controllers/vertices_controller.rb
index 776389313..3f3e027d9 100644
--- a/app/controllers/vertices_controller.rb
+++ b/app/controllers/vertices_controller.rb
@@ -50,51 +50,54 @@ def destroy
 
   private
 
-  def set_values
-    @quiz_id = params[:quiz_id]
-    @quiz = Quiz.find_by_id(@quiz_id)
-    @params_v = params[:vertex]
-  end
+    def set_values
+      @quiz_id = params[:quiz_id]
+      @quiz = Quiz.find_by_id(@quiz_id)
+      @params_v = params[:vertex]
+    end
 
-  def set_update_vertex_params
-    @vertex_id = @params_v[:vertex_id].to_i
-    @branching = {}
-    set_branching_hash
-    set_hide_array
-  end
+    def set_update_vertex_params
+      @vertex_id = @params_v[:vertex_id].to_i
+      @branching = {}
+      set_branching_hash
+      set_hide_array
+    end
 
-  def set_create_vertex_params
-    @sort = @params_v[:sort]
-    if @sort == 'import'
-      @quizzables = Medium.where(id: @params_v[:quizzable_ids],
-                                 type: ['Question', 'Remark'])
-      @success = @quizzables.any?
-    else
-      quizzable = @sort.constantize.create_prefilled(@params_v[:label],
-                                                      @quiz.teachable,
-                                                      @quiz.editors)
-      @success = quizzable.valid?
-      @quizzables = [quizzable]
+    def set_create_vertex_params
+      @sort = @params_v[:sort]
+      if @sort == 'import'
+        @quizzables = Medium.where(id: @params_v[:quizzable_ids],
+                                   type: ['Question', 'Remark'])
+        @success = @quizzables.any?
+      else
+        quizzable = @sort.constantize.create_prefilled(@params_v[:label],
+                                                       @quiz.teachable,
+                                                       @quiz.editors)
+        @success = quizzable.valid?
+        @quizzables = [quizzable]
+      end
     end
-  end
 
-  def set_branching_hash
-    @branching = {}
-    @params_v.keys.select { |k| k.start_with?('branching-') }.each do |k|
-      next if @params_v[k].to_i == 0
-      @branching[k.remove('branching-').to_h] = [@vertex_id, @params_v[k].to_i]
+    def set_branching_hash
+      @branching = {}
+      @params_v.keys.select { |k| k.start_with?('branching-') }.each do |k|
+        next if @params_v[k].to_i == 0
+
+        @branching[k.remove('branching-').to_h] =
+          [@vertex_id, @params_v[k].to_i]
+      end
     end
-  end
 
-  def set_hide_array
-    @hide = @params_v.keys.select { |k| k.start_with?('hide-') }
-                     .select { |h| @params_v[h] == '1' }
-                     .map { |h| h.remove('hide-').to_h }
-  end
+    def set_hide_array
+      @hide = @params_v.keys.select { |k| k.start_with?('hide-') }
+                       .select { |h| @params_v[h] == '1' }
+                       .map { |h| h.remove('hide-').to_h }
+    end
 
-  def check_permission
-    return if current_user.admin
-    return if current_user.can_edit?(@quiz)
-    redirect_to :root, alert: I18n.t('controllers.unauthorized')
-  end
+    def check_permission
+      return if current_user.admin
+      return if current_user.can_edit?(@quiz)
+
+      redirect_to :root, alert: I18n.t('controllers.unauthorized')
+    end
 end
diff --git a/app/controllers/watchlist_entries_controller.rb b/app/controllers/watchlist_entries_controller.rb
index f41c37de8..106e8644e 100644
--- a/app/controllers/watchlist_entries_controller.rb
+++ b/app/controllers/watchlist_entries_controller.rb
@@ -1,6 +1,5 @@
 # WatchlistEntriesController
 class WatchlistEntriesController < ApplicationController
-
   def current_ability
     @current_ability ||= WatchlistEntryAbility.new(current_user)
   end
diff --git a/app/controllers/watchlists_controller.rb b/app/controllers/watchlists_controller.rb
index 77bff44a2..fc616dbf9 100644
--- a/app/controllers/watchlists_controller.rb
+++ b/app/controllers/watchlists_controller.rb
@@ -71,6 +71,7 @@ def show
     authorize! :show, @watchlist
     @watchlists = current_user.watchlists
     return if @watchlist.watchlist_entries.empty?
+
     @watchlist_entries = paginated_results
     @media = @watchlist_entries.pluck(:medium_id)
   end
@@ -81,7 +82,6 @@ def add_medium
     @medium = Medium.find_by_id(params[:medium_id])
   end
 
-
   def update_order
     entries = params[:order].map { |id| WatchlistEntry.find_by_id(id) }
     authorize! :update_order, @watchlist, entries
@@ -104,9 +104,11 @@ def change_visibility
   end
 
   private
+
     def set_watchlist
       @watchlist = Watchlist.find_by_id(params[:id])
       return if @watchlist.present?
+
       redirect_to :root, alert: I18n.t('controllers.no_watchlist')
     end
 
@@ -130,6 +132,7 @@ def paginated_results
     def filter_results
       filter_results = @watchlist.watchlist_entries
       return filter_results unless params[:reverse]
+
       filter_results.reverse
     end
 
@@ -140,5 +143,4 @@ def update_params
     def create_params
       params.require(:watchlist).permit(:name, :description, :medium_id)
     end
-
-end
\ No newline at end of file
+end
diff --git a/app/helpers/announcements_helper.rb b/app/helpers/announcements_helper.rb
index 28203725c..9994c564b 100644
--- a/app/helpers/announcements_helper.rb
+++ b/app/helpers/announcements_helper.rb
@@ -6,6 +6,7 @@ def announcement_notification_item_header(announcement)
     unless announcement.lecture.present?
       return t('notifications.mampf_announcement')
     end
+
     t('notifications.lecture_announcement',
       title: announcement.lecture.title_for_viewers)
   end
@@ -14,6 +15,7 @@ def announcement_notification_item_header(announcement)
   def news_card_color(announcement)
     return '' unless user_signed_in?
     return 'bg-post-it-blue' if announcement.active?(current_user)
+
     ''
   end
 
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index c88cfef2e..23fb3040c 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -1,10 +1,10 @@
 # ApplicationHelper module
 module ApplicationHelper
-
-  #returns the path that is associated to the MaMpf brand in the navbar
+  # returns the path that is associated to the MaMpf brand in the navbar
   def home_path
     return start_path if user_signed_in?
-    root_path(params: { locale: I18n.locale})
+
+    root_path(params: { locale: I18n.locale })
   end
 
   # get current lecture from session object
@@ -30,6 +30,7 @@ def download_host
   def full_title(page_title = '')
     return page_title if action_name == 'play' && controller_name == 'media'
     return 'Quiz' if action_name == 'take' && controller_name == 'quizzes'
+
     base_title = 'MaMpf'
     if user_signed_in? && current_user.notifications.any?
       base_title += " (#{current_user.notifications.size})"
@@ -109,7 +110,7 @@ def media_names
   # Selects all media associated to lectures and lessons from a given list
   # of media
   def lecture_media(media)
-    media.where(teachable_type: ['Lecture', 'Lesson'] )
+    media.where(teachable_type: ['Lecture', 'Lesson'])
   end
 
   # Selects all media associated to courses from a given list of media
@@ -121,10 +122,10 @@ def course_media(media)
   # the given media are associated to.
   def lecture_course_teachables(media)
     teachables = media.pluck(:teachable_type, :teachable_id).uniq
-    course_ids = teachables.select { |t| t.first == 'Course'}.map(&:second)
-    lecture_ids = teachables.select { |t| t.first == 'Lecture'}.map(&:second)
-    lesson_ids = teachables.select { |t| t.first == 'Lesson'}.map(&:second)
-    talk_ids = teachables.select { |t| t.first == 'Talk'}.map(&:second)
+    course_ids = teachables.select { |t| t.first == 'Course' }.map(&:second)
+    lecture_ids = teachables.select { |t| t.first == 'Lecture' }.map(&:second)
+    lesson_ids = teachables.select { |t| t.first == 'Lesson' }.map(&:second)
+    talk_ids = teachables.select { |t| t.first == 'Talk' }.map(&:second)
     lecture_ids += Lesson.where(id: lesson_ids).pluck(:lecture_id).uniq
     lecture_ids += Talk.where(id: talk_ids).pluck(:lecture_id).uniq
     Course.where(id: course_ids) + Lecture.where(id: lecture_ids.uniq)
@@ -139,8 +140,8 @@ def relevant_media(teachable, media, limit)
     result = []
     if teachable.class == Course
       return media.where(teachable: teachable).order(:created_at)
-                                              .reverse_order
-                                              .first(limit)
+                  .reverse_order
+                  .first(limit)
     end
     media_ids = (teachable.media_with_inheritance.pluck(:id) & media.pluck(:id))
     Medium.where(id: media_ids).order(:created_at).reverse_order.first(limit)
@@ -152,6 +153,7 @@ def split_list(list, pieces = 4)
     groups = list.in_groups_of(group_size)
     diff = groups.count - pieces
     return groups if diff <= 0
+
     tail = groups.pop(diff).first(diff).flatten
     groups.last.concat(tail)
     groups
@@ -160,6 +162,7 @@ def split_list(list, pieces = 4)
   # returns true for 'media#enrich' action
   def enrich?(controller, action)
     return true if controller == 'media' && action == 'enrich'
+
     false
   end
 
@@ -168,6 +171,7 @@ def enrich?(controller, action)
   def shorten(title, max_letters)
     return '' unless title.present?
     return title unless title.length > max_letters
+
     title[0, max_letters - 3] + '...'
   end
 
@@ -176,7 +180,8 @@ def shorten(title, max_letters)
   def grouped_teachable_list
     list = []
     Course.all.each do |c|
-      lectures = [[c.short_title + ' (' + t('basics.all') + ')', 'Course-' + c.id.to_s]]
+      lectures = [[c.short_title + ' (' + t('basics.all') + ')',
+                   'Course-' + c.id.to_s]]
       c.lectures.includes(:term).each do |l|
         lectures.push [l.short_title_release, 'Lecture-' + l.id.to_s]
       end
@@ -206,6 +211,7 @@ def grouped_teachable_list_alternative
   # can edit all lectures associated to the course.
   def edit_or_show_lecture_path(lecture)
     return edit_lecture_path(lecture) if current_user.can_edit?(lecture)
+
     lecture_path(lecture)
   end
 
@@ -217,6 +223,7 @@ def edit_or_inspect_medium_path(medium)
        medium.editors_with_inheritance.include?(current_user)
       return edit_medium_path(medium)
     end
+
     inspect_medium_path(medium)
   end
 
@@ -224,10 +231,11 @@ def edit_or_inspect_medium_path(medium)
   # anything older than today or yesterday gets reduced to the day.month.year
   # yesterday's/today's dates are return as 'gestern/heute' plus hour:mins
   def human_readable_date(date)
-    return t('today')+ ', ' + date.strftime('%H:%M') if date.to_date == Date.today
+    return t('today') + ', ' + date.strftime('%H:%M') if date.to_date == Date.today
     if date.to_date == Date.yesterday
       return t('yesterday') + ', ' + date.strftime('%H:%M')
     end
+
     I18n.localize date, format: :concise
   end
 
@@ -266,12 +274,12 @@ def hide_as_class(value)
 
   def helpdesk(text, html)
     tag.i class: 'far fa-question-circle helpdesk ml-2',
-                  tabindex: -1,
-                  data: { toggle: 'popover',
-                          trigger: 'focus',
-                          content: text,
-                          html: html },
-                  title: t('info')
+          tabindex: -1,
+          data: { toggle: 'popover',
+                  trigger: 'focus',
+                  content: text,
+                  html: html },
+          title: t('info')
   end
 
   def realization_path(realization)
@@ -291,7 +299,7 @@ def get_announcements
   # Navbar items styling based on which page we are on
   # https://gist.github.com/mynameispj/5692162
   $active_css_class = "active-item"
-  
+
   def get_class_for_project(project)
     return request.params['project'] == project ? $active_css_class : ''
   end
@@ -310,9 +318,9 @@ def get_class_for_any_path(paths)
 
   def get_class_for_any_path_startswith(paths)
     if paths.any? { |path| request.path.starts_with?(path) }
-      return  $active_css_class
+      return $active_css_class
     end
+
     return ''
   end
-
 end
diff --git a/app/helpers/assignments_helper.rb b/app/helpers/assignments_helper.rb
index d61d3c0aa..ce0369e2f 100644
--- a/app/helpers/assignments_helper.rb
+++ b/app/helpers/assignments_helper.rb
@@ -2,11 +2,13 @@
 module AssignmentsHelper
   def cancel_editing_assignment_path(assignment)
     return cancel_edit_assignment_path(assignment) if assignment.persisted?
+
     cancel_new_assignment_path(params: { lecture: assignment.lecture })
   end
 
   def has_documents?(assignment)
     return false unless assignment.medium
+
     assignment.medium.video || assignment.medium.manuscript ||
       assignment.medium.geogebra ||
       assignment.medium.external_reference_link.present? ||
@@ -15,6 +17,7 @@ def has_documents?(assignment)
 
   def file_button_text(assignment)
     return I18n.t('basics.file') unless assignment.accepted_file_type == '.pdf'
+
     I18n.t('basics.files')
   end
 end
diff --git a/app/helpers/chapters_helper.rb b/app/helpers/chapters_helper.rb
index ac711d717..8d806f67b 100644
--- a/app/helpers/chapters_helper.rb
+++ b/app/helpers/chapters_helper.rb
@@ -4,4 +4,4 @@ def chapter_positions_for_select(chapter)
     [[t('basics.at_the_beginning'), 0]] + chapter.lecture.select_chapters -
       [[chapter.to_label, chapter.position]]
   end
-end
\ No newline at end of file
+end
diff --git a/app/helpers/clickers_helper.rb b/app/helpers/clickers_helper.rb
index 58f2f2c72..cde787a1e 100644
--- a/app/helpers/clickers_helper.rb
+++ b/app/helpers/clickers_helper.rb
@@ -10,4 +10,4 @@ def generate_qr(text)
     base64_output = Base64.encode64(qrcode.to_png({ xdim: 8 }))
     "data:image/png;base64,#{base64_output}"
   end
-end
\ No newline at end of file
+end
diff --git a/app/helpers/courses_helper.rb b/app/helpers/courses_helper.rb
index 34d9a028c..7b1758916 100644
--- a/app/helpers/courses_helper.rb
+++ b/app/helpers/courses_helper.rb
@@ -27,6 +27,7 @@ def course_link_or_text(course, user)
     unless user.admin || user.in?(course.editors)
       return course.title
     end
+
     link_to(course.title, edit_course_path(course))
   end
 
@@ -40,5 +41,4 @@ def course_edit_icon(course)
       tag.i class: 'far fa-edit'
     end
   end
-
 end
diff --git a/app/helpers/items_helper.rb b/app/helpers/items_helper.rb
index 2bb92a957..217a5c6cc 100644
--- a/app/helpers/items_helper.rb
+++ b/app/helpers/items_helper.rb
@@ -17,6 +17,7 @@ def select_script_items(lecture)
 
   def check_unless_hidden(item_id)
     return 'checked' unless Item.find_by_id(item_id)&.hidden
+
     ''
   end
 
diff --git a/app/helpers/lectures_helper.rb b/app/helpers/lectures_helper.rb
index 3123e56c8..c64225e9a 100644
--- a/app/helpers/lectures_helper.rb
+++ b/app/helpers/lectures_helper.rb
@@ -41,24 +41,28 @@ def days_short
   # unpublished lecture get a different link color
   def lectures_color(lecture)
     return '' if lecture.published?
+
     'unpublished'
   end
 
   # hidden chapters get a different color
   def chapter_card_color(chapter)
     return 'bg-mdb-color-lighten-5' unless chapter.hidden
+
     'greyed_out bg-grey'
   end
 
   # hidden chapters get a different header color
   def chapter_header_color(chapter)
     return 'bg-mdb-color-lighten-2' unless chapter.hidden
+
     ''
   end
 
   # hidden sections get a different color
   def section_color(section)
     return '' unless section.hidden
+
     'greyed_out'
   end
 
@@ -67,36 +71,42 @@ def section_background_color(section)
     unless !section.chapter.hidden && section.hidden
       return 'bg-mdb-color-lighten-6'
     end
+
     'bg-grey'
   end
 
   def news_color(news_count)
     return '' unless news_count.positive?
+
     'text-primary'
   end
 
   def lecture_header_color(subscribed, lecture)
     return '' unless subscribed
+
     result = 'text-light '
     result += if lecture.term
-                'bg-mdb-color-lighten-1'
-              else
-                'bg-info'
-              end
+      'bg-mdb-color-lighten-1'
+    else
+      'bg-info'
+    end
   end
 
   def circle_icon(subscribed)
     return 'fas fa-check-circle' if subscribed
+
     'far fa-circle'
   end
 
   def lecture_border(lecture)
     return '' if lecture.published?
+
     'border-danger'
   end
 
   def lecture_access_icon(lecture)
     return lecture_edit_icon if current_user.can_edit?(lecture)
+
     lecture_view_icon
   end
 
diff --git a/app/helpers/lessons_helper.rb b/app/helpers/lessons_helper.rb
index 0f2e016d8..0653e9207 100644
--- a/app/helpers/lessons_helper.rb
+++ b/app/helpers/lessons_helper.rb
@@ -10,6 +10,7 @@ def lesson_tag_selection(lesson)
 
   def edit_or_show_lesson_path(lesson)
     return edit_lesson_path(lesson) if current_user.can_edit?(lesson.lecture)
+
     lesson_path(lesson)
   end
 end
diff --git a/app/helpers/media_helper.rb b/app/helpers/media_helper.rb
index 317c9eed6..a95385e85 100644
--- a/app/helpers/media_helper.rb
+++ b/app/helpers/media_helper.rb
@@ -32,6 +32,7 @@ def inspect_or_edit_medium_path(medium, inspection)
   # create text for notification about new medium in notification dropdown menu
   def medium_notification_item_header(medium)
     return unless medium.proper?
+
     t('notifications.new_medium_in') + medium.scoped_teachable_title
   end
 
@@ -45,6 +46,7 @@ def medium_notification_card_header(medium)
     if teachable.media_scope.class.to_s == 'Course'
       return teachable.media_scope.title_for_viewers
     end
+
     link_to(teachable.media_scope.title_for_viewers,
             medium.teachable.media_scope.path(current_user),
             class: 'text-dark')
@@ -63,14 +65,15 @@ def section_selection(medium)
 
   def preselected_sections(medium)
     return [] unless medium.teachable.class.to_s == 'Lesson'
+
     medium.teachable.sections.map(&:id)
   end
 
-
   def textcolor(medium)
     return '' if medium.visible?
     return 'locked' if medium.locked?
     return 'scheduled_release' if medium.publisher.present?
+
     'unpublished'
   end
 
@@ -78,6 +81,7 @@ def infotainment(medium)
     return 'nichts' unless medium.video || medium.manuscript
     return 'ein Video' unless medium.manuscript
     return 'ein Manuskript' unless medium.video
+
     'ein Video und ein Manuskript'
   end
 
@@ -85,16 +89,19 @@ def level_to_word(medium)
     return t('basics.not_set') unless medium.level.present?
     return t('basics.level_easy') if medium.level == 0
     return t('basics.level_medium') if medium.level == 1
+
     t('basics.level_hard')
   end
 
   def independent_to_word(medium)
     return t('basics.no_lc') unless medium.independent
+
     t('basics.yes_lc')
   end
 
   def medium_border(medium)
     return if medium.published? && !medium.locked?
+
     'border-danger'
   end
 
@@ -103,17 +110,19 @@ def media_sorts_select(purpose)
     return Medium.select_question if purpose == 'clicker'
     return add_prompt(Medium.select_importables) if purpose == 'import'
     return add_prompt(Medium.select_generic) if !current_user.admin?
+
     add_prompt(Medium.select_sorts)
   end
 
   def sort_preselect(purpose)
     return '' unless purpose == 'quiz'
+
     'Question'
   end
 
   def related_media_hash(references, media)
     media_list = references.map { |r| [r.medium, r.manuscript_link] } +
-                   media.zip(Array.new(media.size))
+                 media.zip(Array.new(media.size))
     hash = {}
     Medium.sort_enum.each do |s|
       media_in_s = media_list.select { |m| m.first.sort == s }
@@ -124,6 +133,7 @@ def related_media_hash(references, media)
 
   def release_date_info(medium)
     return unless medium.publisher.present?
+
     t('admin.medium.scheduled_for_release_short',
       release_date: I18n.l(medium.publisher&.release_date,
                            format: :long,
@@ -132,6 +142,7 @@ def release_date_info(medium)
 
   def edit_or_show_medium_path(medium)
     return edit_medium_path(medium) if current_user.can_edit?(medium)
+
     medium_path(medium)
   end
 
diff --git a/app/helpers/notifications_helper.rb b/app/helpers/notifications_helper.rb
index 8096b8447..74ff9883c 100644
--- a/app/helpers/notifications_helper.rb
+++ b/app/helpers/notifications_helper.rb
@@ -7,6 +7,7 @@ def notification_menu_item_header(notification)
     return medium_notification_item_header(notifiable) if notification.medium?
     return course_notification_item_header(notifiable) if notification.course?
     return lecture_notification_item_header(notifiable) if notification.lecture?
+
     announcement_notification_item_header(notifiable)
   end
 
@@ -18,6 +19,7 @@ def notification_menu_item_details(notification)
     if notification.lecture?
       return lecture_notification_item_details(notifiable)
     end
+
     ''
   end
 
@@ -26,6 +28,7 @@ def notification_color(notification)
     return 'bg-post-it-blue' if notification.generic_announcement?
     return 'bg-post-it-red' if notification.announcement?
     return 'bg-post-it-orange' if notification.course? || notification.lecture?
+
     'bg-post-it-yellow'
   end
 
@@ -33,14 +36,14 @@ def notification_color(notification)
   def notification_header(notification)
     notifiable = notification.notifiable
     text = if notification.medium?
-             medium_notification_card_header(notifiable)
-           elsif notification.course? || notification.lecture?
-             t('notifications.course_selection')
-           elsif notification.lecture_announcement?
-             announcement_notification_card_header(notifiable)
-           else
-             link_to t('mampf_news.title'), news_path, class: 'text-dark'
-           end
+      medium_notification_card_header(notifiable)
+    elsif notification.course? || notification.lecture?
+      t('notifications.course_selection')
+    elsif notification.lecture_announcement?
+      announcement_notification_card_header(notifiable)
+    else
+      link_to t('mampf_news.title'), news_path, class: 'text-dark'
+    end
     text.html_safe
   end
 
@@ -48,14 +51,14 @@ def notification_header(notification)
   def notification_text(notification)
     notifiable = notification.notifiable
     text = if notification.medium?
-             t('notifications.new_medium')
-           elsif notification.course?
-             course_notification_card_text(notifiable)
-           elsif notification.lecture?
-             lecture_notification_card_text(notifiable)
-           else
-             t('notifications.new_announcement')
-           end
+      t('notifications.new_medium')
+    elsif notification.course?
+      course_notification_card_text(notifiable)
+    elsif notification.lecture?
+      lecture_notification_card_text(notifiable)
+    else
+      t('notifications.new_announcement')
+    end
     text.html_safe
   end
 
@@ -63,21 +66,23 @@ def notification_text(notification)
   def notification_link(notification)
     notifiable = notification.notifiable
     return '' unless notifiable
+
     text = if notification.medium?
-             medium_notification_card_link(notifiable)
-           elsif notification.course?
-             course_notification_card_link
-           elsif notification.lecture?
-             lecture_notification_card_link
-           else
-             notifiable.details
-           end
+      medium_notification_card_link(notifiable)
+    elsif notification.course?
+      course_notification_card_link
+    elsif notification.lecture?
+      lecture_notification_card_link
+    else
+      notifiable.details
+    end
     text.html_safe
   end
 
   def items_card_size(small, comments_below)
     return '30vh' if comments_below
     return '60vh' if small
+
     '70vh'
   end
 end
diff --git a/app/helpers/referrals_helper.rb b/app/helpers/referrals_helper.rb
index 14d80fda3..fe8eef939 100644
--- a/app/helpers/referrals_helper.rb
+++ b/app/helpers/referrals_helper.rb
@@ -9,16 +9,19 @@ def teachable_selector(referral)
       return referral.medium.teachable&.media_scope&.selector_value
     end
     return 'external-0' if referral.item.sort == 'link'
+
     referral.item.medium.teachable&.media_scope&.selector_value
   end
 
   def show_link(referral)
     return true if referral.item.present? && referral.item.sort == 'link'
+
     false
   end
 
   def show_explanation(referral)
     return false if referral.item.nil?
+
     true
   end
 
@@ -28,15 +31,17 @@ def show_explanation(referral)
   def item_status_color(referral)
     return '' if referral.item.sort == 'link'
     if !referral.item_published? || referral.item_locked? ||
-         referral.item.quarantine
+       referral.item.quarantine
       return 'bg-post-it-pink'
     end
+
     ''
   end
 
   def item_status_color_value(referral)
     return 'white' if referral.item.sort == 'link'
     return '#fad1df' if !referral.item_published? || referral.item_locked?
+
     'white'
   end
 end
diff --git a/app/helpers/search_helper.rb b/app/helpers/search_helper.rb
index 91b5eea6c..e1e5d90c4 100644
--- a/app/helpers/search_helper.rb
+++ b/app/helpers/search_helper.rb
@@ -10,11 +10,13 @@ def plural_n(tags, filtered_tags)
 
   def hits_per_page(results_as_list)
     return [[10, 10], [20, 20], [50, 50]] if results_as_list
-    [[3,3],[4,4],[6,6], [12,12]]
+
+    [[3, 3], [4, 4], [6, 6], [12, 12]]
   end
 
   def default_hits_per_page(results_as_list)
     return 20 if results_as_list
+
     6
   end
 end
diff --git a/app/helpers/submissions_helper.rb b/app/helpers/submissions_helper.rb
index 78b89e8f0..b44505b31 100644
--- a/app/helpers/submissions_helper.rb
+++ b/app/helpers/submissions_helper.rb
@@ -2,6 +2,7 @@
 module SubmissionsHelper
   def cancel_editing_submission_path(submission)
     return cancel_edit_submission_path(submission) if submission.persisted?
+
     cancel_new_submission_path(params: { assignment_id: submission.assignment.id })
   end
 
@@ -14,49 +15,58 @@ def partner_preselection(user, lecture)
   end
 
   def admissible_invitee_selection(user, submission, lecture)
-  	submission.admissible_invitees(user).map { |u| [u.tutorial_name, u.id] }
+    submission.admissible_invitees(user).map { |u| [u.tutorial_name, u.id] }
   end
 
   def probable_invitee_ids(user, submission, lecture)
-  	partner_preselection(user, lecture) -
-  		(submission.users + submission.invited_users).map(&:id)
+    partner_preselection(user, lecture) -
+      (submission.users + submission.invited_users).map(&:id)
   end
 
   def invitations_possible?(submission, user)
-  	return false if submission.admissible_invitees(user).empty?
-  	return true unless submission.assignment.lecture.submission_max_team_size
-		submission.users.size <
-			submission.assignment.lecture.submission_max_team_size
+    return false if submission.admissible_invitees(user).empty?
+    return true unless submission.assignment.lecture.submission_max_team_size
+
+    submission.users.size <
+      submission.assignment.lecture.submission_max_team_size
   end
 
   def submission_color(submission, assignment)
-  	if assignment.active?
-  		return 'bg-submission-green' if submission&.manuscript
-  		return 'bg-submission-yellow' if submission
-  		return 'bg-submission-red'
-  	else
-  		return 'bg-submission-darker-green' if submission&.correction
+    if assignment.active?
+      return 'bg-submission-green' if submission&.manuscript
+      return 'bg-submission-yellow' if submission
+
+      return 'bg-submission-red'
+    else
+      return 'bg-submission-darker-green' if submission&.correction
+
       if submission&.manuscript && submission.too_late?
         return 'bg-submission-orange' if submission.accepted.nil?
         return 'bg-submission-green' if submission.accepted
+
         return 'bg-submission-red'
       end
-  		return 'bg-submission-green' if submission&.manuscript
-  		return 'bg-submission-red'
-  	end
+      return 'bg-submission-green' if submission&.manuscript
+
+      return 'bg-submission-red'
+    end
   end
 
   def submission_status_icon(submission, assignment)
     if assignment.active?
       return 'far fa-smile' if submission&.manuscript
+
       return 'fas fa-exclamation-triangle'
     else
       return 'far fa-smile' if submission&.correction
+
       if submission&.manuscript && submission.too_late?
         return 'fas fa-hourglass-start' if submission.accepted
+
         return 'fas fa-exclamation-triangle'
       end
       return 'fas fa-hourglass-start' if submission&.manuscript
+
       return 'fas fa-exclamation-triangle'
     end
   end
@@ -65,23 +75,27 @@ def submission_status_text(submission, assignment)
     if assignment.active?
       return t('submission.okay') if submission&.manuscript
       return t('submission.no_file') if submission
+
       return t('submission.nothing')
     else
       return t('submission.with_correction') if submission&.correction
+
       if submission&.manuscript && submission.too_late?
         return t('submission.too_late') if submission.accepted.nil?
         return t('submission.too_late_accepted') if submission.accepted
+
         return t('submission.too_late_rejected')
       end
       return t('submission.under_review') if submission&.manuscript
       return t('submission.no_file') if submission
+
       return t('submission.nothing')
     end
   end
 
   def submission_status(submission, assignment)
     tag.i class: [submission_status_icon(submission, assignment), 'fa-lg'],
-          data: { toggle: 'tooltip'},
+          data: { toggle: 'tooltip' },
           title: submission_status_text(submission, assignment)
   end
 
@@ -89,25 +103,29 @@ def show_submission_footer?(submission, assignment)
     return true if assignment.active?
     return false if assignment.totally_expired?
     return false if submission&.correction
+
     true
   end
 
   def submission_late_color(submission)
     return '' unless submission.too_late?
     return '' unless submission.accepted.nil?
+
     'bg-submission-orange'
   end
 
   def late_submission_info(submission, tutorial)
     text = t('submission.late')
     return text unless submission.accepted.nil? && current_user.in?(tutorial.tutors)
+
     "#{text} (#{t('tutorial.late_submission_decision')})"
   end
 
   def correction_display_mode(submission)
-  	accepted = submission.assignment.accepted_file_type
-  	non_inline = Assignment.non_inline_file_types
-  	return t('buttons.show') unless accepted.in?(non_inline)
-  	t('buttons.download')
+    accepted = submission.assignment.accepted_file_type
+    non_inline = Assignment.non_inline_file_types
+    return t('buttons.show') unless accepted.in?(non_inline)
+
+    t('buttons.download')
   end
-end
\ No newline at end of file
+end
diff --git a/app/helpers/talks_helper.rb b/app/helpers/talks_helper.rb
index be87e2625..3ef166bbf 100644
--- a/app/helpers/talks_helper.rb
+++ b/app/helpers/talks_helper.rb
@@ -7,16 +7,19 @@ def talk_positions_for_select(talk)
 
   def talk_card_color(talk, user)
     return 'bg-mdb-color-lighten-2' unless user.in?(talk.speakers)
+
     'bg-info'
   end
 
   def speaker_list(talk)
     return t('basics.tba') unless talk.speakers.present?
+
     talk.speakers.map(&:tutorial_name).join(', ')
   end
 
   def speaker_icon_class(talk)
     return 'fas fa-user' unless talk.speakers.count > 1
+
     'fas fa-users'
   end
 
@@ -39,4 +42,4 @@ def date_list(talk)
   def cospeaker_list(talk, user)
     (talk.speakers.to_a - [user]).map(&:tutorial_name).join(', ')
   end
-end
\ No newline at end of file
+end
diff --git a/app/helpers/tutorials_helper.rb b/app/helpers/tutorials_helper.rb
index da7657c1d..7cb929bf7 100644
--- a/app/helpers/tutorials_helper.rb
+++ b/app/helpers/tutorials_helper.rb
@@ -2,16 +2,18 @@
 module TutorialsHelper
   def cancel_editing_tutorial_path(tutorial)
     return cancel_edit_tutorial_path(tutorial) if tutorial.persisted?
+
     cancel_new_tutorial_path(params: { lecture: tutorial.lecture })
   end
 
   def tutorial_preselection(tutorial)
     return [[]] unless tutorial.persisted? && tutorial.tutors.any?
+
     options_for_select(tutorial.tutors.map { |t| [t.tutorial_info, t.id] },
                        tutorial.tutor_ids)
   end
 
   def tutorials_selection(lecture)
-  	lecture.tutorials.map { |t| [t.title_with_tutors, t.id] }
+    lecture.tutorials.map { |t| [t.title_with_tutors, t.id] }
   end
 end
diff --git a/app/helpers/vertices_helper.rb b/app/helpers/vertices_helper.rb
index 5ce17d3dc..db0401c48 100644
--- a/app/helpers/vertices_helper.rb
+++ b/app/helpers/vertices_helper.rb
@@ -12,4 +12,4 @@ def vertices_labels(quiz, vertex_id, undefined)
   def crosses_id(crosses)
     crosses.keys.collect { |k| [k, crosses[k].to_s.first] }.flatten.join
   end
-end
\ No newline at end of file
+end
diff --git a/app/mailers/application_mailer.rb b/app/mailers/application_mailer.rb
index 13fdba3ff..d8255248e 100644
--- a/app/mailers/application_mailer.rb
+++ b/app/mailers/application_mailer.rb
@@ -1,6 +1,8 @@
 class ApplicationMailer < ActionMailer::Base
   helper EmailHelper
   default from: DefaultSetting::PROJECT_EMAIL
-  default "Message-ID" => -> {"<#{rand.to_s.split('.')[1]}.#{Time.now.to_i}@#{ENV['MAILID_DOMAIN']}>" }
+  default "Message-ID" => -> {
+                            "<#{rand.to_s.split('.')[1]}.#{Time.now.to_i}@#{ENV['MAILID_DOMAIN']}>"
+                          }
   layout 'mailer'
 end
diff --git a/app/mailers/exception_handler/exception_mailer.rb b/app/mailers/exception_handler/exception_mailer.rb
index dfe09b2aa..aa1913e52 100644
--- a/app/mailers/exception_handler/exception_mailer.rb
+++ b/app/mailers/exception_handler/exception_mailer.rb
@@ -1,6 +1,5 @@
 module ExceptionHandler
   class ExceptionMailer < ActionMailer::Base
-
     # Layout
     layout "exception_mailer"
 
@@ -17,4 +16,4 @@ def new_exception e
       Rails.logger.info "Exception Sent To → #{ExceptionHandler.config.email}"
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/mailers/mathi_mailer.rb b/app/mailers/mathi_mailer.rb
index f55eeb203..438fbe30e 100644
--- a/app/mailers/mathi_mailer.rb
+++ b/app/mailers/mathi_mailer.rb
@@ -4,6 +4,7 @@ class MathiMailer < ApplicationMailer
 
   def ghost_email(user)
     return if user.ghost_hash.nil?
+
     @name = user.name
     @hash = user.ghost_hash
     mail(to: user.email, subject: t('mailer.hash_mail_subject'))
@@ -17,7 +18,8 @@ def data_request_email(user)
 
   def data_provide_email(user)
     @user = user
-    mail(to: user.email, subject: t('mailer.data_provide_mail_subject')) do |format|
+    mail(to: user.email,
+         subject: t('mailer.data_provide_mail_subject')) do |format|
       format.html { render layout: 'mailer' }
     end
   end
diff --git a/app/mailers/my_mailer.rb b/app/mailers/my_mailer.rb
index 160ad930e..c57e0eb04 100644
--- a/app/mailers/my_mailer.rb
+++ b/app/mailers/my_mailer.rb
@@ -4,6 +4,8 @@ class MyMailer < Devise::Mailer
   layout "devise_mailer"
   default template_path: 'devise/mailer' # to make sure that your mailer uses the devise views
   default from: DefaultSetting::PROJECT_EMAIL
-  default "Message-ID" => -> {"<#{rand.to_s.split('.')[1]}.#{Time.now.to_i}@#{ENV['MAILID_DOMAIN']}>" }
+  default "Message-ID" => -> {
+                            "<#{rand.to_s.split('.')[1]}.#{Time.now.to_i}@#{ENV['MAILID_DOMAIN']}>"
+                          }
   helper EmailHelper
 end
diff --git a/app/mailers/notification_mailer.rb b/app/mailers/notification_mailer.rb
index 3f8d6eab4..03a4419b0 100644
--- a/app/mailers/notification_mailer.rb
+++ b/app/mailers/notification_mailer.rb
@@ -22,7 +22,6 @@ class NotificationMailer < ApplicationMailer
                 only: [:submission_join_email,
                        :submission_leave_email]
 
-
   def medium_email
     @medium = params[:medium]
     mail(from: @sender,
@@ -34,11 +33,11 @@ def medium_email
   def announcement_email
     @announcement = params[:announcement]
     @announcement_details = if @announcement.lecture.present?
-                             t('in') + ' ' +
-                               @announcement.lecture.title_for_viewers
-                            else
-                              t('mailer.mampf_news')
-                            end
+      t('in') + ' ' +
+        @announcement.lecture.title_for_viewers
+    else
+      t('mailer.mampf_news')
+    end
     mail(from: @sender,
          bcc: @recipients.pluck(:email),
          subject: t('mailer.announcement_subject') + ' ' +
@@ -50,9 +49,9 @@ def new_lecture_email
     mail(from: @sender,
          bcc: @recipients.pluck(:email),
          subject: t('mailer.new_lecture_subject',
-         title: @lecture.title_for_viewers))
+                    title: @lecture.title_for_viewers))
   end
-  
+
   def new_editor_email
     @lecture = params[:lecture]
     @recipient = params[:recipient]
@@ -61,9 +60,9 @@ def new_editor_email
     mail(from: @sender,
          to: @recipient.email,
          subject: t('mailer.new_editor_subject',
-         title: @lecture.title_for_viewers))
+                    title: @lecture.title_for_viewers))
   end
-  
+
   def submission_invitation_email
     @recipient = params[:recipient]
     @assignment = params[:assignment]
@@ -177,26 +176,26 @@ def submission_destruction_lecture_email
 
   private
 
-  def set_sender_and_locale
-    @sender = "#{t('mailer.notification')} <#{DefaultSetting::PROJECT_NOTIFICATION_EMAIL}>"
-    I18n.locale = params[:locale]
-  end
+    def set_sender_and_locale
+      @sender = "#{t('mailer.notification')} <#{DefaultSetting::PROJECT_NOTIFICATION_EMAIL}>"
+      I18n.locale = params[:locale]
+    end
 
-  def set_recipients
-    @recipients = User.where(id: params[:recipients])
-  end
+    def set_recipients
+      @recipients = User.where(id: params[:recipients])
+    end
 
-  def set_recipient_and_submission
-    @recipient = params[:recipient]
-    @submission = params[:submission]
-    @assignment = @submission.assignment
-  end
+    def set_recipient_and_submission
+      @recipient = params[:recipient]
+      @submission = params[:submission]
+      @assignment = @submission.assignment
+    end
 
-  def set_filename
-    @filename = params[:filename]
-  end
+    def set_filename
+      @filename = params[:filename]
+    end
 
-  def set_user
-    @user = params[:user]
-  end
+    def set_user
+      @user = params[:user]
+    end
 end
diff --git a/app/models/ability.rb b/app/models/ability.rb
index b96221856..fbf76c958 100644
--- a/app/models/ability.rb
+++ b/app/models/ability.rb
@@ -8,4 +8,4 @@ class Ability
 
   def initialize(user)
   end
-end
\ No newline at end of file
+end
diff --git a/app/models/announcement.rb b/app/models/announcement.rb
index 43d7bc56e..04d8eae44 100644
--- a/app/models/announcement.rb
+++ b/app/models/announcement.rb
@@ -8,7 +8,7 @@ class Announcement < ApplicationRecord
 
   paginates_per 10
 
-  scope :active_on_main, -> { where(on_main_page: true, lecture:nil) }
+  scope :active_on_main, -> { where(on_main_page: true, lecture: nil) }
 
   # does there (still) exist a notification for the announcement for
   # the given user
diff --git a/app/models/answer.rb b/app/models/answer.rb
index 4af1f90cf..7bc2403a1 100644
--- a/app/models/answer.rb
+++ b/app/models/answer.rb
@@ -12,6 +12,7 @@ def conditional_explanation(correct)
     unless correct
       return explanation.string_between_markers(':(inkorrekt:', ')')
     end
+
     explanation.string_between_markers('(korrekt:', '):')
   end
 
@@ -26,24 +27,24 @@ def text_join
 
   private
 
-  def question_not_orphaned?
-    throw(:abort) if question.answers.size == 1
-    true
-  end
+    def question_not_orphaned?
+      throw(:abort) if question.answers.size == 1
+      true
+    end
 
-  def update_quizzes
-    question.quiz_ids.each do |q|
-      quiz = Quiz.find(q)
-      quiz_graph = quiz.quiz_graph
-      vertices = quiz_graph.find_vertices(question)
-      vertices.each do |v|
-        quiz_graph.reset_vertex_answers_change(v)
+    def update_quizzes
+      question.quiz_ids.each do |q|
+        quiz = Quiz.find(q)
+        quiz_graph = quiz.quiz_graph
+        vertices = quiz_graph.find_vertices(question)
+        vertices.each do |v|
+          quiz_graph.reset_vertex_answers_change(v)
+        end
+        quiz.update(quiz_graph: quiz_graph)
       end
-      quiz.update(quiz_graph: quiz_graph)
     end
-  end
 
-  def touch_medium
-    question.becomes(Medium).update(updated_at: Time.now)
-  end
+    def touch_medium
+      question.becomes(Medium).update(updated_at: Time.now)
+    end
 end
diff --git a/app/models/assignment.rb b/app/models/assignment.rb
index 6ad38bdb6..0da21a6ad 100644
--- a/app/models/assignment.rb
+++ b/app/models/assignment.rb
@@ -30,9 +30,9 @@ def self.accepted_file_types
             inclusion: { in: Assignment.accepted_file_types }
 
   def submission(user)
-  	UserSubmissionJoin.where(submission: Submission.where(assignment: self),
-  													 user: user)
-  									 &.first&.submission
+    UserSubmissionJoin.where(submission: Submission.where(assignment: self),
+                             user: user)
+                     &.first&.submission
   end
 
   def submitter_ids
@@ -52,7 +52,7 @@ def semiactive?
   end
 
   def expired?
-  	!active?
+    !active?
   end
 
   def totally_expired?
@@ -65,27 +65,30 @@ def in_grace_period?
 
   def friendly_deadline
     return deadline unless lecture.submission_grace_period
+
     deadline + lecture.submission_grace_period.minutes
   end
 
   def current?
-  	self.in?(lecture.current_assignments)
+    self.in?(lecture.current_assignments)
   end
 
   def previous?
-  	self.in?(lecture.previous_assignments)
+    self.in?(lecture.previous_assignments)
   end
 
   def previous
     siblings = lecture.assignments_by_deadline
     position = siblings.map(&:first).find_index(deadline)
     return unless position.positive?
+
     siblings[position - 1].second
   end
 
   def submission_partners(user)
     submission = submission(user)
     return unless submission
+
     submission.users - [user]
   end
 
@@ -94,16 +97,17 @@ def tutorial(user)
   end
 
   def destructible?
-  	submissions.proper.none?
+    submissions.proper.none?
   end
 
   def check_destructibility
-  	throw(:abort) unless destructible?
-  	true
+    throw(:abort) unless destructible?
+    true
   end
 
   def has_documents?
     return false unless medium
+
     medium.video || medium.manuscript || medium.geogebra ||
       medium.external_reference_link.present? ||
       (medium.sort == 'Quiz' && medium.quiz_graph)
@@ -141,12 +145,12 @@ def accepted_mime_types
   # is set to .tar.gz
   # see e.g. https://bugs.chromium.org/p/chromium/issues/detail?id=521781
   def accepted_for_file_input
-  	return accepted_file_type unless accepted_file_type == '.tar.gz'
-  	'.gz'
+    return accepted_file_type unless accepted_file_type == '.tar.gz'
+
+    '.gz'
   end
 
   def localized_deletion_date
     deletion_date.strftime(I18n.t('date.formats.concise'))
   end
-  
 end
diff --git a/app/models/chapter.rb b/app/models/chapter.rb
index 6841ff5e3..cad5d882c 100644
--- a/app/models/chapter.rb
+++ b/app/models/chapter.rb
@@ -16,13 +16,15 @@ def to_label
                     number: displayed_number,
                     title: title)
     end
-    I18n.t("hidden_#{lecture.chapter_name}", number: displayed_number, title: title)
+    I18n.t("hidden_#{lecture.chapter_name}", number: displayed_number,
+                                             title: title)
   end
 
   # Returns the number of the chapter. Unless the user explicitly specified
   # a display number, this number is calculated
   def displayed_number
     return calculated_number unless display_number.present?
+
     display_number
   end
 
@@ -35,6 +37,7 @@ def reference
   # Returns the chapter number based on the position in the chapters list.
   def calculated_number
     return position.to_s unless lecture.start_chapter.present?
+
     (lecture.start_chapter + position - 1).to_s
   end
 
diff --git a/app/models/clicker.rb b/app/models/clicker.rb
index 13742f271..075918d04 100644
--- a/app/models/clicker.rb
+++ b/app/models/clicker.rb
@@ -36,14 +36,15 @@ def close!
   def results
     total = votes.count
     return unless total.positive?
+
     (1..alternatives).map { |i| votes.where(value: i).count / total.to_f }
                      .map { |x| (100 * x).round }
   end
 
   private
 
-  def set_basics
-    self.code = SecureRandom.uuid
-    self.alternatives = 3
-  end
+    def set_basics
+      self.code = SecureRandom.uuid
+      self.alternatives = 3
+    end
 end
diff --git a/app/models/clicker_vote.rb b/app/models/clicker_vote.rb
index 6c6a06046..8d73c024c 100644
--- a/app/models/clicker_vote.rb
+++ b/app/models/clicker_vote.rb
@@ -7,14 +7,15 @@ class ClickerVote < ApplicationRecord
 
   private
 
-  def clicker_open
-    return true if clicker.open?
-    errors.add(:clicker, :clicker_closed)
-  end
+    def clicker_open
+      return true if clicker.open?
 
-  def value_in_range
-    return true if value.in?(1..clicker.alternatives)
-    errors.add(:value, :out_of_range)
-  end
-end
+      errors.add(:clicker, :clicker_closed)
+    end
+
+    def value_in_range
+      return true if value.in?(1..clicker.alternatives)
 
+      errors.add(:value, :out_of_range)
+    end
+end
diff --git a/app/models/course_self_join.rb b/app/models/course_self_join.rb
index 0353e1c48..7311f85eb 100644
--- a/app/models/course_self_join.rb
+++ b/app/models/course_self_join.rb
@@ -5,14 +5,14 @@
 class CourseSelfJoin < ApplicationRecord
   belongs_to :course
   belongs_to :preceding_course, class_name: 'Course'
-  validates :preceding_course, uniqueness: { scope: :course}
+  validates :preceding_course, uniqueness: { scope: :course }
 
   # we do not allow a course to be preceding itself
   after_save :destroy, if: :self_inverse?
 
   private
 
-  def self_inverse?
-    course_id == preceding_course_id
-  end
+    def self_inverse?
+      course_id == preceding_course_id
+    end
 end
diff --git a/app/models/course_tag_join.rb b/app/models/course_tag_join.rb
index d97f91449..92a30f4e2 100644
--- a/app/models/course_tag_join.rb
+++ b/app/models/course_tag_join.rb
@@ -12,8 +12,9 @@ class CourseTagJoin < ApplicationRecord
 
   private
 
-  def touch_tag
-    return unless tag.present? && tag.persisted?
-    tag.touch
-  end
+    def touch_tag
+      return unless tag.present? && tag.persisted?
+
+      tag.touch
+    end
 end
diff --git a/app/models/division.rb b/app/models/division.rb
index 148b5b9c6..bab3b37ce 100644
--- a/app/models/division.rb
+++ b/app/models/division.rb
@@ -3,12 +3,12 @@ class Division < ApplicationRecord
   has_many :division_course_joins
   has_many :courses, through: :division_course_joins
 
-	translates :name
+  translates :name
 
-	globalize_accessors locales: I18n.available_locales,
-											attributes: translated_attribute_names
+  globalize_accessors locales: I18n.available_locales,
+                      attributes: translated_attribute_names
 
-	def name_with_program
-		"#{program.subject.name}:#{program.name}:#{name}"
-	end
+  def name_with_program
+    "#{program.subject.name}:#{program.name}:#{name}"
+  end
 end
diff --git a/app/models/interaction.rb b/app/models/interaction.rb
index 652ea675b..774e8e794 100644
--- a/app/models/interaction.rb
+++ b/app/models/interaction.rb
@@ -1,17 +1,19 @@
 class Interaction < InteractionsRecord
-
-  scope :created_between, lambda {|start_date, end_date| where(created_at: start_date.beginning_of_day..end_date.end_of_day)}
+  scope :created_between, lambda { |start_date, end_date|
+                            where(created_at: start_date.beginning_of_day..end_date.end_of_day)
+                          }
   require 'csv'
 
   def self.to_csv
-    attributes = %w{id session_id created_at full_path referrer_url study_participant}
+    attributes = %w{id session_id created_at full_path referrer_url
+                    study_participant}
 
     CSV.generate(headers: true) do |csv|
       csv << attributes
 
       all.each do |interaction|
-        csv << attributes.map{ |attr| interaction.send(attr) }
+        csv << attributes.map { |attr| interaction.send(attr) }
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/models/interactions_record.rb b/app/models/interactions_record.rb
index d832e6d7b..77ae77892 100644
--- a/app/models/interactions_record.rb
+++ b/app/models/interactions_record.rb
@@ -2,4 +2,4 @@ class InteractionsRecord < ApplicationRecord
   self.abstract_class = true
 
   connects_to database: { writing: :interactions, reading: :interactions }
-end
\ No newline at end of file
+end
diff --git a/app/models/item.rb b/app/models/item.rb
index ab01fce53..bef489836 100644
--- a/app/models/item.rb
+++ b/app/models/item.rb
@@ -62,6 +62,7 @@ class Item < ApplicationRecord
   def end_time
     return unless video?
     return TimeStamp.new(total_seconds: medium.video_duration) if next_item.nil?
+
     TimeStamp.new(total_seconds: next_item.start_time.total_seconds - 0.001)
   end
 
@@ -79,6 +80,7 @@ def vtt_time_span
   def vtt_text
     return '' if sort == 'pdf_destination'
     return description if sort == 'link'
+
     short_description
   end
 
@@ -88,6 +90,7 @@ def vtt_text
   # "Bem. 29.13: zu freien Moduln\n\n"
   def vtt_reference
     return short_description + "\n\n" unless short_reference.present?
+
     short_reference + ': ' + short_description + "\n\n"
   end
 
@@ -97,6 +100,7 @@ def vtt_reference
   # "Verweis auf LA 2 SS 17, Bem. 29.13:"
   def vtt_meta_reference(referring_medium)
     return I18n.t('item.external_reference') if sort == 'link'
+
     ref = local?(referring_medium) ? short_reference : long_reference
     I18n.t('item.internal_reference', ref: ref)
   end
@@ -106,6 +110,7 @@ def vtt_meta_reference(referring_medium)
   #  "Bem. 29.13"
   def short_reference
     return math_reference if math_items.include?(sort)
+
     toc_reference
   end
 
@@ -116,6 +121,7 @@ def long_reference
     return short_reference if sort.in?(['self', 'link'])
     return short_ref_with_teachable if section.present?
     return medium.title_for_viewers unless short_reference.present?
+
     medium.title_for_viewers + ', ' + short_reference
   end
 
@@ -124,6 +130,7 @@ def long_reference
   def short_description
     return section.title if sort == 'section' && section.present?
     return medium.title_for_viewers if sort == 'self'
+
     description.to_s
   end
 
@@ -136,6 +143,7 @@ def short_description
   def local_reference
     unless sort.in?(['self', 'link', 'pdf_destination'])
       return short_ref_with_description unless medium&.sort == 'Script'
+
       return 'Skript, ' + short_ref_with_description
     end
     local_non_math_reference
@@ -148,6 +156,7 @@ def title_within_course
     return '' unless medium.present? && medium.proper?
     return local_reference if medium.teachable_type == 'Course'
     return local_reference unless medium.teachable.media_scope.term
+
     medium.teachable.media_scope.term.to_label_short + ', ' + local_reference
   end
 
@@ -165,23 +174,26 @@ def title_within_lecture
   # lesson's lecture
   def local?(referring_medium)
     return false unless section.present?
+
     in?(referring_medium.teachable.lecture&.items.to_a)
   end
 
   # background color of different item sorts within thyme editor
   def background
     return '#70db70;' if ['remark', 'theorem', 'lemma', 'corollary',
-                       'algorithm', 'Theorem', 'Corollary', 'Lemma',
-                       'proposition'].include?(sort)
+                          'algorithm', 'Theorem', 'Corollary', 'Lemma',
+                          'proposition'].include?(sort)
     return '#75d7f0;' if ['definition', 'annotation', 'example',
                           'figure', 'exercise', 'equation'].include?(sort)
     return 'lightgray;' if sort == 'link' || sort == 'self'
+
     ''
   end
 
   # special background for sections
   def section_background
     return 'beige;' if sort == 'section'
+
     'aliceblue;'
   end
 
@@ -193,6 +205,7 @@ def video_link
     return if sort == 'pdf_destination'
     return unless video?
     return video_link_untimed if sort == 'self'
+
     video_link_timed
   end
 
@@ -206,23 +219,25 @@ def manuscript_link
     return unless manuscript?
     return manuscript_link_destination if pdf_destination.present?
     return manuscript_link_page if page.present?
+
     manuscript_link_generic
   end
 
   def quiz_link
     return unless quiz?
+
     return quiz_link_generic
   end
 
-
   # if the associated medium contains an external link, it is returned
   def medium_link
     return unless medium_link?
+
     medium.external_reference_link
   end
 
   def self.available_sorts
-    ['definition','remark', 'lemma', 'theorem', 'example', 'annotation',
+    ['definition', 'remark', 'lemma', 'theorem', 'example', 'annotation',
      'algorithm', 'corollary', 'section', 'label', 'subsection', 'Theorem',
      'proposition', 'Lemma', 'Corollary', 'figure', 'chapter', 'exercise',
      'equation']
@@ -285,190 +300,205 @@ def related_items_visible?
 
   private
 
-  def math_items
-    ['remark', 'theorem', 'lemma', 'definition', 'annotation', 'example',
-     'corollary', 'algorithm', 'Theorem', 'proposition', 'Lemma', 'Corollary',
-     'figure', 'subsection', 'exercise', 'equation']
-  end
+    def math_items
+      ['remark', 'theorem', 'lemma', 'definition', 'annotation', 'example',
+       'corollary', 'algorithm', 'Theorem', 'proposition', 'Lemma', 'Corollary',
+       'figure', 'subsection', 'exercise', 'equation']
+    end
 
-  def other_items
-    ['section', 'self', 'link', 'label', 'pdf_destination', 'chapter']
-  end
+    def other_items
+      ['section', 'self', 'link', 'label', 'pdf_destination', 'chapter']
+    end
 
-  def proper_link?
-    sort == 'link' && link.present?
-  end
+    def proper_link?
+      sort == 'link' && link.present?
+    end
 
-  def next_item
-    medium.proper_items_by_time.find do |i|
-      i.start_time.total_seconds > start_time.total_seconds
+    def next_item
+      medium.proper_items_by_time.find do |i|
+        i.start_time.total_seconds > start_time.total_seconds
+      end
     end
-  end
 
-  def sort_long
-    I18n.t("admin.item.sort_short.#{sort}")
-  end
+    def sort_long
+      I18n.t("admin.item.sort_short.#{sort}")
+    end
 
-  # the next methods are used to put together the references and descriptions
+    # the next methods are used to put together the references and descriptions
 
-  def math_item_number
-    ref_number.to_s
-  end
+    def math_item_number
+      ref_number.to_s
+    end
 
-  def math_reference
-    sort_long + ' ' + math_item_number
-  end
+    def math_reference
+      sort_long + ' ' + math_item_number
+    end
 
-  def special_reference
-    return 'Medium' if sort == 'self'
-    return '' if sort == 'pdf_destination'
-    'extern'
-  end
+    def special_reference
+      return 'Medium' if sort == 'self'
+      return '' if sort == 'pdf_destination'
 
-  def section_reference
-    return section.displayed_number.to_s if section.present?
-    return '§' + ref_number if ref_number.present?
-    ''
-  end
+      'extern'
+    end
 
-  def chapter_reference
-    chapter_short = I18n.t('admin.item.chapter_short',
-                           locale: locale)
-    return "#{chapter_short} #{ref_number}" if ref_number.present?
-    chapter_short
-  end
+    def section_reference
+      return section.displayed_number.to_s if section.present?
+      return '§' + ref_number if ref_number.present?
 
-  def toc_reference
-    return section_reference if sort == 'section'
-    return chapter_reference if sort == 'chapter'
-    if sort == 'label'
-      return '' if description.present?
-      return 'destination: ' + pdf_destination.to_s
+      ''
     end
-    special_reference
-  end
 
-  def non_math_reference
-    return medium.title_for_viewers if sort == 'self'
-    if sort == 'pdf_destination'
-      return medium.title_for_viewers + ' (pdf) # ' + description
+    def chapter_reference
+      chapter_short = I18n.t('admin.item.chapter_short',
+                             locale: locale)
+      return "#{chapter_short} #{ref_number}" if ref_number.present?
+
+      chapter_short
     end
-    'extern ' + description.to_s if sort == 'link'
-  end
 
-  def local_non_math_reference
-    return medium.local_title_for_viewers if sort == 'self'
-    if sort == 'pdf_destination'
-      return medium.local_title_for_viewers + ' (pdf) # ' + description
+    def toc_reference
+      return section_reference if sort == 'section'
+      return chapter_reference if sort == 'chapter'
+
+      if sort == 'label'
+        return '' if description.present?
+
+        return 'destination: ' + pdf_destination.to_s
+      end
+      special_reference
     end
-    'extern ' + description.to_s if sort == 'link'
-  end
 
-  def short_ref_with_teachable
-    unless short_reference.present?
-      return medium.teachable.lecture.title_for_viewers
+    def non_math_reference
+      return medium.title_for_viewers if sort == 'self'
+      if sort == 'pdf_destination'
+        return medium.title_for_viewers + ' (pdf) # ' + description
+      end
+
+      'extern ' + description.to_s if sort == 'link'
     end
-    medium.teachable.lecture.title_for_viewers + ', ' + short_reference
-  end
 
-  def short_ref_with_description
-    return short_reference + ' ' + description.to_s unless sort == 'section'
-    short_ref_for_sections
-  end
+    def local_non_math_reference
+      return medium.local_title_for_viewers if sort == 'self'
+      if sort == 'pdf_destination'
+        return medium.local_title_for_viewers + ' (pdf) # ' + description
+      end
 
-  def short_ref_for_sections
-    return short_reference + ' ' + description if description.present?
-    return short_reference + ' ' + section.title if section.present?
-    short_reference
-  end
+      'extern ' + description.to_s if sort == 'link'
+    end
 
-  # the next two methods get video links using helper methods
+    def short_ref_with_teachable
+      unless short_reference.present?
+        return medium.teachable.lecture.title_for_viewers
+      end
 
-  def video_link_untimed
-    Rails.application.routes.url_helpers.play_medium_path(medium.id)
-  end
+      medium.teachable.lecture.title_for_viewers + ', ' + short_reference
+    end
 
-  def video_link_timed
-    Rails.application.routes.url_helpers
-         .play_medium_path(medium.id, time: start_time.total_seconds)
-  end
+    def short_ref_with_description
+      return short_reference + ' ' + description.to_s unless sort == 'section'
 
-  def manuscript_link_generic
-    Rails.application.routes.url_helpers.display_medium_path(medium.id)
-  end
+      short_ref_for_sections
+    end
 
-  def manuscript_link_destination
-    Rails.application.routes.url_helpers
-         .display_medium_path(medium.id, destination: pdf_destination)
-  end
+    def short_ref_for_sections
+      return short_reference + ' ' + description if description.present?
+      return short_reference + ' ' + section.title if section.present?
 
-  def manuscript_link_page
-    Rails.application.routes.url_helpers
-         .display_medium_path(medium.id, page: page)
-  end
+      short_reference
+    end
 
-  def quiz_link_generic
-    Rails.application.routes.url_helpers.take_quiz_path(medium.id)
-  end
+    # the next two methods get video links using helper methods
 
-  # the next methods are used for validations
+    def video_link_untimed
+      Rails.application.routes.url_helpers.play_medium_path(medium.id)
+    end
 
-  def valid_start_time
-    return true if start_time.nil?
-    return true if start_time.valid?
-    errors.add(:start_time, :invalid_format)
-    false
-  end
+    def video_link_timed
+      Rails.application.routes.url_helpers
+           .play_medium_path(medium.id, time: start_time.total_seconds)
+    end
 
-  def start_time_not_required
-    medium.nil? || medium.sort == 'Script' || sort == 'self' ||
-      sort == 'pdf_destination' || !start_time&.valid? || !medium.video
-  end
+    def manuscript_link_generic
+      Rails.application.routes.url_helpers.display_medium_path(medium.id)
+    end
 
-  def start_time_not_too_late
-    return true if start_time_not_required
-    return true if start_time.total_seconds <= medium.video.metadata['duration']
-    errors.add(:start_time, :too_late)
-    false
-  end
+    def manuscript_link_destination
+      Rails.application.routes.url_helpers
+           .display_medium_path(medium.id, destination: pdf_destination)
+    end
 
-  def start_times_without
-    (medium.proper_items - [self]).map do |i|
-      [i.start_time.floor_seconds, i.start_time.milliseconds]
+    def manuscript_link_page
+      Rails.application.routes.url_helpers
+           .display_medium_path(medium.id, page: page)
     end
-  end
 
-  def no_duplicate_start_time
-    return true if start_time_not_required
-    if start_times_without.include?([start_time.floor_seconds,
-                                     start_time.milliseconds])
-      errors.add(:start_time, :taken)
+    def quiz_link_generic
+      Rails.application.routes.url_helpers.take_quiz_path(medium.id)
+    end
+
+    # the next methods are used for validations
+
+    def valid_start_time
+      return true if start_time.nil?
+      return true if start_time.valid?
+
+      errors.add(:start_time, :invalid_format)
       false
     end
-    true
-  end
 
-  def nonempty_link_or_explanation
-    return true if sort != 'link'
-    return true if link.present?
-    return true if explanation.present?
-    errors.add(:link, :blank)
-    errors.add(:explanation, :blank)
-  end
+    def start_time_not_required
+      medium.nil? || medium.sort == 'Script' || sort == 'self' ||
+        sort == 'pdf_destination' || !start_time&.valid? || !medium.video
+    end
 
-  # is used for after save and before destroy callbacks
-  def touch_medium
-    return unless medium.present? && medium.persisted?
-    medium.touch
-  end
+    def start_time_not_too_late
+      return true if start_time_not_required
+      return true if start_time.total_seconds <= medium.video.metadata['duration']
 
-  # simulates the after_destroy callback for item_self_joins
-  def destroy_joins(related_item)
-    ItemSelfJoin.where(item: [self, related_item],
-                       related_item: [self, related_item]).delete_all
-  end
+      errors.add(:start_time, :too_late)
+      false
+    end
 
-  def locale
-    medium&.locale || I18n.default_locale
-  end
+    def start_times_without
+      (medium.proper_items - [self]).map do |i|
+        [i.start_time.floor_seconds, i.start_time.milliseconds]
+      end
+    end
+
+    def no_duplicate_start_time
+      return true if start_time_not_required
+
+      if start_times_without.include?([start_time.floor_seconds,
+                                       start_time.milliseconds])
+        errors.add(:start_time, :taken)
+        false
+      end
+      true
+    end
+
+    def nonempty_link_or_explanation
+      return true if sort != 'link'
+      return true if link.present?
+      return true if explanation.present?
+
+      errors.add(:link, :blank)
+      errors.add(:explanation, :blank)
+    end
+
+    # is used for after save and before destroy callbacks
+    def touch_medium
+      return unless medium.present? && medium.persisted?
+
+      medium.touch
+    end
+
+    # simulates the after_destroy callback for item_self_joins
+    def destroy_joins(related_item)
+      ItemSelfJoin.where(item: [self, related_item],
+                         related_item: [self, related_item]).delete_all
+    end
+
+    def locale
+      medium&.locale || I18n.default_locale
+    end
 end
diff --git a/app/models/item_self_join.rb b/app/models/item_self_join.rb
index be448bacc..8f03219d2 100644
--- a/app/models/item_self_join.rb
+++ b/app/models/item_self_join.rb
@@ -16,32 +16,33 @@ class ItemSelfJoin < ApplicationRecord
 
   private
 
-  def create_inverse
-    self.class.create(inverse_relation_options)
-  end
-
-  def destroy_inverses
-    inverses.destroy_all
-  end
-
-  def self_inverse?
-    item_id == related_item_id
-  end
-
-  def inverse?
-    self.class.exists?(inverse_relation_options) || self_inverse?
-  end
-
-  def inverses
-    self.class.where(inverse_relation_options)
-  end
-
-  def inverse_relation_options
-    { related_item_id: item_id, item_id: related_item_id }
-  end
-
-  def touch_item
-    return if item.nil?
-    item.touch
-  end
+    def create_inverse
+      self.class.create(inverse_relation_options)
+    end
+
+    def destroy_inverses
+      inverses.destroy_all
+    end
+
+    def self_inverse?
+      item_id == related_item_id
+    end
+
+    def inverse?
+      self.class.exists?(inverse_relation_options) || self_inverse?
+    end
+
+    def inverses
+      self.class.where(inverse_relation_options)
+    end
+
+    def inverse_relation_options
+      { related_item_id: item_id, item_id: related_item_id }
+    end
+
+    def touch_item
+      return if item.nil?
+
+      item.touch
+    end
 end
diff --git a/app/models/lecture.rb b/app/models/lecture.rb
index 4f510aecf..c8326b500 100644
--- a/app/models/lecture.rb
+++ b/app/models/lecture.rb
@@ -16,9 +16,9 @@ class Lecture < ApplicationRecord
 
   # during the term, a lot of lessons take place for this lecture
   has_many :lessons, -> { order(date: :asc, id: :asc) },
-                     dependent: :destroy,
-                     after_add: :touch_siblings,
-                     after_remove: :touch_siblings
+           dependent: :destroy,
+           after_add: :touch_siblings,
+           after_remove: :touch_siblings
 
   # a lecture has many talks, which have positions
   has_many :talks, -> { order(position: :asc) }, dependent: :destroy
@@ -37,7 +37,7 @@ class Lecture < ApplicationRecord
   # a lecture has many users who have starred it (fans)
   has_many :user_favorite_lecture_joins, dependent: :destroy
   has_many :fans, -> { distinct }, through: :user_favorite_lecture_joins,
-           source: :user
+                                   source: :user
 
   # a lecture has many editors
   # these are users different from the teacher who have the right to
@@ -84,7 +84,6 @@ class Lecture < ApplicationRecord
                             greater_than: -1 },
             allow_nil: true
 
-
   # as a teacher has editing rights by definition, we do not need him in the
   # list of editors
   after_save :remove_teacher_as_editor
@@ -161,11 +160,13 @@ def selector_value
 
   def title
     return course.title unless term
+
     "(#{sort_localized_short}) #{course.title}, #{term.to_label}"
   end
 
   def title_no_term
     return course.title unless term
+
     "(#{sort_localized_short}) #{course.title}"
   end
 
@@ -179,6 +180,7 @@ def to_label
 
   def compact_title
     return course.compact_title unless term
+
     "#{sort_localized_short}.#{course.compact_title}.#{term.compact_title}"
   end
 
@@ -202,6 +204,7 @@ def card_header
 
   def card_header_path(user)
     return unless user.lectures.include?(self)
+
     lecture_path
   end
 
@@ -218,6 +221,7 @@ def visible_for_user?(user)
     return true if edited_by?(user)
     return false unless published?
     return false if restricted? && !self.in?(user.lectures)
+
     true
   end
 
@@ -276,6 +280,7 @@ def items
   #   and items in quarantine
   def script_items_by_position
     return [] unless manuscript
+
     hidden_chapters = Chapter.where(hidden: true)
     hidden_sections = Section.where(hidden: true)
                              .or(Section.where(chapter: hidden_chapters))
@@ -296,8 +301,8 @@ def manuscript
 
   def media_with_inheritance_uncached
     Medium.proper.where(teachable: self)
-      .or(Medium.proper.where(teachable: self.lessons))
-      .or(Medium.proper.where(teachable: self.talks))
+          .or(Medium.proper.where(teachable: self.lessons))
+          .or(Medium.proper.where(teachable: self.talks))
   end
 
   def media_with_inheritance_uncached_eagerload_stuff
@@ -307,7 +312,6 @@ def media_with_inheritance_uncached_eagerload_stuff
                     .proper.where(teachable: self.lessons + self.talks))
   end
 
-
   def media_with_inheritance
     Rails.cache.fetch("#{cache_key_with_version}/media_with_inheritance") do
       media_with_inheritance_uncached
@@ -363,32 +367,36 @@ def reste?(user)
     project?('reste', user) || imported_any?('reste')
   end
 
-
   # the next methods put together some information on the lecture (teacher,
   # term, title) in various combinations
 
   def short_title
     return course.short_title unless term
+
     "(#{sort_localized_short}) #{course.short_title} #{term.to_label_short}"
   end
 
   def short_title_release
     return short_title if published?
+
     "#{short_title} (#{I18n.t('access.unpublished')})"
   end
 
   def short_title_brackets
     return course.short_title unless term
+
     "(#{sort_localized_short}) #{course.short_title} (#{term.to_label_short})"
   end
 
   def title_with_teacher
     return title unless teacher.present? && teacher.name.present?
+
     "#{title} (#{teacher.name})"
   end
 
   def title_with_teacher_no_type
     return "#{course.title}, (#{teacher.name})" unless term
+
     "#{course.title}, #{term.to_label} (#{teacher.name})"
   end
 
@@ -396,11 +404,13 @@ def term_teacher_info
     return term_to_label unless teacher.present?
     return term_to_label unless teacher.name.present?
     return "#{course.title}, #{teacher.name}" unless term
+
     "(#{sort_localized_short}) #{term_to_label}, #{teacher.name}"
   end
 
   def term_teacher_published_info
     return term_teacher_info if published?
+
     "#{term_teacher_info} (#{I18n.t('access.unpublished')})"
   end
 
@@ -410,11 +420,13 @@ def title_term_info
 
   def title_term_info_no_type
     return course.title unless term
+
     "#{course.title}, #{term_to_label}"
   end
 
   def title_teacher_info
     return course.title unless teacher.present? && teacher.name.present?
+
     "(#{sort_localized_short}) #{course.title} (#{teacher.name})"
   end
 
@@ -501,12 +513,14 @@ def editors_with_inheritance
 
   def edited_by?(user)
     return true if editors_with_inheritance.include?(user)
+
     false
   end
 
   # returns path for show action of the lecture's course,
   def path(user)
     return unless user.lectures.include?(self)
+
     Rails.application.routes.url_helpers
          .lecture_path(self)
   end
@@ -537,8 +551,8 @@ def lecture_lesson_results(filtered_media)
     lecture_results +
       lesson_results.includes(:teachable)
                     .sort_by do |m|
-                      [order_factor*m.lesson.date.jd,
-                       order_factor*m.lesson.id,
+                      [order_factor * m.lesson.date.jd,
+                       order_factor * m.lesson.id,
                        m.position]
                     end +
       talk_results.includes(:teachable).sort_by do |m|
@@ -549,6 +563,7 @@ def lecture_lesson_results(filtered_media)
   def order_factor
     return -1 unless lecture.term.present?
     return -1 if lecture.term.active
+
     1
   end
 
@@ -580,6 +595,7 @@ def forum
   # by the user
   def unread_forum_topics_count(user)
     return unless forum?
+
     forum_relation = Thredded::Messageboard.where(id: forum_id)
     forum_view =
       Thredded::MessageboardGroupView.grouped(forum_relation,
@@ -609,11 +625,13 @@ def self.select_sorts
 
   def seminar?
     return true if sort.in?(['seminar', 'proseminar', 'oberseminar'])
+
     false
   end
 
   def chapter_name
     return 'chapter' unless seminar?
+
     'talk'
   end
 
@@ -628,7 +646,7 @@ def close_comments!(user)
   end
 
   def open_comments!(user)
-    media_with_inheritance.select { |m| m.commontator_thread.is_closed?}
+    media_with_inheritance.select { |m| m.commontator_thread.is_closed? }
                           .each { |m| m.commontator_thread.reopen }
   end
 
@@ -640,10 +658,11 @@ def <=>(other)
     return 0 if self == other
     return 1 if self.begin_date < other.begin_date
     return 1 if self.term == other.term &&
-                  ActiveSupport::Inflector.transliterate(self.course.title) >
-                    ActiveSupport::Inflector.transliterate(other.course.title)
+                ActiveSupport::Inflector.transliterate(self.course.title) >
+                ActiveSupport::Inflector.transliterate(other.course.title)
     return 1 if self.term == other.term && self.course == other.course &&
-                  self.sort_localized < other.sort_localized
+                self.sort_localized < other.sort_localized
+
     -1
   end
 
@@ -652,10 +671,14 @@ def subscribed_by?(user)
   end
 
   def self.search_by(search_params, page)
-    search_params[:types] = [] if search_params[:all_types] == '1' || search_params[:types].nil?
-    search_params[:term_ids] = [] if search_params[:all_terms] == '1' || search_params[:term_ids].nil?
-    search_params[:teacher_ids] = [] if search_params[:all_teachers] == '1' || search_params[:teacher_ids].nil?
-    search_params[:program_ids] = [] if search_params[:all_programs] == '1' || search_params[:program_ids].nil?
+    search_params[:types] =
+      [] if search_params[:all_types] == '1' || search_params[:types].nil?
+    search_params[:term_ids] =
+      [] if search_params[:all_terms] == '1' || search_params[:term_ids].nil?
+    search_params[:teacher_ids] =
+      [] if search_params[:all_teachers] == '1' || search_params[:teacher_ids].nil?
+    search_params[:program_ids] =
+      [] if search_params[:all_programs] == '1' || search_params[:program_ids].nil?
     search = Sunspot.new_search(Lecture)
     # add lectures without term to current term
     if Term.active.try(:id).to_i.to_s.in?(search_params[:term_ids])
@@ -663,9 +686,12 @@ def self.search_by(search_params, page)
     end
     search.build do
       with(:sort, search_params[:types]) unless search_params[:types].empty?
-      with(:teacher_id, search_params[:teacher_ids]) unless search_params[:teacher_ids].empty?
-      with(:program_ids, search_params[:program_ids]) unless search_params[:program_ids].empty?
-      with(:term_id, search_params[:term_ids]) unless search_params[:term_ids].empty?
+      with(:teacher_id,
+           search_params[:teacher_ids]) unless search_params[:teacher_ids].empty?
+      with(:program_ids,
+           search_params[:program_ids]) unless search_params[:program_ids].empty?
+      with(:term_id,
+           search_params[:term_ids]) unless search_params[:term_ids].empty?
     end
     admin = User.find_by_id(search_params[:user_id])&.admin
     unless admin
@@ -692,11 +718,13 @@ def self.search_by(search_params, page)
 
   def term_to_label
     return term.to_label if term
+
     ''
   end
 
   def term_to_label_short
     return term.to_label_short if term
+
     ''
   end
 
@@ -727,13 +755,13 @@ def previous_assignments
 
   def scheduled_assignments?
     media.where(sort: 'Nuesse').where.not(publisher: nil)
-          .any? { |m| m.publisher.create_assignment }
+         .any? { |m| m.publisher.create_assignment }
   end
 
   def scheduled_assignments
     media.where(sort: 'Nuesse').where.not(publisher: nil)
-          .select { |m| m.publisher.create_assignment }
-          .map { |m| m.publisher.assignment }
+         .select { |m| m.publisher.create_assignment }
+         .map { |m| m.publisher.assignment }
   end
 
   def assignments?
@@ -762,111 +790,118 @@ def importable_toc?
 
   def import_toc!(imported_lecture, import_sections, import_tags)
     return unless imported_lecture
+
     imported_lecture.chapters.each do |c|
       new_chapter = c.dup
       new_chapter.lecture = self
       new_chapter.save
       next unless import_sections
+
       c.sections.each { |s| s.duplicate_in_chapter(new_chapter, import_tags) }
     end
   end
 
   private
 
-  # used for after save callback
-  def remove_teacher_as_editor
-    editors.delete(teacher)
-  end
-
-  # looks in the cache if there are any media associated *with inheritance*
-  # to this lecture and a given project (kaviar, sesam etc.)
-  def project_as_user?(project)
-    Rails.cache.fetch("#{cache_key_with_version}/#{project}") do
-      Medium.where(sort: medium_sort[project],
-                   released: ['all', 'users', 'subscribers'],
-                   teachable: self).exists? ||
-      Medium.where(sort: medium_sort[project],
-                   released: ['all', 'users', 'subscribers'],
-                   teachable: lessons).exists? ||
-      Medium.where(sort: medium_sort[project],
-                   released: ['all', 'users', 'subscribers'],
-                   teachable: talks).exists? ||
-      Medium.where(sort: medium_sort[project],
-                   released: ['all', 'users', 'subscribers'],
-                   teachable: course).exists?
-    end
-  end
-
-  def imported_any?(project)
-    Rails.cache.fetch("#{cache_key_with_version}/imported_#{project}") do
-      imported_media.exists?(sort: medium_sort[project],
-                             released: ['all', 'users'])
-    end
-  end
-
-  def project?(project, user)
-    return project_as_user?(project) unless edited_by?(user) || user.admin
-    course_media = if user.in?(course.editors) || user.admin
-                     Medium.where(sort: medium_sort[project],
-                                  teachable: course).exists?
-                   else
-                      Medium.where(sort: medium_sort[project],
-                                   released: ['all', 'users', 'subscribers'],
-                                   teachable: course).exists?
-                   end
-    lecture_media = Medium.where(sort: medium_sort[project],
-                                 teachable: self).exists?
-    lesson_media = Medium.where(sort: medium_sort[project],
-                                teachable: lessons).exists?
-    talk_media = Medium.where(sort: medium_sort[project],
+    # used for after save callback
+    def remove_teacher_as_editor
+      editors.delete(teacher)
+    end
+
+    # looks in the cache if there are any media associated *with inheritance*
+    # to this lecture and a given project (kaviar, sesam etc.)
+    def project_as_user?(project)
+      Rails.cache.fetch("#{cache_key_with_version}/#{project}") do
+        Medium.where(sort: medium_sort[project],
+                     released: ['all', 'users', 'subscribers'],
+                     teachable: self).exists? ||
+          Medium.where(sort: medium_sort[project],
+                       released: ['all', 'users', 'subscribers'],
+                       teachable: lessons).exists? ||
+          Medium.where(sort: medium_sort[project],
+                       released: ['all', 'users', 'subscribers'],
+                       teachable: talks).exists? ||
+          Medium.where(sort: medium_sort[project],
+                       released: ['all', 'users', 'subscribers'],
+                       teachable: course).exists?
+      end
+    end
+
+    def imported_any?(project)
+      Rails.cache.fetch("#{cache_key_with_version}/imported_#{project}") do
+        imported_media.exists?(sort: medium_sort[project],
+                               released: ['all', 'users'])
+      end
+    end
+
+    def project?(project, user)
+      return project_as_user?(project) unless edited_by?(user) || user.admin
+
+      course_media = if user.in?(course.editors) || user.admin
+        Medium.where(sort: medium_sort[project],
+                     teachable: course).exists?
+      else
+        Medium.where(sort: medium_sort[project],
+                     released: ['all', 'users', 'subscribers'],
+                     teachable: course).exists?
+      end
+      lecture_media = Medium.where(sort: medium_sort[project],
+                                   teachable: self).exists?
+      lesson_media = Medium.where(sort: medium_sort[project],
+                                  teachable: lessons).exists?
+      talk_media = Medium.where(sort: medium_sort[project],
                                 teachable: talks).exists?
-    course_media || lecture_media || lesson_media || talk_media
-  end
+      course_media || lecture_media || lesson_media || talk_media
+    end
 
-  def medium_sort
-    { 'kaviar' => ['Kaviar'], 'sesam' => ['Sesam'], 'kiwi' => ['Kiwi'],
-      'keks' => ['Quiz'], 'nuesse' => ['Nuesse'],
-      'erdbeere' => ['Erdbeere'], 'script' => ['Script'], 'reste' => ['Reste']}
-  end
+    def medium_sort
+      { 'kaviar' => ['Kaviar'], 'sesam' => ['Sesam'], 'kiwi' => ['Kiwi'],
+        'keks' => ['Quiz'], 'nuesse' => ['Nuesse'],
+        'erdbeere' => ['Erdbeere'], 'script' => ['Script'], 'reste' => ['Reste'] }
+    end
 
-  def touch_media
-    media_with_inheritance.update_all(updated_at: Time.now)
-  end
+    def touch_media
+      media_with_inheritance.update_all(updated_at: Time.now)
+    end
 
-  def touch_lessons
-    lessons.update_all(updated_at: Time.now)
-  end
+    def touch_lessons
+      lessons.update_all(updated_at: Time.now)
+    end
 
-  def touch_siblings(lesson)
-    lessons.update_all(updated_at: Time.now)
-    Medium.where(teachable: lessons).update_all(updated_at: Time.now)
-  end
+    def touch_siblings(lesson)
+      lessons.update_all(updated_at: Time.now)
+      Medium.where(teachable: lessons).update_all(updated_at: Time.now)
+    end
 
-  def touch_chapters
-    chapters.update_all(updated_at: Time.now)
-  end
+    def touch_chapters
+      chapters.update_all(updated_at: Time.now)
+    end
 
-  def touch_sections
-    Section.where(chapter: chapters).update_all(updated_at: Time.now)
-  end
+    def touch_sections
+      Section.where(chapter: chapters).update_all(updated_at: Time.now)
+    end
 
-  def destroy_forum
-    return unless forum
-    forum.destroy
-  end
+    def destroy_forum
+      return unless forum
 
-  def term_independent?
-    return false unless course
-    course.term_independent
-  end
+      forum.destroy
+    end
 
-  def absence_of_term
-    return unless term
-    errors.add(:term, :present)
-  end
+    def term_independent?
+      return false unless course
 
-  def only_one_lecture
-    return unless Lecture.where(course: course).any?
-    errors.add(:course, :already_present)
-  end
+      course.term_independent
+    end
+
+    def absence_of_term
+      return unless term
+
+      errors.add(:term, :present)
+    end
+
+    def only_one_lecture
+      return unless Lecture.where(course: course).any?
+
+      errors.add(:course, :already_present)
+    end
 end
diff --git a/app/models/lesson.rb b/app/models/lesson.rb
index 010568033..852e1dfff 100644
--- a/app/models/lesson.rb
+++ b/app/models/lesson.rb
@@ -11,8 +11,8 @@ class Lesson < ApplicationRecord
   # taught in the lesson
   has_many :lesson_section_joins, dependent: :destroy
   has_many :sections, through: :lesson_section_joins,
-           after_remove: :touch_section,
-           after_add: :touch_section
+                      after_remove: :touch_section,
+                      after_add: :touch_section
 
   # being a teachable (course/lecture/lesson), a lesson has associated media
   has_many :media, -> { order(position: :asc) },
@@ -40,6 +40,7 @@ class Lesson < ApplicationRecord
 
   def course
     return unless lecture.present?
+
     lecture.course
   end
 
@@ -100,6 +101,7 @@ def card_header
 
   def card_header_path(user)
     return unless user.lectures.include?(lecture)
+
     lesson_path
   end
 
@@ -133,11 +135,13 @@ def restricted?
 
   def term
     return unless lecture.present?
+
     lecture.term
   end
 
   def previous
     return unless number > 1
+
     lecture.lessons[number - 2]
   end
 
@@ -149,7 +153,7 @@ def published_media
     media.published
   end
 
-   # visible media are published with inheritance and unlocked
+  # visible media are published with inheritance and unlocked
   def visible_media_for_user(user)
     media.select { |m| m.visible_for_user?(user) }
   end
@@ -198,6 +202,7 @@ def visible_items
 
   def content_items
     return visible_items if lecture.content_mode == 'video'
+
     script_items
   end
 
@@ -207,6 +212,7 @@ def content
 
   def singular_medium
     return false if media.count != 1
+
     media.first
   end
 
@@ -214,13 +220,16 @@ def singular_medium
   # (relevant if lecture content mode is manuscript)
   def script_items
     return [] unless lecture.manuscript && start_destination && end_destination
+
     start_item = Item.where(medium: lecture.manuscript,
                             pdf_destination: start_destination)&.first
     end_item = Item.where(medium: lecture.manuscript,
-                            pdf_destination: end_destination)&.first
+                          pdf_destination: end_destination)&.first
     return [] unless start_item && end_item
+
     range = (start_item.position..end_item.position).to_a
     return [] unless range.present?
+
     hidden_chapters = Chapter.where(hidden: true)
     hidden_sections = Section.where(hidden: true)
                              .or(Section.where(chapter: hidden_chapters))
@@ -260,12 +269,14 @@ def self.editable_selection(user)
   def guess_start_destination
     return start_destination if start_destination
     return unless previous
+
     probable_start_destination
   end
 
   def guess_end_destination
     return end_destination if end_destination
     return unless previous
+
     probable_start_destination
   end
 
@@ -273,11 +284,14 @@ def probable_start_destination
     end_item = Item.where(medium: lecture.manuscript,
                           pdf_destination: previous.end_destination)&.first
     return unless end_item
+
     position = end_item.position
     return unless position
+
     successor = lecture.script_items_by_position.where('position > ?', position)
                        .order(:position)&.first&.pdf_destination
     return successor if successor
+
     end_item.pdf_destination
   end
 
@@ -287,37 +301,37 @@ def tags_without_section
 
   private
 
-  # path for show lesson action
-  def lesson_path
-    Rails.application.routes.url_helpers.lesson_path(self)
-  end
+    # path for show lesson action
+    def lesson_path
+      Rails.application.routes.url_helpers.lesson_path(self)
+    end
 
-  # used for after save callback
-  def touch_media
-    lecture.media_with_inheritance.update_all(updated_at: Time.now)
-  end
+    # used for after save callback
+    def touch_media
+      lecture.media_with_inheritance.update_all(updated_at: Time.now)
+    end
 
-  def touch_siblings
-    lecture.lessons.update_all(updated_at: Time.now)
-  end
+    def touch_siblings
+      lecture.lessons.update_all(updated_at: Time.now)
+    end
 
-  def touch_sections
-    sections.update_all(updated_at: Time.now)
-    chapters = sections.map(&:chapter)
-    sections.map(&:chapter).each(&:touch)
-    lecture.touch
-  end
+    def touch_sections
+      sections.update_all(updated_at: Time.now)
+      chapters = sections.map(&:chapter)
+      sections.map(&:chapter).each(&:touch)
+      lecture.touch
+    end
 
-  def touch_self
-    touch
-  end
+    def touch_self
+      touch
+    end
 
-  def touch_tags
-    tags.update_all(updated_at: Time.now)
-  end
+    def touch_tags
+      tags.update_all(updated_at: Time.now)
+    end
 
-  def touch_section(section)
-    section.touch
-    section.chapter.touch
-  end
+    def touch_section(section)
+      section.touch
+      section.chapter.touch
+    end
 end
diff --git a/app/models/link.rb b/app/models/link.rb
index 8511878ee..285eef6c0 100644
--- a/app/models/link.rb
+++ b/app/models/link.rb
@@ -17,27 +17,27 @@ class Link < ApplicationRecord
 
   private
 
-  def self_inverse?
-    medium_id == linked_medium_id
-  end
+    def self_inverse?
+      medium_id == linked_medium_id
+    end
 
-  def create_inverse
-    self.class.create(inverse_link_options)
-  end
+    def create_inverse
+      self.class.create(inverse_link_options)
+    end
 
-  def destroy_inverses
-    inverses.destroy_all
-  end
+    def destroy_inverses
+      inverses.destroy_all
+    end
 
-  def inverse?
-    self.class.exists?(inverse_link_options) || self_inverse?
-  end
+    def inverse?
+      self.class.exists?(inverse_link_options) || self_inverse?
+    end
 
-  def inverses
-    self.class.where(inverse_link_options)
-  end
+    def inverses
+      self.class.where(inverse_link_options)
+    end
 
-  def inverse_link_options
-    { linked_medium_id: medium_id, medium_id: linked_medium_id }
-  end
+    def inverse_link_options
+      { linked_medium_id: medium_id, medium_id: linked_medium_id }
+    end
 end
diff --git a/app/models/mampf_expression.rb b/app/models/mampf_expression.rb
index 4122ab91b..b0c09afc1 100644
--- a/app/models/mampf_expression.rb
+++ b/app/models/mampf_expression.rb
@@ -16,4 +16,4 @@ def self.trivial_instance
   def self.from_hash(content)
     MampfExpression.new(content['0'], content['tex'], content['nerd'])
   end
-end
\ No newline at end of file
+end
diff --git a/app/models/mampf_matrix.rb b/app/models/mampf_matrix.rb
index 4e2a712a1..fbe5c1562 100644
--- a/app/models/mampf_matrix.rb
+++ b/app/models/mampf_matrix.rb
@@ -18,11 +18,12 @@ def self.trivial_instance
              'matrix([0,0],[0,0]')
   end
 
-  def entry(i,j)
+  def entry(i, j)
     if i > @row_count || j > @column_count
       return '0'
     end
-    @coefficients[(i - 1) *  @column_count + (j - 1)]
+
+    @coefficients[(i - 1) * @column_count + (j - 1)]
   end
 
   def self.from_hash(content)
diff --git a/app/models/mampf_set.rb b/app/models/mampf_set.rb
index 2b64143b7..333e8d08a 100644
--- a/app/models/mampf_set.rb
+++ b/app/models/mampf_set.rb
@@ -16,4 +16,4 @@ def self.trivial_instance
   def self.from_hash(content)
     MampfSet.new(content['0'], content['tex'], content['nerd'])
   end
-end
\ No newline at end of file
+end
diff --git a/app/models/mampf_tuple.rb b/app/models/mampf_tuple.rb
index df4213fcd..dd997f92a 100644
--- a/app/models/mampf_tuple.rb
+++ b/app/models/mampf_tuple.rb
@@ -16,4 +16,4 @@ def self.trivial_instance
   def self.from_hash(content)
     MampfTuple.new(content['0'], content['tex'], content['nerd'])
   end
-end
\ No newline at end of file
+end
diff --git a/app/models/manuscript.rb b/app/models/manuscript.rb
index 860477733..f11e245e7 100644
--- a/app/models/manuscript.rb
+++ b/app/models/manuscript.rb
@@ -13,6 +13,7 @@ def initialize(medium)
            medium.manuscript
       return
     end
+
     @medium = medium
     @lecture = medium.teachable.lecture
     @locale = @lecture.locale_with_inheritance || I18n.default_locale
@@ -90,6 +91,7 @@ def manuscript_chapter_contradicts?(chapter)
   # - creates items and tags for new content, depending on the users choices
   def export_to_db!(filter_boxes)
     return unless @contradiction_count.zero?
+
     create_new_chapters!
     @chapters.each do |c|
       create_new_sections!(c)
@@ -126,6 +128,7 @@ def create_new_chapters!
   # create sections in mampf for those manuscript sections not yet in mampf
   def create_new_sections!(chapter)
     return if chapter['mampf_chapter'].nil?
+
     mampf_chapter = chapter['mampf_chapter']
     new_sections_in_chapter(chapter).each do |s|
       sect = Section.new(chapter_id: mampf_chapter.id, title: s.second)
@@ -156,7 +159,8 @@ def create_or_update_chapter_items!
           description: c['description'],
           ref_number: c['label'],
           position: nil,
-          quarantine: nil })
+          quarantine: nil }
+      )
     end
     create_or_update_items!(contents, item_details, item_destinations,
                             item_id_map)
@@ -185,7 +189,8 @@ def create_or_update_section_items!
           description: s['description'],
           ref_number: s['label'],
           position: -1,
-          quarantine: nil })
+          quarantine: nil }
+      )
     end
     create_or_update_items!(contents, item_details, item_destinations,
                             item_id_map)
@@ -217,7 +222,8 @@ def create_or_update_content_items!(filter_boxes)
           ref_number: c['label'],
           position: c['counter'],
           hidden: filter_boxes[c['counter']].third == false,
-          quarantine: nil })
+          quarantine: nil }
+      )
     end
     create_or_update_items!(contents, item_details, item_destinations,
                             item_id_map)
@@ -257,11 +263,13 @@ def update_tags!(filter_boxes)
           next unless tag
           next unless section
           next if section.in?(tag.sections)
+
           tag.sections |= [section]
           tag.courses |= [@lecture.course]
           next
         end
         next unless filter_boxes[c['counter']].second
+
         # if checkbox for tag creation is checked, create the tag,
         # associate it with course and section
         tag = Tag.new(courses: [@lecture.course],
@@ -316,7 +324,7 @@ def add_info_on_item_ids_and_hidden_status
     end
   end
 
-#  private
+  #  private
 
   def get_chapters(bookmarks)
     bookmarks.select { |b| b['sort'] == @chapter_marker }
@@ -340,10 +348,10 @@ def match_mampf_chapters
       c['mampf_chapter'] = mampf_chapter
       c['contradiction'] = if mampf_chapter.nil? ||
                               mampf_chapter.title == c['description']
-                             false
-                           else
-                             :different_title
-                           end
+        false
+      else
+        :different_title
+      end
     end
   end
 
@@ -359,10 +367,10 @@ def match_mampf_sections
       s['mampf_section'] = mampf_section
       s['contradiction'] = if mampf_section.nil? ||
                               mampf_section.title == s['description']
-                             false
-                           else
-                             :different_title
-                           end
+        false
+      else
+        :different_title
+      end
     end
   end
 
@@ -371,12 +379,12 @@ def check_content
     bookmarked_chapter_counters = @chapters.map { |c| c['chapter'] }
     @content.each do |c|
       c['contradiction'] = if !c['chapter'].in?(bookmarked_chapter_counters)
-                             :missing_chapter
-                           elsif !c['section'].in?(bookmarked_section_counters)
-                             :missing_section
-                           else
-                             false
-                           end
+        :missing_chapter
+      elsif !c['section'].in?(bookmarked_section_counters)
+        :missing_section
+      else
+        false
+      end
     end
   end
 
@@ -396,6 +404,7 @@ def determine_contradiction_count
 
   def version_info
     return [] if @version == DefaultSetting::MAMPF_STY_VERSION
+
     [@version.to_s]
   end
 
diff --git a/app/models/medium.rb b/app/models/medium.rb
index 687e24a37..8da3bfc4f 100644
--- a/app/models/medium.rb
+++ b/app/models/medium.rb
@@ -40,12 +40,11 @@ class Medium < ApplicationRecord
   has_many :referrals, dependent: :destroy
   has_many :referenced_items, through: :referrals, source: :item
 
-
   has_many :imports, dependent: :destroy
   has_many :importing_lectures, through: :imports,
-           source: :teachable, source_type: 'Lecture'
+                                source: :teachable, source_type: 'Lecture'
   has_many :importing_courses, through: :imports,
-           source: :teachable, source_type: 'Course'
+                               source: :teachable, source_type: 'Course'
 
   has_many :quiz_certificates, foreign_key: 'quiz_id', dependent: :destroy
 
@@ -120,9 +119,13 @@ class Medium < ApplicationRecord
   # (they may not be globally visible as their lecture may be unpublished)
   scope :published, -> { where.not(released: nil) }
   scope :locally_visible, -> { where(released: ['all', 'users']) }
-  scope :potentially_visible, -> { where(released: ['all', 'users', 'subscribers']) }
+  scope :potentially_visible, -> {
+                                where(released: ['all', 'users', 'subscribers'])
+                              }
   scope :proper, -> { where.not(sort: 'RandomQuiz') }
-  scope :expired, -> { where(sort: 'RandomQuiz').where('created_at < ?', 1.day.ago) }
+  scope :expired, -> {
+                    where(sort: 'RandomQuiz').where('created_at < ?', 1.day.ago)
+                  }
 
   searchable do
     text :description do
@@ -194,7 +197,6 @@ def self.sort_localized_short
       'Reste' => I18n.t('categories.reste.short') }
   end
 
-
   def self.select_sorts
     Medium.sort_localized.except('RandomQuiz').map { |k, v| [v, k] }
   end
@@ -230,6 +232,7 @@ def self.select_question
   def self.search_all(params)
     lecture = Lecture.find_by_id(params[:id])
     return Medium.none if lecture.nil?
+
     media_in_project = Medium.media_in_project(params[:project])
     # media sitting at course level
     course_media_in_project = media_in_project.includes(:tags)
@@ -244,6 +247,7 @@ def self.search_all(params)
   # returns the ARel of all media for the given project
   def self.media_in_project(project)
     return Medium.none unless project.present?
+
     sort = project == 'keks' ? 'Quiz' : project.capitalize
     Medium.where(sort: sort)
   end
@@ -263,6 +267,7 @@ def self.search_sorts(search_params)
     unless search_params[:all_types] == '0'
       return (Medium.sort_enum - ['RandomQuiz'])
     end
+
     search_params[:types] || []
   end
 
@@ -280,9 +285,10 @@ def self.search_by(search_params, page)
     search_params[:types] = [] if search_params[:all_types] == '1'
     search_params[:teachable_ids] = TeachableParser.new(search_params)
                                                    .teachables_as_strings
-    search_params[:editor_ids] = [] if search_params[:all_editors] == '1' || search_params[:all_editors].nil?
+    search_params[:editor_ids] =
+      [] if search_params[:all_editors] == '1' || search_params[:all_editors].nil?
     # add media without term to current term
-    
+
     search_params[:all_terms] = '1' if search_params[:all_terms].blank?
     search_params[:all_teachers] = '1' if search_params[:all_teachers].blank?
     search_params[:term_ids].push('0') if search_params[:term_ids].present?
@@ -296,8 +302,10 @@ def self.search_by(search_params, page)
       without(:sort, Medium.advanced_sorts) unless admin
       with(:editor_ids, search_params[:editor_ids])
       with(:teachable_compact, search_params[:teachable_ids])
-      with(:term_id, search_params[:term_ids]) unless search_params[:all_terms] == '1'
-      with(:teacher_id, search_params[:teacher_ids]) unless search_params[:all_teachers] == '1'
+      with(:term_id,
+           search_params[:term_ids]) unless search_params[:all_terms] == '1'
+      with(:teacher_id,
+           search_params[:teacher_ids]) unless search_params[:all_teachers] == '1'
     end
     if search_params[:purpose] == 'clicker'
       search.build do
@@ -315,7 +323,7 @@ def self.search_by(search_params, page)
       end
     end
     unless search_params[:all_tags] == '1' &&
-             search_params[:tag_operator] == 'or'
+           search_params[:tag_operator] == 'or'
       if search_params[:tag_ids]
         if search_params[:tag_operator] == 'or' || search_params[:all_tags] == '1'
           search.build do
@@ -375,6 +383,7 @@ def self.similar_courses(search_string)
 
   def restricted?
     return false unless teachable
+
     teachable.restricted?
   end
 
@@ -386,12 +395,14 @@ def restricted?
   # where the user temporarily commented out some part of the manuscript)
   def protected_items
     return [] unless sort == 'Script'
+
     pdf_items = Item.where(medium: self).where.not(pdf_destination: nil)
     Referral.where(item: pdf_items).map(&:item).uniq
   end
 
   def vanished_items
     return [] unless sort == 'Script'
+
     Item.where(medium: self)
         .where.not(sort: 'self')
         .where.not(pdf_destination: manuscript_destinations)
@@ -422,6 +433,7 @@ def quarantine
   #   return these)
   def update_pdf_destinations!
     return unless sort == 'Script'
+
     irrelevant_items.delete_all
     result = missing_items_outside_quarantine.pluck(:pdf_destination)
     missing_items_outside_quarantine.update_all(quarantine: true)
@@ -431,6 +443,7 @@ def update_pdf_destinations!
   # is the given user an editor of this medium?
   def edited_by?(user)
     return true if editors.include?(user)
+
     false
   end
 
@@ -443,18 +456,20 @@ def edited_with_inheritance_by?(user)
     return true if teachable&.lecture&.teacher == user
     return true if teachable&.course&.editors&.include?(user)
     return true if teachable&.is_a?(Talk) && user.in?(teachable.speakers)
+
     false
   end
 
   def editors_with_inheritance
     return [] if sort == 'RandomQuiz'
+
     result = (editors&.to_a + teachable.lecture&.editors.to_a +
       [teachable.lecture&.teacher] + teachable.course.editors.to_a).uniq.compact
     return result unless teachable.is_a?(Talk)
+
     (result + teachable.speakers).uniq
   end
 
-
   # creates a .vtt tmp file (and returns it), which contains
   # all data needed by the thyme player to realize the toc
   def toc_to_vtt
@@ -507,11 +522,13 @@ def referrals_by_time
 
   def screenshot_url_with_host
     return screenshot_url(host: host) unless screenshot(:normalized)
+
     return screenshot_url(:normalized, host: host)
   end
 
   def video_url
     return unless video.present?
+
     video.url(host: host)
   end
 
@@ -521,36 +538,43 @@ def video_download_url
 
   def video_filename
     return unless video.present?
+
     video.metadata['filename']
   end
 
   def video_size
     return unless video.present?
+
     video.metadata['size']
   end
 
   def video_resolution
     return unless video.present?
+
     video.metadata['resolution']
   end
 
   def video_duration
     return unless video.present?
+
     video.metadata['duration']
   end
 
   def video_duration_hms_string
     return unless video.present?
+
     TimeStamp.new(total_seconds: video_duration).hms_string
   end
 
   def geogebra_filename
     return unless geogebra.present?
+
     geogebra.metadata['filename']
   end
 
   def geogebra_size
     return unless geogebra.present?
+
     geogebra.metadata['size']
   end
 
@@ -564,11 +588,13 @@ def geogebra_download_url
 
   def geogebra_screenshot_url
     return '' unless geogebra.present?
+
     geogebra_url(:screenshot, host: host)
   end
 
   def manuscript_url_with_host
-    return manuscript_url(host: host) + "/"+manuscript_filename if ENV["REWRITE_ENABLED"]=="1"
+    return manuscript_url(host: host) + "/" + manuscript_filename if ENV["REWRITE_ENABLED"] == "1"
+
     manuscript_url(host: host)
   end
 
@@ -578,53 +604,62 @@ def manuscript_download_url
 
   def manuscript_filename
     return unless manuscript.present?
+
     return manuscript.metadata['filename']
   end
 
   def manuscript_size
     return unless manuscript.present?
+
     return manuscript.metadata['size']
   end
 
   def manuscript_pages
     return unless manuscript.present?
+
     return manuscript.metadata['pages']
   end
 
-
   def manuscript_screenshot_url
     return '' unless manuscript.present?
+
     manuscript_url(:screenshot, host: host)
   end
 
   def manuscript_destinations
     return [] unless manuscript.present? && sort == 'Script'
+
     manuscript.metadata['destinations'] || []
   end
 
   def video_width
     return unless video.present?
+
     video_resolution.split('x')[0].to_i
   end
 
   def video_height
     return unless video.present?
+
     video_resolution.split('x')[1].to_i
   end
 
   def video_aspect_ratio
     return unless video_height != 0 && video_width != 0
+
     video_width.to_f / video_height
   end
 
   def video_scaled_height(new_width)
     return unless video_height != 0 && video_width != 0
+
     (new_width.to_f / video_aspect_ratio).to_i
   end
 
   def caption
     return description if description.present?
     return '' unless sort == 'Kaviar' && teachable_type == 'Lesson'
+
     teachable.section_titles || ''
   end
 
@@ -644,6 +679,7 @@ def card_subheader
 
   def card_tooltip
     return Medium.sort_localized[sort] unless sort == 'Nuesse' && file_last_edited
+
     I18n.t('categories.exercises.singular_updated')
   end
 
@@ -653,6 +689,7 @@ def sort_localized
 
   def subheader_style
     return 'badge badge-secondary' unless sort == 'Nuesse' && file_last_edited
+
     'badge badge-danger'
   end
 
@@ -689,6 +726,7 @@ def visible_for_user?(user)
     return true if edited_with_inheritance_by?(user)
     return false unless published?
     return false if locked?
+
     if teachable_type == 'Course'
       return false if restricted? && !teachable.in?(user.courses)
     end
@@ -700,16 +738,19 @@ def visible_for_user?(user)
 
   def course
     return if teachable.nil?
+
     teachable.course
   end
 
   def lecture
     return if teachable.nil?
+
     teachable.lecture
   end
 
   def lesson
     return if teachable.nil?
+
     teachable.lesson
   end
 
@@ -720,6 +761,7 @@ def irrelevant?
 
   def teachable_select
     return nil unless teachable.present?
+
     teachable_type + '-' + teachable_id.to_s
   end
 
@@ -733,6 +775,7 @@ def siblings
 
   def compact_info_uncached
     return "#{sort_localized}.#{teachable.compact_title}" unless quizzy?
+
     "#{sort_localized}.#{teachable.compact_title}.\##{id}"
   end
 
@@ -749,10 +792,11 @@ def compact_info
   def local_info_uncached
     return description if description.present?
     return I18n.t('admin.medium.local_info.no_title') unless undescribable?
-    if sort == 'Kaviar' &&  teachable_type == 'Lesson'
-        return I18n.t('admin.medium.local_info.to_session',
-                      number: teachable.number,
-                      date: teachable.date_localized)
+
+    if sort == 'Kaviar' && teachable_type == 'Lesson'
+      return I18n.t('admin.medium.local_info.to_session',
+                    number: teachable.number,
+                    date: teachable.date_localized)
 
     elsif sort == 'Script'
       return I18n.t('categories.script.singular')
@@ -768,6 +812,7 @@ def local_info
 
   def local_info_for_admins_uncached
     return local_info unless quizzy?
+
     "\##{id}.#{local_info}"
   end
 
@@ -784,6 +829,7 @@ def details_uncached
     unless undescribable?
       return "#{I18n.t('admin.medium.local_info.no_title')}.ID#{id}"
     end
+
     ''
   end
 
@@ -795,6 +841,7 @@ def details
 
   def title_uncached
     return compact_info if details.blank?
+
     compact_info + '.' + details
   end
 
@@ -825,14 +872,14 @@ def scoped_teachable_title
 
   # returns info made from sort and description
   def local_title_for_viewers_uncached
-    return"#{sort_localized}, #{description}" if description.present?
+    return "#{sort_localized}, #{description}" if description.present?
     if sort == 'Kaviar' && teachable.class.to_s == 'Lesson'
       return "#{I18n.t('categories.kaviar.singular')}, #{teachable.local_title_for_viewers}"
     end
+
     "#{sort_localized}, #{I18n.t('admin.medium.local_info.no_title')}"
   end
 
-
   # returns info made from sort and description
   def local_title_for_viewers
     Rails.cache.fetch("#{cache_key_with_version}/local_title_for_viewers") do
@@ -868,6 +915,7 @@ def items_with_references
 
   def proper?
     return true unless sort == 'RandomQuiz'
+
     false
   end
 
@@ -883,14 +931,14 @@ def sanitize_type!
 
   def select_sorts
     result = if new_record?
-               Medium.sort_localized.except('RandomQuiz')
-             elsif sort.in?(['Kaviar', 'Sesam', 'Erdbeere', 'Kiwi', 'Nuesse',
-                            'Reste'])
-               Medium.sort_localized.except('RandomQuiz', 'Script', 'Quiz',
-                                            'Question', 'Remark')
-             else
-               Medium.sort_localized.slice(sort)
-             end
+      Medium.sort_localized.except('RandomQuiz')
+    elsif sort.in?(['Kaviar', 'Sesam', 'Erdbeere', 'Kiwi', 'Nuesse',
+                    'Reste'])
+      Medium.sort_localized.except('RandomQuiz', 'Script', 'Quiz',
+                                   'Question', 'Remark')
+    else
+      Medium.sort_localized.slice(sort)
+    end
     if teachable_type == 'Talk'
       result.except!('RandomQuiz', 'Question', 'Remark', 'Erdbeere', 'Script')
     end
@@ -924,12 +972,14 @@ def linked_media_ids_cached
 
   def toc_items
     return [] unless sort == 'Script'
+
     items.where(sort: ['chapter', 'section'])
          .natural_sort_by { |x| [x.page, x.ref_number] }
   end
 
   def tags_outside_lesson
     return Tag.none unless teachable_type == 'Lesson'
+
     tags.where.not(id: teachable.tag_ids)
   end
 
@@ -946,16 +996,19 @@ def script_items_importable?
     return unless teachable_type == 'Lesson'
     return unless teachable.lecture.content_mode == 'manuscript'
     return unless teachable.script_items.any?
+
     true
   end
 
   def import_script_items!
     return unless teachable_type == 'Lesson'
     return unless teachable.lecture.content_mode == 'manuscript'
+
     items = teachable.script_items
     return unless items.any?
+
     items.each_with_index.each do |i, j|
-      Item.create(start_time: TimeStamp.new(h: 0, m:0, s: 0, ms: j),
+      Item.create(start_time: TimeStamp.new(h: 0, m: 0, s: 0, ms: j),
                   sort: i.sort, description: i.description,
                   medium: self, section: i.section,
                   ref_number: i.ref_number,
@@ -972,6 +1025,7 @@ def scoped_teachable
   def publish!
     return if published?
     return unless publisher
+
     success = publisher.publish!
     update(publisher: nil) if success
   end
@@ -979,22 +1033,26 @@ def publish!
   def release_date_set?
     return false unless publisher
     return false unless publisher.release_date
+
     true
   end
 
   def planned_release_date
     return unless publisher
+
     publisher.release_date
   end
 
   def planned_comment_lock?
     return publisher.lock_comments if publisher
+
     !!teachable.media_scope.try(:comments_disabled)
   end
 
   def becomes_quizzable
     return unless type.in?(['Question', 'Remark'])
     return becomes(Question) if type == 'Question'
+
     becomes(Remark)
   end
 
@@ -1038,8 +1096,8 @@ def supervising_teacher_id
   end
 
   def subscribed_users
-
-    return teachable.user_ids if ['Lecture', 'Course'].include? teachable.class.to_s
+    return teachable.user_ids if ['Lecture',
+                                  'Course'].include? teachable.class.to_s
     return unless teachable.class.to_s == 'Lesson'
 
     Lecture.find_by(id: teachable.lecture_id).user_ids
@@ -1047,159 +1105,175 @@ def subscribed_users
 
   private
 
-  # media of type kaviar associated to a lesson and script do not require
-  # a description
-  def undescribable?
-    (sort == 'Kaviar' && teachable.class.to_s == 'Lesson') ||
-      sort == 'Script'
-  end
+    # media of type kaviar associated to a lesson and script do not require
+    # a description
+    def undescribable?
+      (sort == 'Kaviar' && teachable.class.to_s == 'Lesson') ||
+        sort == 'Script'
+    end
 
-  def quizzy?
-    sort.in?(['Quiz', 'Question', 'Remark'])
-  end
+    def quizzy?
+      sort.in?(['Quiz', 'Question', 'Remark'])
+    end
 
-  def title_uncached
-    return compact_info if details.blank?
-    compact_info + '.' + details
-  end
+    def title_uncached
+      return compact_info if details.blank?
 
-  def local_title_for_viewers_uncached
-    return"#{sort_localized}, #{description}" if description.present?
-    if sort == 'Kaviar' && teachable.class.to_s == 'Lesson'
-      return "#{I18n.t('categories.kaviar.singular')}, #{teachable.local_title_for_viewers}"
+      compact_info + '.' + details
     end
-    "#{sort_localized}, #{I18n.t('admin.medium.local_info.no_title')}"
-  end
 
+    def local_title_for_viewers_uncached
+      return "#{sort_localized}, #{description}" if description.present?
+      if sort == 'Kaviar' && teachable.class.to_s == 'Lesson'
+        return "#{I18n.t('categories.kaviar.singular')}, #{teachable.local_title_for_viewers}"
+      end
 
-  def touch_teachable
-    return if teachable.nil?
-    if teachable.course.present? && teachable.course.persisted?
-      teachable.course.touch
+      "#{sort_localized}, #{I18n.t('admin.medium.local_info.no_title')}"
     end
-    optional_touches
-  end
 
-  def reset_released_status
-    return if teachable.nil? || teachable.published?
-    self.released = nil
-  end
+    def touch_teachable
+      return if teachable.nil?
 
-  def optional_touches
-    if teachable.lecture.present? && teachable.lecture.persisted?
-      teachable.lecture.touch
+      if teachable.course.present? && teachable.course.persisted?
+        teachable.course.touch
+      end
+      optional_touches
     end
-    if teachable.lesson.present? && teachable.lesson.persisted?
-      teachable.lesson.touch
+
+    def reset_released_status
+      return if teachable.nil? || teachable.published?
+
+      self.released = nil
     end
-    return unless teachable.talk.present? && teachable.talk.persisted?
-    teachable.talk.touch
-  end
 
-  def vtt_start
-    "WEBVTT\n\n"
-  end
+    def optional_touches
+      if teachable.lecture.present? && teachable.lecture.persisted?
+        teachable.lecture.touch
+      end
+      if teachable.lesson.present? && teachable.lesson.persisted?
+        teachable.lesson.touch
+      end
+      return unless teachable.talk.present? && teachable.talk.persisted?
 
-  def belongs_to_course?(lecture)
-    teachable_type == 'Course' && teachable == lecture.course
-  end
+      teachable.talk.touch
+    end
 
-  def belongs_to_lecture?(lecture)
-    teachable_type == 'Lecture' && teachable == lecture
-  end
+    def vtt_start
+      "WEBVTT\n\n"
+    end
 
-  def belongs_to_lesson?(lecture)
-    teachable_type == 'Lesson' && teachable.lecture == lecture
-  end
+    def belongs_to_course?(lecture)
+      teachable_type == 'Course' && teachable == lecture.course
+    end
 
-  def create_self_item
-    return if sort.in?(['Question', 'Remark', 'RandomQuiz'])
-    Item.create(sort: 'self', medium: self)
-  end
+    def belongs_to_lecture?(lecture)
+      teachable_type == 'Lecture' && teachable == lecture
+    end
 
-  def local_items
-    return teachable.items - items if teachable_type == 'Course'
-    teachable.lecture.items - items
-  end
+    def belongs_to_lesson?(lecture)
+      teachable_type == 'Lesson' && teachable.lecture == lecture
+    end
+
+    def create_self_item
+      return if sort.in?(['Question', 'Remark', 'RandomQuiz'])
 
-  def at_most_one_manuscript
-    return true unless teachable_type == 'Lecture'
-    return true unless sort == 'Script'
-    if (Medium.where(sort: 'Script',
-                     teachable: teachable).to_a - [self]).size.positive?
-      errors.add(:sort, :lecture_manuscript_exists)
-      return false
+      Item.create(sort: 'self', medium: self)
     end
-    true
-  end
 
-  def script_only_for_lectures
-    return true if teachable_type == 'Lecture'
-    return true unless sort == 'Script'
-    errors.add(:sort, :lecture_only)
-    false
-  end
+    def local_items
+      return teachable.items - items if teachable_type == 'Course'
 
-  def no_video_for_script
-    return true unless sort == 'Script'
-    return true unless video.present?
-    errors.add(:sort, :no_video)
-    false
-  end
+      teachable.lecture.items - items
+    end
+
+    def at_most_one_manuscript
+      return true unless teachable_type == 'Lecture'
+      return true unless sort == 'Script'
+
+      if (Medium.where(sort: 'Script',
+                       teachable: teachable).to_a - [self]).size.positive?
+        errors.add(:sort, :lecture_manuscript_exists)
+        return false
+      end
+      true
+    end
+
+    def script_only_for_lectures
+      return true if teachable_type == 'Lecture'
+      return true unless sort == 'Script'
 
-  def no_changing_sort_to_or_from_script
-    if sort_was == 'Script' && sort != 'Script'
-      errors.add(:sort, :no_conversion_from_script)
-      return false
+      errors.add(:sort, :lecture_only)
+      false
     end
-    if persisted? && sort_was != 'Script' && sort == 'Script'
-      errors.add(:sort, :no_conversion_to_script)
-      return false
+
+    def no_video_for_script
+      return true unless sort == 'Script'
+      return true unless video.present?
+
+      errors.add(:sort, :no_video)
+      false
     end
-    true
-  end
 
-  def no_tags_for_scripts
-    return true unless sort == 'Script' && tags.any?
-    errors.add(:tags, :no_tags_allowed)
-    false
-  end
+    def no_changing_sort_to_or_from_script
+      if sort_was == 'Script' && sort != 'Script'
+        errors.add(:sort, :no_conversion_from_script)
+        return false
+      end
+      if persisted? && sort_was != 'Script' && sort == 'Script'
+        errors.add(:sort, :no_conversion_to_script)
+        return false
+      end
+      true
+    end
 
-  def delete_vertices
-    return unless type.in?(['Question', 'Remark'])
-    if type == 'Question'
-      becomes(Question).delete_vertices
-      return
+    def no_tags_for_scripts
+      return true unless sort == 'Script' && tags.any?
+
+      errors.add(:tags, :no_tags_allowed)
+      false
     end
-    becomes(Remark).delete_vertices
-  end
 
-  def delete_answers
-    return unless type == 'Question'
-    becomes(Question).answers.delete_all
-  end
+    def delete_vertices
+      return unless type.in?(['Question', 'Remark'])
 
-  def text_join
-    return unless type.in?(['Question', 'Remark'])
-    return text if type == 'Remark'
-    "#{text} #{becomes(Question).answers&.map(&:text_join)&.join(' ')}"
-  end
+      if type == 'Question'
+        becomes(Question).delete_vertices
+        return
+      end
+      becomes(Remark).delete_vertices
+    end
 
-  def release_state
-    return released unless released.nil?
-    'unpublished'
-  end
+    def delete_answers
+      return unless type == 'Question'
 
-  def clickerizable?
-    return false unless type == 'Question'
-    question = becomes(Question)
-    return false unless question.answers.count.in?((2..6))
-    question.answers.pluck(:value).count(true) == 1
-  end
+      becomes(Question).answers.delete_all
+    end
 
-  def answers_count
-    return -1 unless type == 'Question'
-    becomes(Question).answers.count
-  end
-  
+    def text_join
+      return unless type.in?(['Question', 'Remark'])
+      return text if type == 'Remark'
+
+      "#{text} #{becomes(Question).answers&.map(&:text_join)&.join(' ')}"
+    end
+
+    def release_state
+      return released unless released.nil?
+
+      'unpublished'
+    end
+
+    def clickerizable?
+      return false unless type == 'Question'
+
+      question = becomes(Question)
+      return false unless question.answers.count.in?((2..6))
+
+      question.answers.pluck(:value).count(true) == 1
+    end
+
+    def answers_count
+      return -1 unless type == 'Question'
+
+      becomes(Question).answers.count
+    end
 end
diff --git a/app/models/medium_publisher.rb b/app/models/medium_publisher.rb
index b1d2ffb5a..1d5923632 100644
--- a/app/models/medium_publisher.rb
+++ b/app/models/medium_publisher.rb
@@ -91,6 +91,7 @@ def publish!
 
   def assignment
     return unless @create_assignment
+
     Assignment.new(lecture: medium.teachable,
                    medium_id: @medium_id,
                    title: @assignment_title,
diff --git a/app/models/notification.rb b/app/models/notification.rb
index e155942c6..278066c89 100644
--- a/app/models/notification.rb
+++ b/app/models/notification.rb
@@ -9,12 +9,12 @@ class Notification < ApplicationRecord
 
   paginates_per 12
 
-# retrieve notifiable defined by notifiable_type and notifiable_id
-#  def notifiable
-#    return unless notifiable_type.in?(Notification.allowed_notifiable_types) &&
-#                  notifiable_id.present?
-#    notifiable_type.constantize.find_by_id(notifiable_id)
-#  end
+  # retrieve notifiable defined by notifiable_type and notifiable_id
+  #  def notifiable
+  #    return unless notifiable_type.in?(Notification.allowed_notifiable_types) &&
+  #                  notifiable_id.present?
+  #    notifiable_type.constantize.find_by_id(notifiable_id)
+  #  end
 
   # returns the lecture associated to a notification of type announcement,
   # and teachable for a notification of type medium, nil otherwise
@@ -22,6 +22,7 @@ def teachable
     return unless notifiable.present?
     return if notifiable_type.in?(['Lecture', 'Course'])
     return notifiable.lecture if notifiable_type == 'Announcement'
+
     # notifiable will be a medium, so return its teachable
     notifiable.teachable
   end
@@ -34,13 +35,16 @@ def teachable
   def path(user)
     return unless notifiable.present?
     return edit_profile_path if notifiable_type.in?(['Course', 'Lecture'])
+
     if notifiable_type == 'Announcement'
       return notifiable.lecture.path(user) if notifiable.lecture.present?
+
       return news_path
     end
     if notifiable_type == 'Medium' && notifiable.sort == 'Quiz'
       return medium_path(notifiable)
     end
+
     polymorphic_url(notifiable, only_path: true)
   end
 
@@ -52,21 +56,25 @@ def self.allowed_notifiable_types
 
   def medium?
     return unless notifiable.present?
+
     notifiable_type == 'Medium'
   end
 
   def course?
     return unless notifiable.present?
+
     notifiable.class.to_s == 'Course'
   end
 
   def lecture?
     return unless notifiable.present?
+
     notifiable.class.to_s == 'Lecture'
   end
 
   def announcement?
     return unless notifiable.present?
+
     notifiable.class.to_s == 'Announcement'
   end
 
diff --git a/app/models/notion.rb b/app/models/notion.rb
index 78df58c93..de98a93d9 100644
--- a/app/models/notion.rb
+++ b/app/models/notion.rb
@@ -11,6 +11,7 @@ class Notion < ApplicationRecord
 
   def presence_of_tag
     return if tag || aliased_tag
+
     errors.add(:tag, :no_tag)
   end
 
@@ -26,9 +27,9 @@ def touch_tag_relations
 
   private
 
-  def clear_tag_cache
-    I18n.available_locales.each do |l|
-      Rails.cache.delete("tag_select_by_title_#{l}")
+    def clear_tag_cache
+      I18n.available_locales.each do |l|
+        Rails.cache.delete("tag_select_by_title_#{l}")
+      end
     end
-  end
 end
diff --git a/app/models/probe.rb b/app/models/probe.rb
index 6ac6921ec..59b892754 100644
--- a/app/models/probe.rb
+++ b/app/models/probe.rb
@@ -1,5 +1,7 @@
 class Probe < InteractionsRecord
-  scope :created_between, lambda {|start_date, end_date| where(created_at: start_date.beginning_of_day..end_date.end_of_day)}
+  scope :created_between, lambda { |start_date, end_date|
+                            where(created_at: start_date.beginning_of_day..end_date.end_of_day)
+                          }
   require 'csv'
 
   def self.finished_quizzes(quiz)
@@ -35,10 +37,10 @@ def self.local_success_in_quiz(quiz)
       rel_incorrect = total.zero? ? nil : 100 - rel_correct
       results[q] = { correct: probes.where(question_id: q,
                                            correct: true).count,
-                    incorrect: probes.where(question_id: q,
-                                            correct: false).count,
-                    rel_correct: rel_correct,
-                    rel_incorrect: rel_incorrect }
+                     incorrect: probes.where(question_id: q,
+                                             correct: false).count,
+                     rel_correct: rel_correct,
+                     rel_incorrect: rel_incorrect }
     end
     results
   end
@@ -51,9 +53,8 @@ def self.to_csv
       csv << attributes
 
       all.each do |probe|
-        csv << attributes.map{ |attr| probe.send(attr) }
+        csv << attributes.map { |attr| probe.send(attr) }
       end
     end
   end
-
 end
diff --git a/app/models/program.rb b/app/models/program.rb
index 9a2ee1312..1815a27a6 100644
--- a/app/models/program.rb
+++ b/app/models/program.rb
@@ -1,22 +1,22 @@
 class Program < ApplicationRecord
-	belongs_to :subject
-	has_many :divisions, dependent: :destroy
+  belongs_to :subject
+  has_many :divisions, dependent: :destroy
 
-	translates :name
-	globalize_accessors locales: I18n.available_locales,
-											attributes: translated_attribute_names
+  translates :name
+  globalize_accessors locales: I18n.available_locales,
+                      attributes: translated_attribute_names
 
-	def name_with_subject
-		"#{subject.name}: #{name}"
-	end
+  def name_with_subject
+    "#{subject.name}: #{name}"
+  end
 
-	def courses
-		divisions.map(&:courses).flatten
-	end
+  def courses
+    divisions.map(&:courses).flatten
+  end
 
   # array of all programs together with their ids for use in options_for_select
   def self.select_programs
     Program.includes(:subject).all.sort_by(&:name_with_subject)
-    			 .map { |p| [p.name_with_subject, p.id] }
+           .map { |p| [p.name_with_subject, p.id] }
   end
 end
diff --git a/app/models/question.rb b/app/models/question.rb
index 8dd7c80a9..8d3eb7535 100644
--- a/app/models/question.rb
+++ b/app/models/question.rb
@@ -57,6 +57,7 @@ def self.create_prefilled(label, teachable, editors)
                             question_sort: 'mc',
                             solution: solution)
     return question if question.invalid?
+
     Answer.create(question: question,
                   text: '0',
                   value: true)
@@ -98,6 +99,7 @@ def parsed_text_with_params
 
   def text_with_sample_params(parameters)
     return text unless parameters.present?
+
     result = text
     parameters.keys.each do |p|
       result.gsub!(/\\para{#{Regexp.escape(p)},(.*?)}/, parameters[p].to_s)
@@ -121,14 +123,14 @@ def self.parameters_from_text(text)
 
   private
 
-  def prelim_answer_table
-    table = []
-    size = answer_ids.count
-    (0..2**size - 1).each do |i|
-      hash = {}
-      i.to_bool_a(size).each_with_index.map { |x, j| hash[answer_ids[j]] = x }
-      table.push(hash)
+    def prelim_answer_table
+      table = []
+      size = answer_ids.count
+      (0..2**size - 1).each do |i|
+        hash = {}
+        i.to_bool_a(size).each_with_index.map { |x, j| hash[answer_ids[j]] = x }
+        table.push(hash)
+      end
+      table
     end
-    table
-  end
 end
diff --git a/app/models/quiz.rb b/app/models/quiz.rb
index 5824383f2..bd7871991 100644
--- a/app/models/quiz.rb
+++ b/app/models/quiz.rb
@@ -17,11 +17,13 @@ def label
 
   def publish_vertices!(user, release_state)
     return unless vertices
+
     vertices.keys.each do |v|
       quizzable = quizzable(v)
       next if quizzable.published?
       next if !quizzable.teachable.published?
       next unless user.in?(quizzable.editors_with_inheritance) || user.admin
+
       quizzable.update(released: release_state, released_at: Time.now)
     end
   end
@@ -40,6 +42,7 @@ def quizzables_visible_for_user?(user)
 
   def next_vertex(progress, input = {})
     return default_table[progress] if vertices[progress][:type] == 'Remark'
+
     target_vertex(progress, input)
   end
 
@@ -50,32 +53,38 @@ def replace_reference!(old_quizzable, new_quizzable, answer_map = {})
 
   def vertices
     return if quiz_graph.nil?
+
     quiz_graph.vertices
   end
 
   def edges
     return if quiz_graph.nil?
+
     quiz_graph.edges
   end
 
   def root
     return if quiz_graph.nil?
+
     quiz_graph.root
   end
 
   def default_table
     return if quiz_graph.nil?
+
     quiz_graph.default_table
   end
 
   def question_ids
     return [] unless quiz_graph && quiz_graph.vertices.present?
+
     quiz_graph.vertices.select { |_k, v| v[:type] == 'Question' }
               .values.map { |v| v[:id] }.uniq
   end
 
   def remark_ids
     return [] unless quiz_graph && quiz_graph.vertices.present?
+
     quiz_graph.vertices.select { |_k, v| v[:type] == 'Remark' }.values
               .map { |v| v[:id] }.uniq
   end
@@ -98,6 +107,7 @@ def quizzable(vertex_id)
   def preselected_branch(vertex_id, crosses, fallback)
     successor = next_vertex(vertex_id, crosses)
     return successor unless successor == default_table[vertex_id] && fallback
+
     0
   end
 
@@ -113,6 +123,7 @@ def questions
 
   def questions_count
     return 0 unless quiz_graph
+
     quiz_graph.questions_count
   end
 
@@ -124,8 +135,8 @@ def find_errors
 
   private
 
-  def target_vertex(progress, input)
-    edges.select { |e, t| e[0] == progress && t.include?(input) }&.keys
-        &.first&.second || default_table[progress]
-  end
+    def target_vertex(progress, input)
+      edges.select { |e, t| e[0] == progress && t.include?(input) }&.keys
+          &.first&.second || default_table[progress]
+    end
 end
diff --git a/app/models/quiz_certificate.rb b/app/models/quiz_certificate.rb
index 2df1ce34e..d08069209 100644
--- a/app/models/quiz_certificate.rb
+++ b/app/models/quiz_certificate.rb
@@ -13,7 +13,7 @@ def self.generate_code
 
   private
 
-  def set_code
-    self.code = QuizCertificate.generate_code
-  end
+    def set_code
+      self.code = QuizCertificate.generate_code
+    end
 end
diff --git a/app/models/quiz_graph.rb b/app/models/quiz_graph.rb
index 6711d0a6b..4688aa013 100644
--- a/app/models/quiz_graph.rb
+++ b/app/models/quiz_graph.rb
@@ -18,6 +18,7 @@ def self.dump(quiz_graph)
 
   def update_vertex(vertex_id, branching, hide)
     return if @vertices[vertex_id][:type] == 'Remark'
+
     remove_edges_from!(vertex_id)
     update_edges_for_question!(vertex_id, branching)
     update_hide_solutions!(vertex_id, hide)
@@ -27,6 +28,7 @@ def update_vertex(vertex_id, branching, hide)
   def create_vertex(quizzable)
     return self if quizzable.blank?
     return self if quizzable.invalid?
+
     id = new_vertex_id
     @vertices[id] = { type: quizzable.class.to_s, id: quizzable.id }
     @default_table[id] = 0
@@ -50,8 +52,9 @@ def delete_edge!(source, target)
     if @default_table[source] == target
       @default_table[source] = 0
     end
-    answers = @edges[[source,target]]
+    answers = @edges[[source, target]]
     return unless answers
+
     @edges.delete([source, target])
     affected_hide_solution = @hide_solution.select do |h|
       h.first == source && h.second.in?(answers)
@@ -68,9 +71,11 @@ def delete_edge!(source, target)
 
   def replace_reference!(old_quizzable, new_quizzable, answer_map = {})
     return self unless old_quizzable.class == new_quizzable.class
+
     affected_vertices = referencing_vertices(old_quizzable)
     affected_vertices.each { |v| @vertices[v][:id] = new_quizzable.id }
     return self unless new_quizzable.class.to_s == 'Question'
+
     affected_vertices.each do |v|
       bend_edges_rereferencing!(edges_from(v), answer_map)
       bend_hide_solution_rereferencing!(v, answer_map)
@@ -86,8 +91,11 @@ def reset_vertex_answers_change(id)
 
   def find_errors
     return [I18n.t('admin.quiz.no_vertices')] unless @vertices.present?
+
     branch_undef = @default_table.values.include?(0)
-    no_end = default_table.values.exclude?(-1) && @edges.select { |e| e[1] == -1 }.blank?
+    no_end = default_table.values.exclude?(-1) && @edges.select { |e|
+      e[1] == -1
+    }.blank?
     no_root = @root.blank? || @root.zero?
     messages = []
     messages.push(I18n.t('admin.quiz.undefined_targets')) if branch_undef
@@ -102,6 +110,7 @@ def warnings
 
   def quizzable(id)
     return unless id.in?(@vertices.keys)
+
     @vertices[id][:type].constantize.find_by_id(@vertices[id][:id])
   end
 
@@ -203,6 +212,7 @@ def referencing_vertices(quizzable)
 
   def new_vertex_id
     return 1 unless @vertices.present?
+
     @vertices.keys.max + 1
   end
 
@@ -214,6 +224,7 @@ def border_color_for_cytoscape(id)
     quizzable = quizzable(id)
     return 'orange' unless quizzable.visible?
     return 'chocolate' if quizzable.restricted?
+
     '#222'
   end
 
@@ -234,7 +245,7 @@ def self.build_from_questions(question_ids)
     edges = {}
     default_table = {}
     size = question_ids.size
-    question_ids.each_with_index do |q,i|
+    question_ids.each_with_index do |q, i|
       j = i + 1
       k =   j < size ? j + 1 : -1
       question = Question.find_by_id(q)
@@ -253,7 +264,7 @@ def to_cytoscape
                         background: 'yellowgreen',
                         borderwidth: '0',
                         bordercolor: 'grey',
-                        shape: 'diamond' } )
+                        shape: 'diamond' })
     # add vertices
     @vertices.keys.each do |v|
       result.push(data: cytoscape_vertex(v))
@@ -264,13 +275,13 @@ def to_cytoscape
                         background: 'yellowgreen',
                         borderwidth: '0',
                         bordercolor: '#f4a460',
-                        shape: 'diamond' } )
+                        shape: 'diamond' })
     # add edges
     if @root.in?(@vertices.keys)
       result.push(data: { id: "-2-#{@root}",
                           source: -2,
                           target: @root,
-                          color: '#aaa'} )
+                          color: '#aaa' })
     end
     @vertices.keys.each do |v|
       edges_from_plus_default(v).each do |e|
@@ -306,11 +317,12 @@ def cytoscape_edge(edge)
   end
 
   def questions_count
-    @vertices.values.select { |v| v[:type] == 'Question'}.count
+    @vertices.values.select { |v| v[:type] == 'Question' }.count
   end
 
   def default?(edge)
     return false unless @default_table[edge.first]
+
     @default_table[edge.first] == edge.second
   end
-end
\ No newline at end of file
+end
diff --git a/app/models/quiz_round.rb b/app/models/quiz_round.rb
index fc9b1322f..17ec833f6 100644
--- a/app/models/quiz_round.rb
+++ b/app/models/quiz_round.rb
@@ -52,6 +52,7 @@ def round_id
   def background
     return 'bg-grey-lighten-4' if @hide_solution
     return 'bg-correct' if @correct
+
     'bg-incorrect'
   end
 
@@ -61,75 +62,81 @@ def badge
 
   def statement
     return I18n.t('admin.quiz.correct_result') if @correct
+
     I18n.t('admin.quiz.incorrect_result')
   end
 
   def answers
     return [] unless @answer_shuffle
+
     @answer_shuffle.map { |a| Answer.find_by_id(a) }
   end
 
   def answers_old
     return [] unless @answer_shuffle_old
+
     @answer_shuffle_old.map { |a| Answer.find_by_id(a) }
   end
 
   private
 
-  def progress_counter(params)
-    if params[:quiz].present?
-      @counter = params[:quiz][:counter].to_i
-      @progress = params[:quiz][:progress].to_i
-      @session_id = params[:quiz][:session_id]
+    def progress_counter(params)
+      if params[:quiz].present?
+        @counter = params[:quiz][:counter].to_i
+        @progress = params[:quiz][:progress].to_i
+        @session_id = params[:quiz][:session_id]
+      end
+      @progress ||= @quiz.root
+      @counter ||= 0
+      @session_id ||= SecureRandom.uuid.first(13).remove('-')
+      @progress_old = @progress
+      @counter_old = @counter
+      @round_id_old = round_id
     end
-    @progress ||= @quiz.root
-    @counter ||= 0
-    @session_id ||= SecureRandom.uuid.first(13).remove('-')
-    @progress_old = @progress
-    @counter_old = @counter
-    @round_id_old = round_id
-  end
 
-  def question_details(params)
-    @is_question = true
-    @question_id = @vertex[:id]
-    @answer_scheme = Question.find(@question_id).answer_scheme
-    if params[:quiz].present? && params[:quiz][:answer_shuffle].present?
-      @answer_shuffle = JSON.parse(params[:quiz][:answer_shuffle]).map(&:to_i)
-    else
-      @answer_shuffle = Question.find(@question_id).answers.map(&:id).shuffle
+    def question_details(params)
+      @is_question = true
+      @question_id = @vertex[:id]
+      @answer_scheme = Question.find(@question_id).answer_scheme
+      if params[:quiz].present? && params[:quiz][:answer_shuffle].present?
+        @answer_shuffle = JSON.parse(params[:quiz][:answer_shuffle]).map(&:to_i)
+      else
+        @answer_shuffle = Question.find(@question_id).answers.map(&:id).shuffle
+      end
     end
-  end
 
-  def remark_details(params)
-    @is_remark = true
-    @remark_id = @vertex[:id]
-  end
+    def remark_details(params)
+      @is_remark = true
+      @remark_id = @vertex[:id]
+    end
 
-  def update_answer_shuffle
-    @answer_shuffle = Question.find_by_id(@vertex[:id])&.answers&.map(&:id)
-                             &.shuffle
-  end
+    def update_answer_shuffle
+      @answer_shuffle = Question.find_by_id(@vertex[:id])&.answers&.map(&:id)
+                               &.shuffle
+    end
 
-  def create_question_probe
-    return unless @save_probe
-    quiz_id = @quiz.id unless @quiz.sort == 'RandomQuiz'
-    input = @solution_input || @input.to_s if @study_participant
-    ProbeSaver.perform_async(quiz_id, @question_id, nil, @correct, @progress,
-                             @session_id, @study_participant, input)
-  end
+    def create_question_probe
+      return unless @save_probe
 
-  def create_remark_probe
-    return unless @save_probe
-    quiz_id = @quiz.id unless @quiz.sort == 'RandomQuiz'
-    ProbeSaver.perform_async(quiz_id, nil, @remark_id, nil, @progress,
-                             @session_id, @study_participant, @input_text)
-  end
+      quiz_id = @quiz.id unless @quiz.sort == 'RandomQuiz'
+      input = @solution_input || @input.to_s if @study_participant
+      ProbeSaver.perform_async(quiz_id, @question_id, nil, @correct, @progress,
+                               @session_id, @study_participant, input)
+    end
 
-  def create_certificate_final_probe
-    return unless @save_probe
-    @certificate = QuizCertificate.create(quiz: @quiz)
-    ProbeSaver.perform_async(@quiz.id, nil, nil, nil, -1, @session_id,
-                             @study_participant, nil)
-  end
+    def create_remark_probe
+      return unless @save_probe
+
+      quiz_id = @quiz.id unless @quiz.sort == 'RandomQuiz'
+      ProbeSaver.perform_async(quiz_id, nil, @remark_id, nil, @progress,
+                               @session_id, @study_participant, @input_text)
+    end
+
+    def create_certificate_final_probe
+      return unless @save_probe
+
+      @certificate = QuizCertificate.create(quiz: @quiz)
+      ProbeSaver.perform_async(@quiz.id, nil, nil, nil, -1, @session_id,
+                               @study_participant, nil)
+    end
 end
diff --git a/app/models/reader.rb b/app/models/reader.rb
index a49c6c407..0ba906da7 100644
--- a/app/models/reader.rb
+++ b/app/models/reader.rb
@@ -2,6 +2,6 @@
 # Reader keeps track of when a user hast last seen a certain thread,
 # making it possible to display whether there are new comments
 class Reader < ApplicationRecord
-	belongs_to :user
-	belongs_to :thread, class_name: 'Commontator::Thread'
+  belongs_to :user
+  belongs_to :thread, class_name: 'Commontator::Thread'
 end
diff --git a/app/models/referral.rb b/app/models/referral.rb
index 8040a6083..ecf3e6f32 100644
--- a/app/models/referral.rb
+++ b/app/models/referral.rb
@@ -22,6 +22,7 @@ class Referral < ApplicationRecord
   # otherwise, return the item's explanation
   def explain
     return explanation if item.nil?
+
     explanation || item.explanation
   end
 
@@ -104,51 +105,56 @@ def item_in_quarantine?
 
   private
 
-  # explanation provided to the vtt file
-  # returns the referral's explanation if present, the item's explanation
-  # if the item is a link, otherwise nil
-  def vtt_explanation
-    return explanation if explanation.present?
-    return item.explanation if item.sort == 'link' && item.explanation.present?
-  end
+    # explanation provided to the vtt file
+    # returns the referral's explanation if present, the item's explanation
+    # if the item is a link, otherwise nil
+    def vtt_explanation
+      return explanation if explanation.present?
+      return item.explanation if item.sort == 'link' && item.explanation.present?
+    end
 
-  # some method that check for valid start and end time
+    # some method that check for valid start and end time
 
-  def valid_start_time
-    return true if start_time.nil?
-    return true if start_time.valid?
-    errors.add(:start_time, :invalid_format)
-    false
-  end
+    def valid_start_time
+      return true if start_time.nil?
+      return true if start_time.valid?
 
-  def valid_end_time
-    return true if end_time.nil?
-    return true if end_time.valid?
-    errors.add(:end_time, :invalid_format)
-    false
-  end
+      errors.add(:start_time, :invalid_format)
+      false
+    end
 
-  def start_time_not_too_late
-    return true if medium.nil? || !medium.video
-    return true unless start_time.valid?
-    return true if start_time.total_seconds <= medium.video_duration
-    errors.add(:start_time, :too_late)
-    false
-  end
+    def valid_end_time
+      return true if end_time.nil?
+      return true if end_time.valid?
 
-  def end_time_not_too_late
-    return true if medium.nil? || !medium.video
-    return true unless end_time.valid?
-    return true if end_time.total_seconds <= medium.video_duration
-    errors.add(:end_time, :too_late)
-    false
-  end
+      errors.add(:end_time, :invalid_format)
+      false
+    end
 
-  def end_time_not_too_soon
-    return true unless start_time&.valid?
-    return true unless end_time&.valid?
-    return true if start_time.total_seconds < end_time.total_seconds
-    errors.add(:end_time, :too_soon)
-    false
-  end
+    def start_time_not_too_late
+      return true if medium.nil? || !medium.video
+      return true unless start_time.valid?
+      return true if start_time.total_seconds <= medium.video_duration
+
+      errors.add(:start_time, :too_late)
+      false
+    end
+
+    def end_time_not_too_late
+      return true if medium.nil? || !medium.video
+      return true unless end_time.valid?
+      return true if end_time.total_seconds <= medium.video_duration
+
+      errors.add(:end_time, :too_late)
+      false
+    end
+
+    def end_time_not_too_soon
+      return true unless start_time&.valid?
+      return true unless end_time&.valid?
+      return true if start_time.total_seconds < end_time.total_seconds
+
+      errors.add(:end_time, :too_soon)
+      false
+    end
 end
diff --git a/app/models/relation.rb b/app/models/relation.rb
index 533eada78..a3775e48e 100644
--- a/app/models/relation.rb
+++ b/app/models/relation.rb
@@ -13,32 +13,33 @@ class Relation < ApplicationRecord
 
   private
 
-  def create_inverse
-    self.class.create(inverse_relation_options)
-  end
-
-  def destroy_inverses
-    inverses.destroy_all
-  end
-
-  def self_inverse?
-    tag_id == related_tag_id
-  end
-
-  def inverse?
-    self.class.exists?(inverse_relation_options) || self_inverse?
-  end
-
-  def inverses
-    self.class.where(inverse_relation_options)
-  end
-
-  def inverse_relation_options
-    { related_tag_id: tag_id, tag_id: related_tag_id }
-  end
-
-  def touch_tag
-    return if tag.nil?
-    tag.touch
-  end
+    def create_inverse
+      self.class.create(inverse_relation_options)
+    end
+
+    def destroy_inverses
+      inverses.destroy_all
+    end
+
+    def self_inverse?
+      tag_id == related_tag_id
+    end
+
+    def inverse?
+      self.class.exists?(inverse_relation_options) || self_inverse?
+    end
+
+    def inverses
+      self.class.where(inverse_relation_options)
+    end
+
+    def inverse_relation_options
+      { related_tag_id: tag_id, tag_id: related_tag_id }
+    end
+
+    def touch_tag
+      return if tag.nil?
+
+      tag.touch
+    end
 end
diff --git a/app/models/section.rb b/app/models/section.rb
index ff4e30f9c..e6287dcfe 100644
--- a/app/models/section.rb
+++ b/app/models/section.rb
@@ -15,7 +15,7 @@ class Section < ApplicationRecord
   # a section has many lessons
   has_many :lesson_section_joins, dependent: :destroy
   has_many :lessons, -> { order(date: :asc, id: :asc) },
-                     through: :lesson_section_joins
+           through: :lesson_section_joins
 
   # a section needs to have a title
   validates :title, presence: true
@@ -42,6 +42,7 @@ def lecture
 
   def reference_number
     return calculated_number unless display_number.present?
+
     display_number
   end
 
@@ -61,11 +62,13 @@ def reference
   def calculated_number
     return relative_position unless lecture.absolute_numbering
     return absolute_position.to_s unless lecture.start_section.present?
+
     (absolute_position + lecture.start_section - 1).to_s
   end
 
   def to_label
     return displayed_number + '. ' + title unless hidden_with_inheritance?
+
     '*' + displayed_number + '. ' + title
   end
 
@@ -75,7 +78,7 @@ def media
     lessons.map(&:media).flatten
   end
 
-   # visible media are published with inheritance and unlocked
+  # visible media are published with inheritance and unlocked
   def visible_media_for_user(user)
     media.select { |m| m.visible_for_user?(user) }
   end
@@ -85,6 +88,7 @@ def visible_for_user?(user)
     return true if lecture.edited_by?(user)
     return false unless lecture.published?
     return false unless lecture.visible_for_user?(user)
+
     true
   end
 
@@ -92,8 +96,10 @@ def previous_preliminary
     return higher_item unless first?
     return if chapter.first?
     return unless previous_chapter
+
     potential_last = previous_chapter.sections.last
     return potential_last if potential_last.last?
+
     potential_last.lower_items.last
   end
 
@@ -112,8 +118,10 @@ def next_preliminary
     return lower_item unless last?
     return if chapter.last?
     return unless next_chapter
+
     potential_first = next_chapter.sections.first
     return potential_first if potential_first.first?
+
     potential_first.higher_items.first
   end
 
@@ -150,6 +158,7 @@ def visible_items_by_time
 
   def visible_items
     return visible_items_by_time if lecture.content_mode == 'video'
+
     script_items_by_position
   end
 
@@ -166,48 +175,51 @@ def duplicate_in_chapter(new_chapter, import_tags)
     new_section.chapter = new_chapter
     new_section.save
     return unless import_tags
+
     new_section.update(tags_order: tags_order)
     new_section.tags << tags
   end
 
   private
 
-  def touch_lecture
-    return unless lecture.present? && lecture.persisted?
-    lecture.touch
-  end
+    def touch_lecture
+      return unless lecture.present? && lecture.persisted?
 
-  def touch_media
-    lecture.media_with_inheritance.update_all(updated_at: Time.current)
-    touch
-  end
+      lecture.touch
+    end
 
-  def touch_self
-    touch
-  end
+    def touch_media
+      lecture.media_with_inheritance.update_all(updated_at: Time.current)
+      touch
+    end
 
-  def touch_toc
-    return unless lecture.absolute_numbering
-    lecture.chapters.update_all(updated_at: Time.now)
-    lecture.sections.update_all(updated_at: Time.now)
-  end
+    def touch_self
+      touch
+    end
 
-  def relative_position
-    chapter.displayed_number + '.' + position.to_s
-  end
+    def touch_toc
+      return unless lecture.absolute_numbering
 
-  def absolute_position
-    chapter.higher_items.includes(:sections).map(&:sections).flatten.size +
-      position
-  end
+      lecture.chapters.update_all(updated_at: Time.now)
+      lecture.sections.update_all(updated_at: Time.now)
+    end
 
-  def next_chapter
-    # actual next chapter may not have any sections
-    chapter.lower_items.find { |c| c.sections.exists? }
-  end
+    def relative_position
+      chapter.displayed_number + '.' + position.to_s
+    end
 
-  def previous_chapter
-    # actual previous chapter may not have any sections
-    chapter.higher_items.find { |c| c.sections.exists? }
-  end
+    def absolute_position
+      chapter.higher_items.includes(:sections).map(&:sections).flatten.size +
+        position
+    end
+
+    def next_chapter
+      # actual next chapter may not have any sections
+      chapter.lower_items.find { |c| c.sections.exists? }
+    end
+
+    def previous_chapter
+      # actual previous chapter may not have any sections
+      chapter.higher_items.find { |c| c.sections.exists? }
+    end
 end
diff --git a/app/models/section_tag_join.rb b/app/models/section_tag_join.rb
index a8ccf4477..24055766b 100644
--- a/app/models/section_tag_join.rb
+++ b/app/models/section_tag_join.rb
@@ -1,7 +1,7 @@
 # SectionTagJoin class
 # Join table for section<->tag many-to-many-relation
 class SectionTagJoin < ApplicationRecord
-	default_scope { order :tag_position }
+  default_scope { order :tag_position }
   belongs_to :section
   belongs_to :tag
   acts_as_list scope: :section, top_of_list: 0, column: :tag_position
diff --git a/app/models/solution.rb b/app/models/solution.rb
index 2d108888c..010ca8f2d 100644
--- a/app/models/solution.rb
+++ b/app/models/solution.rb
@@ -33,19 +33,22 @@ def nerd
 
   def tex
     return '' unless @content.tex
+
     '$$' + @content.tex + '$$'
   end
 
   def tex_mc_answer
     return '' unless @content.tex
+
     '$' + @content.tex + '$'
   end
 
   def self.from_hash(solution_type, content)
     return unless solution_type.in?(['MampfExpression', 'MampfMatrix',
                                      'MampfTuple', 'MampfSet'])
+
     solution = Solution.new(solution_type.constantize.from_hash(content))
     solution.explanation = content[:explanation]
     solution
   end
-end
\ No newline at end of file
+end
diff --git a/app/models/subject.rb b/app/models/subject.rb
index 063b651a7..110504013 100644
--- a/app/models/subject.rb
+++ b/app/models/subject.rb
@@ -1,9 +1,9 @@
 class Subject < ApplicationRecord
-	has_many :programs
+  has_many :programs
 
-	translates :name
-	globalize_accessors locales: I18n.available_locales,
-											attributes: translated_attribute_names
+  translates :name
+  globalize_accessors locales: I18n.available_locales,
+                      attributes: translated_attribute_names
 
   def deletable?
     programs.none?
diff --git a/app/models/submission.rb b/app/models/submission.rb
index 11d0e5fc8..8b352da41 100644
--- a/app/models/submission.rb
+++ b/app/models/submission.rb
@@ -18,50 +18,56 @@ class Submission < ApplicationRecord
 
   def partners_of_user(user)
     return unless user.in?(users)
+
     users - [user]
   end
 
   def team
-  	users.map(&:tutorial_name).natural_sort.join(', ')
+    users.map(&:tutorial_name).natural_sort.join(', ')
   end
 
   def manuscript_filename
     return unless manuscript.present?
+
     manuscript.metadata['filename']
   end
 
   def manuscript_size
     return unless manuscript.present?
+
     manuscript.metadata['size']
   end
 
   def manuscript_mime_type
-		return unless manuscript.present?
+    return unless manuscript.present?
+
     manuscript.metadata['mime_type']
   end
 
   def correction_filename
     return unless correction.present?
+
     correction.metadata['filename']
   end
 
   def correction_mime_type
-		return unless correction.present?
+    return unless correction.present?
+
     correction.metadata['mime_type']
   end
 
   def correction_size
     return unless correction.present?
+
     correction.metadata['size']
   end
 
-
   def preceding_tutorial(user)
     assignment.previous&.map { |a| a.tutorial(user) }&.compact&.first
   end
 
   def invited_users
-  	User.where(id: invited_user_ids)
+    User.where(id: invited_user_ids)
   end
 
   def self.generate_token
@@ -72,7 +78,7 @@ def self.generate_token
   end
 
   def admissible_invitees(user)
-  	user.submission_partners(assignment.lecture) - users
+    user.submission_partners(assignment.lecture) - users
   end
 
   def in_time?
@@ -85,32 +91,33 @@ def too_late?
 
   def not_updatable?
     return false if assignment.active?
+
     assignment.totally_expired? || correction.present? || accepted == false
   end
 
-  #def file_path(downloadable)
+  # def file_path(downloadable)
   #	return unless manuscript
   # 	manuscript.to_io.path
   # end
 
-  #def correction_file_path
+  # def correction_file_path
   #  return unless correction
   #  correction.to_io.path
-  #end
-
-  def filename_for_bulk_download(end_of_file='')
-		(team.first(180) + '-' +
-			last_modification_by_users_at.strftime("%F-%H%M") +
-			(too_late? ? '-LATE' : '') +
-			+ '-ID-' + id + end_of_file +
-			assignment.accepted_file_type)
-			.gsub(/[\x00\/\\:\*\?\"<>\|]/, '_')
-	   	.gsub(/^.*(\\|\/)/, '')
-   		# Strip out the non-ascii characters
-   		.gsub(/[^0-9A-Za-z.\-]/, '_')
+  # end
+
+  def filename_for_bulk_download(end_of_file = '')
+    (team.first(180) + '-' +
+      last_modification_by_users_at.strftime("%F-%H%M") +
+      (too_late? ? '-LATE' : '') +
+      + '-ID-' + id + end_of_file +
+      assignment.accepted_file_type)
+      .gsub(/[\x00\/\\:\*\?\"<>\|]/, '_')
+      .gsub(/^.*(\\|\/)/, '')
+      # Strip out the non-ascii characters
+      .gsub(/[^0-9A-Za-z.\-]/, '_')
   end
 
-  def self.zip(submissions, downloadables, end_of_file='')
+  def self.zip(submissions, downloadables, end_of_file = '')
     begin
       archived_filestream = Zip::OutputStream.write_buffer do |stream|
         submissions.zip(downloadables).each do |s, d|
@@ -128,85 +135,91 @@ def self.zip(submissions, downloadables, end_of_file='')
   def self.zip_submissions!(tutorial, assignment)
     submissions = Submission.where(tutorial: tutorial,
                                    assignment: assignment).proper
-    manuscripts = submissions.collect { |s| s.manuscript if s.manuscript.present? }
+    manuscripts = submissions.collect { |s|
+      s.manuscript if s.manuscript.present?
+    }
     zip(submissions, manuscripts)
   end
 
   def self.zip_corrections!(tutorial, assignment)
     submissions = Submission.where(tutorial: tutorial,
                                    assignment: assignment).proper
-    corrections = submissions.collect { |s| s.correction if s.correction.present? }
+    corrections = submissions.collect { |s|
+      s.correction if s.correction.present?
+    }
 
     zip(submissions, corrections, '-correction')
   end
 
-
   ###
   # Checks size and if filetype is acceptable
   ###
   def check_file_properties_any(metadata, sort)
     errors = []
-    if sort == :submission && metadata['size'] > 10*1024*1024
+    if sort == :submission && metadata['size'] > 10 * 1024 * 1024
       errors.push I18n.t('submission.manuscript_size_too_big',
                          max_size: '10 MB')
     end
-    if sort == :correction && metadata['size'] > 15*1024*1024
+    if sort == :correction && metadata['size'] > 15 * 1024 * 1024
       errors.push I18n.t('submission.manuscript_size_too_big',
                          max_size: '15 MB')
     end
     file_name = metadata['filename']
     file_type = File.extname(file_name)
-    if !file_type.in?(['.cc', '.hh', '.m',".mlx", '.pdf', '.zip',".txt"])
+    if !file_type.in?(['.cc', '.hh', '.m', ".mlx", '.pdf', '.zip', ".txt"])
       errors.push I18n.t('submission.wrong_file_type',
                          file_type: file_type,
                          accepted_file_type: assignment.accepted_file_type)
     end
     return {} unless errors.present?
+
     { sort => errors }
   end
+
   def check_file_properties(metadata, sort)
     errors = []
-    if sort == :submission && metadata['size'] > 10*1024*1024
+    if sort == :submission && metadata['size'] > 10 * 1024 * 1024
       errors.push I18n.t('submission.manuscript_size_too_big',
                          max_size: '10 MB')
     end
-    if sort == :correction && metadata['size'] > 15*1024*1024
+    if sort == :correction && metadata['size'] > 15 * 1024 * 1024
       errors.push I18n.t('submission.manuscript_size_too_big',
                          max_size: '15 MB')
     end
     file_name = metadata['filename']
     file_type = File.extname(file_name)
     if file_type != assignment.accepted_file_type &&
-      assignment.accepted_file_type != '.tar.gz'
+       assignment.accepted_file_type != '.tar.gz'
       errors.push I18n.t('submission.wrong_file_type',
                          file_type: file_type,
                          accepted_file_type: assignment.accepted_file_type)
     end
     if assignment.accepted_file_type == '.tar.gz'
-    	if file_type == '.gz'
-    		reduced_type = File.extname(File.basename(file_name, '.gz'))
-    		if reduced_type != '.tar'
-					errors.push I18n.t('submission.wrong_file_type',
-                      			 file_type: '.gz',
-                      			 accepted_file_type: '.tar.gz')
+      if file_type == '.gz'
+        reduced_type = File.extname(File.basename(file_name, '.gz'))
+        if reduced_type != '.tar'
+          errors.push I18n.t('submission.wrong_file_type',
+                             file_type: '.gz',
+                             accepted_file_type: '.tar.gz')
         end
       else
-				errors.push I18n.t('submission.wrong_file_type',
-                      		 file_type: file_type,
-                     	 		 accepted_file_type: '.tar.gz')
-			end
+        errors.push I18n.t('submission.wrong_file_type',
+                           file_type: file_type,
+                           accepted_file_type: '.tar.gz')
+      end
     end
     if (!assignment.accepted_file_type.in?(['.cc', '.hh', '.m']) &&
       !metadata['mime_type'].in?(assignment.accepted_mime_types)) ||
-      (assignment.accepted_file_type.in?(['.cc', '.hh', '.m']) &&
-        (!metadata['mime_type'].starts_with?('text/') &&
-         metadata['mime_type'] != 'application/octet-stream'))
+       (assignment.accepted_file_type.in?(['.cc', '.hh', '.m']) &&
+         (!metadata['mime_type'].starts_with?('text/') &&
+          metadata['mime_type'] != 'application/octet-stream'))
       errors.push I18n.t('submission.wrong_mime_type',
-                          mime_type: metadata['mime_type'],
-                          accepted_mime_types: assignment.accepted_mime_types
-                                                         .join(', '))
+                         mime_type: metadata['mime_type'],
+                         accepted_mime_types: assignment.accepted_mime_types
+                                                        .join(', '))
     end
     return {} unless errors.present?
+
     { sort => errors }
   end
 
@@ -214,7 +227,7 @@ def self.bulk_corrections!(tutorial, assignment, files)
     submissions = Submission.where(tutorial: tutorial,
                                    assignment: assignment).proper
     report = { successful_saves: [], submissions: submissions.size,
-    					 invalid_filenames: [], invalid_id: [], in_subfolder: [],
+               invalid_filenames: [], invalid_id: [], in_subfolder: [],
                no_decision: [], rejected: [], invalid_file: [] }
     tmp_folder = Dir.mktmpdir
     begin
@@ -225,7 +238,7 @@ def self.bulk_corrections!(tutorial, assignment, files)
           next
         end
         submission_id = File.basename(filename.split('-ID-').last,
-                                        File.extname(filename.split('-ID-').last))
+                                      File.extname(filename.split('-ID-').last))
         submission = Submission.find_by_id(submission_id)
         if !submission
           report[:invalid_id].push(filename)
@@ -254,44 +267,45 @@ def self.bulk_corrections!(tutorial, assignment, files)
 
   private
 
-  def matching_lecture
-    return true if tutorial&.lecture == assignment&.lecture
-    errors.add(:tutorial, :lecture_not_matching)
-  end
+    def matching_lecture
+      return true if tutorial&.lecture == assignment&.lecture
 
-  def set_token
-    self.token = Submission.generate_token
-  end
+      errors.add(:tutorial, :lecture_not_matching)
+    end
 
-  def self.number_of_submissions(tutorial, assignment)
-    Submission.where(tutorial: tutorial, assignment: assignment)
-              .where.not(manuscript_data: nil).size
-  end
+    def set_token
+      self.token = Submission.generate_token
+    end
 
-  def self.number_of_corrections(tutorial, assignment)
-    Submission.where(tutorial: tutorial, assignment: assignment)
-              .where.not(correction_data: nil).size
-  end
+    def self.number_of_submissions(tutorial, assignment)
+      Submission.where(tutorial: tutorial, assignment: assignment)
+                .where.not(manuscript_data: nil).size
+    end
 
-  def self.number_of_late_submissions(tutorial, assignment)
-    Submission.where(tutorial: tutorial, assignment: assignment)
-              .where.not(manuscript_data: nil)
-              .select { |s| s.too_late? }.size
-  end
+    def self.number_of_corrections(tutorial, assignment)
+      Submission.where(tutorial: tutorial, assignment: assignment)
+                .where.not(correction_data: nil).size
+    end
 
-  def self.submissions_total(assignment)
-    Submission.where(assignment: assignment)
-              .where.not(manuscript_data: nil).size
-  end
+    def self.number_of_late_submissions(tutorial, assignment)
+      Submission.where(tutorial: tutorial, assignment: assignment)
+                .where.not(manuscript_data: nil)
+                .select { |s| s.too_late? }.size
+    end
 
-  def self.corrections_total(assignment)
-    Submission.where(assignment: assignment)
-              .where.not(correction_data: nil).size
-  end
+    def self.submissions_total(assignment)
+      Submission.where(assignment: assignment)
+                .where.not(manuscript_data: nil).size
+    end
 
-  def self.late_submissions_total(assignment)
-    Submission.where(assignment: assignment)
-              .where.not(manuscript_data: nil)
-              .select { |s| s.too_late? }.size
-  end
+    def self.corrections_total(assignment)
+      Submission.where(assignment: assignment)
+                .where.not(correction_data: nil).size
+    end
+
+    def self.late_submissions_total(assignment)
+      Submission.where(assignment: assignment)
+                .where.not(manuscript_data: nil)
+                .select { |s| s.too_late? }.size
+    end
 end
diff --git a/app/models/submission_cleaner.rb b/app/models/submission_cleaner.rb
index 9f4e7681f..5a91644cc 100644
--- a/app/models/submission_cleaner.rb
+++ b/app/models/submission_cleaner.rb
@@ -50,75 +50,75 @@ def check_for_deletion
 
   private
 
-  def clear_props
-    @assignments = nil
-    @submitters = nil
-    @lectures = nil
-  end
+    def clear_props
+      @assignments = nil
+      @submitters = nil
+      @lectures = nil
+    end
 
-  def fetch_props
-    clear_props
-    @assignments = Assignment.where(deletion_date: @deletion_date)
-    return if @assignments.empty?
+    def fetch_props
+      clear_props
+      @assignments = Assignment.where(deletion_date: @deletion_date)
+      return if @assignments.empty?
 
-    @submitters = User.where(id: @assignments.flat_map(&:submitter_ids))
-    @lectures = Lecture.where(id: @assignments.pluck(:lecture_id))
-  end
+      @submitters = User.where(id: @assignments.flat_map(&:submitter_ids))
+      @lectures = Lecture.where(id: @assignments.pluck(:lecture_id))
+    end
 
-  def send_destruction_mail_to_submitters
-    return if @submitters.blank?
+    def send_destruction_mail_to_submitters
+      return if @submitters.blank?
 
-    I18n.available_locales.each do |l|
-      local_submitter_ids = @submitters.where(locale: l).pluck(:id)
-      next if local_submitter_ids.empty?
+      I18n.available_locales.each do |l|
+        local_submitter_ids = @submitters.where(locale: l).pluck(:id)
+        next if local_submitter_ids.empty?
 
-      local_submitter_ids.in_groups_of(200, false) do |group|
-        NotificationMailer.with(recipients: group,
-                                deletion_date: @deletion_date,
-                                locale: l)
-                          .submission_destruction_email.deliver_now
+        local_submitter_ids.in_groups_of(200, false) do |group|
+          NotificationMailer.with(recipients: group,
+                                  deletion_date: @deletion_date,
+                                  locale: l)
+                            .submission_destruction_email.deliver_now
+        end
       end
     end
-  end
 
-  def send_destruction_mail_to_editors
-    @lectures.each do |l|
-      editor_ids = l.editors.pluck(:id) + [l.teacher.id]
-      NotificationMailer.with(recipients: editor_ids,
-                              lecture: l,
-                              deletion_date: @deletion_date,
-                              locale: l.locale)
-                        .submission_destruction_lecture_email.deliver_now
+    def send_destruction_mail_to_editors
+      @lectures.each do |l|
+        editor_ids = l.editors.pluck(:id) + [l.teacher.id]
+        NotificationMailer.with(recipients: editor_ids,
+                                lecture: l,
+                                deletion_date: @deletion_date,
+                                locale: l.locale)
+                          .submission_destruction_lecture_email.deliver_now
+      end
     end
-  end
-
-  def send_info_mail_to_submitters
-    return if @submitters.blank?
 
-    I18n.available_locales.each do |l|
-      local_submitter_ids = @submitters.where(locale: l).pluck(:id)
-      next if local_submitter_ids.empty?
+    def send_info_mail_to_submitters
+      return if @submitters.blank?
+
+      I18n.available_locales.each do |l|
+        local_submitter_ids = @submitters.where(locale: l).pluck(:id)
+        next if local_submitter_ids.empty?
+
+        local_submitter_ids.in_groups_of(200, false) do |group|
+          NotificationMailer.with(recipients: group,
+                                  deletion_date: @deletion_date,
+                                  reminder: @reminder,
+                                  lectures: @lectures,
+                                  locale: l)
+                            .submission_deletion_email.deliver_now
+        end
+      end
+    end
 
-      local_submitter_ids.in_groups_of(200, false) do |group|
-        NotificationMailer.with(recipients: group,
+    def send_info_mail_to_editors
+      @lectures.each do |l|
+        editor_ids = l.editors.pluck(:id) + [l.teacher.id]
+        NotificationMailer.with(recipients: editor_ids,
+                                lecture: l,
                                 deletion_date: @deletion_date,
                                 reminder: @reminder,
-                                lectures: @lectures,
-                                locale: l)
-                          .submission_deletion_email.deliver_now
+                                locale: l.locale)
+                          .submission_deletion_lecture_email.deliver_now
       end
     end
-  end
-
-  def send_info_mail_to_editors
-    @lectures.each do |l|
-      editor_ids = l.editors.pluck(:id) + [l.teacher.id]
-      NotificationMailer.with(recipients: editor_ids,
-                              lecture: l,
-                              deletion_date: @deletion_date,
-                              reminder: @reminder,
-                              locale: l.locale)
-                        .submission_deletion_lecture_email.deliver_now
-    end
-  end
 end
diff --git a/app/models/tag.rb b/app/models/tag.rb
index dc37e6361..42d1499a0 100644
--- a/app/models/tag.rb
+++ b/app/models/tag.rb
@@ -38,15 +38,19 @@ class Tag < ApplicationRecord
   serialize :realizations, Array
 
   accepts_nested_attributes_for :notions,
-    reject_if: lambda {|attributes| attributes['title'].blank?},
-    allow_destroy: true
+                                reject_if: lambda { |attributes|
+                                             attributes['title'].blank?
+                                           },
+                                allow_destroy: true
 
   validates_presence_of :notions
   validates_associated :notions
 
   accepts_nested_attributes_for :aliases,
-    reject_if: lambda {|attributes| attributes['title'].blank?},
-    allow_destroy: true
+                                reject_if: lambda { |attributes|
+                                             attributes['title'].blank?
+                                           },
+                                allow_destroy: true
 
   validates_associated :aliases
 
@@ -84,6 +88,7 @@ def extended_title_uncached
     unless other_titles_uncached.any?
       return local_title_uncached + " (#{aliases.pluck(:title).join(', ')})"
     end
+
     local_title_uncached +
       " (#{aliases.pluck(:title).join(', ')}," +
       " #{other_titles_uncached.join(', ')})"
@@ -144,7 +149,6 @@ def self.select_with_substring(search_string)
                    .map { |t| { value: t.id, text: t.title } }
   end
 
-
   # returns all tags whose title is close to the given search string
   # wrt to the JaroWinkler metric
   def self.similar_tags(search_string)
@@ -174,7 +178,7 @@ def self.select_by_title
   def self.select_by_title_except(excluded_tags)
     Tag.where.not(id: excluded_tags.pluck(:id))
        .map { |t| t.extended_title_id_hash }
-       .natural_sort_by{ |t| t[:title] }.map { |t| [t[:title], t[:id]] }
+       .natural_sort_by { |t| t[:title] }.map { |t| [t[:title], t[:id]] }
   end
 
   # converts the subgraph of all tags of distance <= 2 to the given marked tag
@@ -208,6 +212,7 @@ def realizations_cached
   # search params is a hash having keys :all_tags, :tag_ids
   def self.search_tags(search_params)
     return Tag.all unless search_params[:all_tags] == '0'
+
     tag_ids = search_params[:tag_ids] || []
     Tag.where(id: tag_ids)
   end
@@ -238,6 +243,7 @@ def tags_in_neighbourhood
 
   def short_title(max_letters = 30)
     return title unless title.length > max_letters
+
     title[0, max_letters - 3] + '...'
   end
 
@@ -265,6 +271,7 @@ def lectures
   def create_random_quiz!(user)
     questions = visible_questions(user)
     return unless questions.any?
+
     question_ids = questions.pluck(:id).sample(5)
     quiz_graph = QuizGraph.build_from_questions(question_ids)
     quiz = Quiz.new(description: "#{I18n.t('categories.randomquiz.singular')} #{title} #{Time.now}",
@@ -273,6 +280,7 @@ def create_random_quiz!(user)
                     sort: 'RandomQuiz')
     quiz.save
     return quiz.errors unless quiz.valid?
+
     quiz
   end
 
@@ -281,6 +289,7 @@ def create_random_quiz!(user)
   def color(marked_tag, highlight_related_tags: true)
     return '#f00' if self == marked_tag
     return '#ff8c00' if highlight_related_tags && in?(marked_tag.related_tags)
+
     '#000'
   end
 
@@ -289,6 +298,7 @@ def color(marked_tag, highlight_related_tags: true)
   def background(marked_tag, highlight_related_tags: true)
     return '#f00' if self == marked_tag
     return '#ff8c00' if highlight_related_tags && in?(marked_tag.related_tags)
+
     '#666'
   end
 
@@ -313,7 +323,9 @@ def cytoscape_edge(related_tag)
 
   # published sections are sections that belong to a published lecture
   def visible_sections(user)
-    user.filter_sections(sections).select { |s| s.lecture.visible_for_user?(user) }
+    user.filter_sections(sections).select { |s|
+      s.lecture.visible_for_user?(user)
+    }
   end
 
   def cache_key
@@ -343,6 +355,7 @@ def identify_with!(tag)
     related_tags.delete(tag)
     tag.sections.each do |s|
       next unless self.in?(s.tags)
+
       old_section_tag = SectionTagJoin.find_by(section: s, tag: tag)
       position = old_section_tag.tag_position
       new_section_tag = SectionTagJoin.find_by(section: s, tag: self)
@@ -369,24 +382,25 @@ def visible_questions(user)
 
   private
 
-  def touch_relations(notion)
-    if persisted?
-      touch
-      touch_lectures
-      touch_sections
-      touch_chapters
+    def touch_relations(notion)
+      if persisted?
+        touch
+        touch_lectures
+        touch_sections
+        touch_chapters
+      end
     end
-  end
 
-  # simulates the after_destroy callback for relations
-  def destroy_relations(related_tag)
-    Relation.where(tag: [self, related_tag],
-                   related_tag: [self, related_tag]).delete_all
-  end
+    # simulates the after_destroy callback for relations
+    def destroy_relations(related_tag)
+      Relation.where(tag: [self, related_tag],
+                     related_tag: [self, related_tag]).delete_all
+    end
 
-  def title_join
-    result = notions.pluck(:title).join(' ')
-    return result unless aliases.any?
-    result + ' ' + aliases.pluck(:title).join(' ')
-  end
+    def title_join
+      result = notions.pluck(:title).join(' ')
+      return result unless aliases.any?
+
+      result + ' ' + aliases.pluck(:title).join(' ')
+    end
 end
diff --git a/app/models/talk.rb b/app/models/talk.rb
index e34fbf05e..5b528e139 100644
--- a/app/models/talk.rb
+++ b/app/models/talk.rb
@@ -8,7 +8,7 @@ class Talk < ApplicationRecord
 
   # being a teachable (course/lecture/lesson), a talk has associated media
   has_many :media, -> { order(position: :asc) }, as: :teachable,
-           dependent: :destroy
+                                                 dependent: :destroy
 
   # a talk has many tags
   has_many :talk_tag_joins, dependent: :destroy
diff --git a/app/models/term.rb b/app/models/term.rb
index 43279cd49..36009cad4 100644
--- a/app/models/term.rb
+++ b/app/models/term.rb
@@ -41,6 +41,7 @@ def end_date
   # label contains season and year(s) with all digits
   def to_label
     return unless season.present?
+
     season + ' ' + year_corrected
   end
 
@@ -101,12 +102,15 @@ def self.possible_deletion_dates
   end
 
   def self.possible_deletion_dates_localized
-    possible_deletion_dates.map { |d| d.strftime(I18n.t('date.formats.concise')) }
+    possible_deletion_dates.map { |d|
+      d.strftime(I18n.t('date.formats.concise'))
+    }
   end
 
   # array of all terms together with their ids for use in options_for_select
   def self.select_terms(independent = false)
     return ['bla', nil] if independent
+
     Term.all.sort_by(&:begin_date).reverse.map { |t| [t.to_label, t.id] }
   end
 
@@ -120,24 +124,26 @@ def self.previous_by_date(date)
 
   private
 
-  def year_corrected
-    return year.to_s unless season == 'WS'
-    year.to_s + '/' + ((year % 100) + 1).to_s
-  end
+    def year_corrected
+      return year.to_s unless season == 'WS'
 
-  def year_corrected_short
-    return (year % 100).to_s unless season == 'WS'
-    (year % 100).to_s + '/' + ((year % 100) + 1).to_s
-  end
+      year.to_s + '/' + ((year % 100) + 1).to_s
+    end
 
-  def touch_lectures_and_lessons
-    lectures.update_all(updated_at: Time.now)
-    Lesson.where(lecture: lectures).update_all(updated_at: Time.now)
-  end
+    def year_corrected_short
+      return (year % 100).to_s unless season == 'WS'
 
-  def touch_media
-    Medium.where(teachable: lectures).update_all(updated_at: Time.now)
-    Medium.where(teachable: Lesson.where(lecture: lectures))
-          .update_all(updated_at: Time.now)
-  end
+      (year % 100).to_s + '/' + ((year % 100) + 1).to_s
+    end
+
+    def touch_lectures_and_lessons
+      lectures.update_all(updated_at: Time.now)
+      Lesson.where(lecture: lectures).update_all(updated_at: Time.now)
+    end
+
+    def touch_media
+      Medium.where(teachable: lectures).update_all(updated_at: Time.now)
+      Medium.where(teachable: Lesson.where(lecture: lectures))
+            .update_all(updated_at: Time.now)
+    end
 end
diff --git a/app/models/time_stamp.rb b/app/models/time_stamp.rb
index d5232735c..1924e36bb 100644
--- a/app/models/time_stamp.rb
+++ b/app/models/time_stamp.rb
@@ -81,27 +81,28 @@ def total_seconds
 
   private
 
-  def init_with_total_seconds(total_s)
-    floor_s = total_s.floor
-    @milliseconds = ((total_s - floor_s) * 1000).round
-    @minutes = (floor_s / 60) % 60
-    @seconds = floor_s % 60
-    @hours = floor_s / (60 * 60)
-  end
+    def init_with_total_seconds(total_s)
+      floor_s = total_s.floor
+      @milliseconds = ((total_s - floor_s) * 1000).round
+      @minutes = (floor_s / 60) % 60
+      @seconds = floor_s % 60
+      @hours = floor_s / (60 * 60)
+    end
 
-  def init_with_time_string(time_string)
-    return unless /(\d+):([0-5]\d):([0-5]\d).(\d{3})/.match?(time_string)
-    matchdata = /(\d):([0-5]\d):([0-5]\d).(\d{3})/.match(time_string)
-    @hours = matchdata[1].to_i
-    @minutes = matchdata[2].to_i
-    @seconds = matchdata[3].to_i
-    @milliseconds = matchdata[4].to_i
-  end
+    def init_with_time_string(time_string)
+      return unless /(\d+):([0-5]\d):([0-5]\d).(\d{3})/.match?(time_string)
 
-  def init_with_hms(params)
-    @hours = params[:h].to_i
-    @minutes = params[:m].to_i
-    @seconds = params[:s].to_i
-    @milliseconds = params[:ms].to_i
-  end
+      matchdata = /(\d):([0-5]\d):([0-5]\d).(\d{3})/.match(time_string)
+      @hours = matchdata[1].to_i
+      @minutes = matchdata[2].to_i
+      @seconds = matchdata[3].to_i
+      @milliseconds = matchdata[4].to_i
+    end
+
+    def init_with_hms(params)
+      @hours = params[:h].to_i
+      @minutes = params[:m].to_i
+      @seconds = params[:s].to_i
+      @milliseconds = params[:ms].to_i
+    end
 end
diff --git a/app/models/tutorial.rb b/app/models/tutorial.rb
index b093de301..60611c8a7 100644
--- a/app/models/tutorial.rb
+++ b/app/models/tutorial.rb
@@ -14,20 +14,21 @@ class Tutorial < ApplicationRecord
   validates :title, uniqueness: { scope: [:lecture_id] }, presence: true
 
   def title_with_tutors
-  	return "#{title}, #{I18n.t('basics.tba')}" unless tutors.any?
-  	"#{title}, #{tutor_names}"
+    return "#{title}, #{I18n.t('basics.tba')}" unless tutors.any?
+
+    "#{title}, #{tutor_names}"
   end
 
   def tutor_names
-  	return unless tutors.any?
-  	tutors.map(&:tutorial_name).join(', ')
+    return unless tutors.any?
+
+    tutors.map(&:tutorial_name).join(', ')
   end
 
   def destructible?
-		Submission.where(tutorial: self).proper.none?
+    Submission.where(tutorial: self).proper.none?
   end
 
-
   def teams_to_csv(assignment)
     submissions = Submission.where(tutorial: self, assignment: assignment)
                             .proper.order(:last_modification_by_users_at)
@@ -37,11 +38,11 @@ def teams_to_csv(assignment)
       end
     end
   end
-  
+
   private
 
-  def check_destructibility
-  	throw(:abort) unless destructible?
-  	true
-  end
+    def check_destructibility
+      throw(:abort) unless destructible?
+      true
+    end
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index 58a29840f..0c4dec0a8 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -66,7 +66,8 @@ class User < ApplicationRecord
   # if a homepage is given it should at leat be a valid address
   validates :homepage, http_url: true, if: :homepage?
 
-  validates :locale, inclusion: { in: I18n.available_locales.map(&:to_s) }, if: :locale?
+  validates :locale, inclusion: { in: I18n.available_locales.map(&:to_s) },
+                     if: :locale?
 
   # a user needs to give a display name
   validates :name, presence: true, if: :persisted?
@@ -101,7 +102,6 @@ class User < ApplicationRecord
     text :tutorial_name
   end
 
-
   # returns the array of all teachers
   def self.teachers
     User.where(id: Lecture.pluck(:teacher_id).uniq)
@@ -137,6 +137,7 @@ def self.only_editors_selection
   # search params is a hash having keys :all_editors, :editor_ids
   def self.search_editors(search_params)
     return User.editors unless search_params[:all_editors] == '0'
+
     editor_ids = search_params[:editor_ids] || []
     User.where(id: editor_ids)
   end
@@ -145,7 +146,7 @@ def self.search_editors(search_params)
   # (e.g. in a select editors form)
   def self.select_editors
     User.pluck(:name, :email, :id, :name_in_tutorials)
-        .map { |u| [ "#{u.fourth.presence || u.first} (#{u.second})", u.third] }
+        .map { |u| ["#{u.fourth.presence || u.first} (#{u.second})", u.third] }
   end
 
   def self.name_or_email_like(search_string)
@@ -165,14 +166,17 @@ def self.preferred_name_or_email_like(search_string)
     return User.none unless search_string.length >= 2
 
     where(name_in_tutorials: [nil, '']).name_or_email_like(search_string)
-      .or(where.not(name_in_tutorials: [nil, ''])
+                                       .or(where.not(name_in_tutorials: [nil,
+                                                                         ''])
                .name_in_tutorials_or_email_like(search_string))
   end
 
   def self.values_for_select
     pluck(:id, :name, :name_in_tutorials, :email)
-      .map { |u| { value: u.first,
-                   text: "#{ u.third.presence || u.second } (#{u.fourth})" } }
+      .map { |u|
+      { value: u.first,
+        text: "#{u.third.presence || u.second} (#{u.fourth})" }
+    }
   end
 
   def courses
@@ -186,11 +190,13 @@ def courses
   # - all courses that the user has subscribed to (if subscription type is 3)
   def related_courses(overrule_subscription_type: false)
     return if subscription_type.nil?
+
     selection_type = overrule_subscription_type || subscription_type
     if selection_type == 1
       return Course.where(id: preceding_course_ids).includes(:lectures)
     end
     return Course.all.includes(:lectures) if selection_type == 2
+
     courses
   end
 
@@ -214,8 +220,10 @@ def related_lectures
   # returns ARel of all those tags from the given tags that belong to
   # the user's related lectures
   def filter_tags(tags)
-    Tag.where(id: tags.select { |t| t.in_lectures?(related_lectures) ||
-                                      t.in_courses?(related_courses) }
+    Tag.where(id: tags.select { |t|
+                    t.in_lectures?(related_lectures) ||
+                                      t.in_courses?(related_courses)
+                  }
                       .map(&:id))
   end
 
@@ -229,9 +237,9 @@ def filter_lectures(lectures)
   # the user's related lectures
   def filter_media(media)
     media.where(teachable: related_lectures)
-      .or(media.where(teachable: related_courses))
-      .or(media.where(teachable: Lesson.where(lecture: related_lectures)))
-      .or(media.where(teachable: Talk.where(lecture: related_lectures)))
+         .or(media.where(teachable: related_courses))
+         .or(media.where(teachable: Lesson.where(lecture: related_lectures)))
+         .or(media.where(teachable: Talk.where(lecture: related_lectures)))
   end
 
   # returns array of all those sections from the given sections that belon to
@@ -305,6 +313,7 @@ def editor?
 
   def info_uncached
     return email unless name.present?
+
     (name_in_tutorials.presence || name) + ' (' + email + ')'
   end
 
@@ -316,6 +325,7 @@ def info
 
   def tutorial_info_uncached
     return email unless tutorial_name.present?
+
     tutorial_name + ' (' + email + ')'
   end
 
@@ -327,6 +337,7 @@ def tutorial_info
 
   def name_or_email
     return name unless name.blank?
+
     email
   end
 
@@ -336,6 +347,7 @@ def tutorial_name
 
   def short_info
     return email unless name.present?
+
     name
   end
 
@@ -405,9 +417,10 @@ def unrelated_courses
   #    boards not belonging to lectures
   def thredded_can_read_messageboards
     return Thredded::Messageboard.all if admin?
+
     subscribed_forums =
       Thredded::Messageboard.where(id: lectures.map(&:forum_id))
-        .or(Thredded::Messageboard.where.not(id: Lecture.all.map(&:forum_id)))
+                            .or(Thredded::Messageboard.where.not(id: Lecture.all.map(&:forum_id)))
     if teacher? || edited_courses.any? || edited_lectures.any?
       return Thredded::Messageboard.where(id: teaching_related_lectures
                                                   .map(&:forum_id))
@@ -421,6 +434,7 @@ def thredded_can_read_messageboards
   #   lecture (they are for admins posts only)
   def thredded_can_write_messageboards
     return Thredded::Messageboard.all if admin?
+
     subscribed_forums =
       Thredded::Messageboard.where(id: lectures.map(&:forum_id))
     if teacher? || edited_courses.any? || edited_lectures.any?
@@ -438,6 +452,7 @@ def thredded_can_write_messageboards
   # - none otherwise
   def thredded_can_moderate_messageboards
     return Thredded::Messageboard.all if admin?
+
     if teacher? || edited_courses.any? || edited_lectures.any?
       return Thredded::Messageboard.where(id: teaching_related_lectures
                                                 .map(&:forum_id))
@@ -464,25 +479,26 @@ def filter_visible_media(media)
     nonsubscribed_talks = Talk.where(lecture: nonsubscribed_lectures)
     edited_talks = Talk.where(lecture: teaching_related_lectures)
     return media if admin
+
     media.where(teachable: courses, released: ['all', 'subscribers', 'users'])
-      .or(media.where(teachable: nonsubscribed_courses,
-                      released: ['all', 'users']))
-      .or(media.where(teachable: lectures,
-                      released: ['all', 'subscribers', 'users']))
-      .or(media.where(teachable: nonsubscribed_lectures,
-                      released: ['all', 'users']))
-      .or(media.where(teachable: lessons,
-                      released: ['all', 'subscribers', 'users']))
-      .or(media.where(teachable: nonsubscribed_lessons,
-                      released: ['all', 'users']))
-      .or(media.where(teachable: talks,
-                      released: ['all', 'subscribers', 'users']))
-      .or(media.where(teachable: nonsubscribed_talks,
-                      released: ['all', 'users']))
-      .or(media.where(teachable: edited_courses))
-      .or(media.where(teachable: teaching_related_lectures))
-      .or(media.where(teachable: edited_lessons))
-      .or(media.where(teachable: edited_talks))
+         .or(media.where(teachable: nonsubscribed_courses,
+                         released: ['all', 'users']))
+         .or(media.where(teachable: lectures,
+                         released: ['all', 'subscribers', 'users']))
+         .or(media.where(teachable: nonsubscribed_lectures,
+                         released: ['all', 'users']))
+         .or(media.where(teachable: lessons,
+                         released: ['all', 'subscribers', 'users']))
+         .or(media.where(teachable: nonsubscribed_lessons,
+                         released: ['all', 'users']))
+         .or(media.where(teachable: talks,
+                         released: ['all', 'subscribers', 'users']))
+         .or(media.where(teachable: nonsubscribed_talks,
+                         released: ['all', 'users']))
+         .or(media.where(teachable: edited_courses))
+         .or(media.where(teachable: teaching_related_lectures))
+         .or(media.where(teachable: edited_lessons))
+         .or(media.where(teachable: edited_talks))
   end
 
   def subscribed_commentable_media_with_comments
@@ -496,11 +512,13 @@ def subscribed_commentable_media_with_comments
 
   def media_latest_comments
     subscribed_commentable_media_with_comments
-      .map { |m| { medium: m,
-                   thread: m.commontator_thread,
-                   latest_comment: m.commontator_thread
-                                    .comments.sort_by(&:created_at)
-                                    .last } }
+      .map { |m|
+      { medium: m,
+        thread: m.commontator_thread,
+        latest_comment: m.commontator_thread
+                         .comments.sort_by(&:created_at)
+                         .last }
+    }
       .sort_by { |x| x[:latest_comment].created_at }.reverse
   end
 
@@ -524,8 +542,9 @@ def anonymized_id
   def subscribe_lecture!(lecture)
     return false unless lecture.is_a?(Lecture)
     return false if lecture.in?(lectures)
+
     lectures << lecture
-    
+
     # make sure subscribed_users is updated in media
     Sunspot.index! lecture.media
 
@@ -535,6 +554,7 @@ def subscribe_lecture!(lecture)
   def unsubscribe_lecture!(lecture)
     return false unless lecture.is_a?(Lecture)
     return false unless lecture.in?(lectures)
+
     lectures.delete(lecture)
     favorite_lectures.delete(lecture)
 
@@ -555,6 +575,7 @@ def current_subscribable_lectures
     unless editor? || teacher?
       return current_lectures.published.sort + no_term_lectures.published.sort
     end
+
     current_lectures.select { |l| l.edited_by?(self) || l.published? }.sort +
       no_term_lectures.select { |l| l.edited_by?(self) || l.published? }.sort
   end
@@ -667,6 +688,7 @@ def can_edit?(something)
       raise 'can_edit? was called with incompatible class'
     end
     return true if admin
+
     in?(something.editors_with_inheritance.to_a)
   end
 
@@ -676,6 +698,7 @@ def speaker?
 
   def layout
     return 'administration' if admin_or_editor?
+
     'application_no_sidebar'
   end
 
@@ -693,48 +716,49 @@ def generic?
 
   private
 
-  def set_defaults
-    self.subscription_type ||= 1
-    self.admin ||= false
-    self.name ||= email.split('@').first
-    self.locale ||= I18n.default_locale.to_s
-  end
+    def set_defaults
+      self.subscription_type ||= 1
+      self.admin ||= false
+      self.name ||= email.split('@').first
+      self.locale ||= I18n.default_locale.to_s
+    end
 
-  # sets time for DSGVO consent to current time
-  def set_consented_at
-    update(consented_at: Time.now)
-  end
+    # sets time for DSGVO consent to current time
+    def set_consented_at
+      update(consented_at: Time.now)
+    end
 
-  # returns array of ids of all courses that preced the subscribed courses
-  def preceding_course_ids
-    courses.all.map { |l| l.preceding_courses.pluck(:id) }.flatten +
-      courses.all.pluck(:id)
-  end
+    # returns array of ids of all courses that preced the subscribed courses
+    def preceding_course_ids
+      courses.all.map { |l| l.preceding_courses.pluck(:id) }.flatten +
+        courses.all.pluck(:id)
+    end
 
-  def destroy_single_submissions
-    Submission.where(id: submissions.select { |s| s.users.count == 1 }
-                                    .map(&:id)).destroy_all
-  end
+    def destroy_single_submissions
+      Submission.where(id: submissions.select { |s| s.users.count == 1 }
+                                      .map(&:id)).destroy_all
+    end
 
-  def archive_email
-    splitting = DefaultSetting::PROJECT_EMAIL.split('@')
-    "#{splitting.first}-archive-#{id}@#{splitting.second}"
-  end
+    def archive_email
+      splitting = DefaultSetting::PROJECT_EMAIL.split('@')
+      "#{splitting.first}-archive-#{id}@#{splitting.second}"
+    end
 
-  def transfer_contributions_to(user)
-    return false unless user && user.valid? && user != self
-    given_lectures.update_all(teacher_id: user.id)
-    EditableUserJoin.where(user: self, editable_type: 'Medium')
-                    .update_all(user_id: user.id)
-  end
+    def transfer_contributions_to(user)
+      return false unless user && user.valid? && user != self
 
-  def archive_user(archive_name)
-    User.create(name: archive_name,
-                email: archive_email,
-                password: SecureRandom.base58(12),
-                consents: true,
-                consented_at: Time.now,
-                confirmed_at: Time.now,
-                archived: true)
-  end
+      given_lectures.update_all(teacher_id: user.id)
+      EditableUserJoin.where(user: self, editable_type: 'Medium')
+                      .update_all(user_id: user.id)
+    end
+
+    def archive_user(archive_name)
+      User.create(name: archive_name,
+                  email: archive_email,
+                  password: SecureRandom.base58(12),
+                  consents: true,
+                  consented_at: Time.now,
+                  confirmed_at: Time.now,
+                  archived: true)
+    end
 end
diff --git a/app/models/user_cleaner.rb b/app/models/user_cleaner.rb
index 02a58466b..9c40eecba 100644
--- a/app/models/user_cleaner.rb
+++ b/app/models/user_cleaner.rb
@@ -4,7 +4,8 @@ class UserCleaner
 
   def login
     @imap = Net::IMAP.new(ENV['IMAPSERVER'], port: 993, ssl: true)
-    @imap.authenticate('LOGIN', ENV['PROJECT_EMAIL_USERNAME'], ENV['PROJECT_EMAIL_PASSWORD'])
+    @imap.authenticate('LOGIN', ENV['PROJECT_EMAIL_USERNAME'],
+                       ENV['PROJECT_EMAIL_PASSWORD'])
   end
 
   def logout
@@ -16,8 +17,10 @@ def search_emails_and_hashes
     @hash_dict = {}
     @imap.examine(ENV['PROJECT_EMAIL_MAILBOX'])
     # Mails containing multiple email addresses (Subject: "Undelivered Mail Returned to Sender")
-    @imap.search(['SUBJECT', 'Undelivered Mail Returned to Sender']).each do |message_id|
-      body = @imap.fetch(message_id, "BODY[TEXT]")[0].attr["BODY[TEXT]"].squeeze(" ")
+    @imap.search(['SUBJECT',
+                  'Undelivered Mail Returned to Sender']).each do |message_id|
+      body = @imap.fetch(message_id,
+                         "BODY[TEXT]")[0].attr["BODY[TEXT]"].squeeze(" ")
       if match = body.scan(/([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4})[\s\S]*?([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4})[\s\S]*?User has moved to ERROR: Account expired/)
         match = match.flatten.uniq
         match.each do |email|
@@ -34,8 +37,10 @@ def search_emails_and_hashes
       '([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4})>[\s\S]*?User unknown in virtual mailbox table'
     ]
 
-    @imap.search(['SUBJECT', 'Delivery Status Notification (Failure)']).each do |message_id|
-      body = @imap.fetch(message_id, "BODY[TEXT]")[0].attr["BODY[TEXT]"].squeeze(" ")
+    @imap.search(['SUBJECT',
+                  'Delivery Status Notification (Failure)']).each do |message_id|
+      body = @imap.fetch(message_id,
+                         "BODY[TEXT]")[0].attr["BODY[TEXT]"].squeeze(" ")
       patterns.each do |pattern|
         if match = body.scan(/#{pattern}/)
           match = match.flatten.uniq
@@ -87,10 +92,11 @@ def delete_ghosts
     end
   end
 
-  def move_mail(message_ids, attempt=0)
+  def move_mail(message_ids, attempt = 0)
     return if message_ids.blank?
+
     message_ids = Array(message_ids)
-    if attempt>3
+    if attempt > 3
       return
     end
 
@@ -98,7 +104,7 @@ def move_mail(message_ids, attempt=0)
       @imap.examine(ENV['PROJECT_EMAIL_MAILBOX'])
       @imap.move(message_ids, "Other Users/mampf/handled_bounces")
     rescue Net::IMAP::BadResponseError
-      move_mail(message_ids, attempt=attempt+1)
+      move_mail(message_ids, attempt = attempt + 1)
     end
   end
 
@@ -106,11 +112,11 @@ def clean!
     login
     search_emails_and_hashes
     return if @email_dict.blank?
+
     send_hashes
     sleep(10)
     search_emails_and_hashes
     delete_ghosts
     logout
   end
-
-end
\ No newline at end of file
+end
diff --git a/app/models/user_submission_join.rb b/app/models/user_submission_join.rb
index d0c6b6d01..9218519c6 100644
--- a/app/models/user_submission_join.rb
+++ b/app/models/user_submission_join.rb
@@ -6,23 +6,26 @@ class UserSubmissionJoin < ApplicationRecord
   validate :max_team_size, on: :create
 
   def assignment
-  	submission.assignment
+    submission.assignment
   end
 
   private
 
-  def only_one_per_assignment
-  	if UserSubmissionJoin.where(user: user, submission: assignment.submissions)
-	   										 .none?
-	   	return true
-	  end
-  	errors.add(:base, :only_one_per_assignment)
-  end
+    def only_one_per_assignment
+      if UserSubmissionJoin.where(user: user,
+                                  submission: assignment.submissions)
+                           .none?
+        return true
+      end
 
-  def max_team_size
-  	lecture = submission.assignment.lecture
-  	return true unless lecture.submission_max_team_size
-  	return true if submission.users.size < lecture.submission_max_team_size
-  	errors.add(:base, :team_size)
-  end
+      errors.add(:base, :only_one_per_assignment)
+    end
+
+    def max_team_size
+      lecture = submission.assignment.lecture
+      return true unless lecture.submission_max_team_size
+      return true if submission.users.size < lecture.submission_max_team_size
+
+      errors.add(:base, :team_size)
+    end
 end
diff --git a/app/uploaders/correction_uploader.rb b/app/uploaders/correction_uploader.rb
index a17390266..cc7a30ba3 100644
--- a/app/uploaders/correction_uploader.rb
+++ b/app/uploaders/correction_uploader.rb
@@ -4,6 +4,6 @@
 class CorrectionUploader < Shrine
   # shrine plugins
   plugin :determine_mime_type, analyzer: :marcel
-  plugin :upload_endpoint, max_size: 30*1024*1024 # 30 MB
+  plugin :upload_endpoint, max_size: 30 * 1024 * 1024 # 30 MB
   plugin :default_storage, cache: :submission_cache, store: :submission_store
 end
diff --git a/app/uploaders/geogebra_uploader.rb b/app/uploaders/geogebra_uploader.rb
index 5e11e9977..32fe00ff5 100644
--- a/app/uploaders/geogebra_uploader.rb
+++ b/app/uploaders/geogebra_uploader.rb
@@ -24,4 +24,4 @@ class GeogebraUploader < Shrine
     end
     { screenshot: File.open(unzipped) }
   end
-end
\ No newline at end of file
+end
diff --git a/app/uploaders/pdf_uploader.rb b/app/uploaders/pdf_uploader.rb
index d75b6add2..bacdb9bcc 100644
--- a/app/uploaders/pdf_uploader.rb
+++ b/app/uploaders/pdf_uploader.rb
@@ -30,14 +30,14 @@ class PdfUploader < Shrine
           # extract lines that correspond to MaMpf-Label entries from LaTEX
           # package mampf.sty
           structure = if File.file?(structure_path)
-                        open(structure_path, "r") do
-                          |io| io.read.encode("UTF-8", invalid: :replace)
-                        end
-                      end
+            open(structure_path, "r") do |io|
+              io.read.encode("UTF-8", invalid: :replace)
+            end
+          end
           structure ||= ''
           bookmarks = structure.scan(/MaMpf-Label\|(.*?)\n/).flatten
           result = []
-          bookmarks.each_with_index do |b,i|
+          bookmarks.each_with_index do |b, i|
             # extract bookmark data
             # line may look like this:
             # defn:erster-Tag|Definition|1.1|Erster Tag|1
diff --git a/app/uploaders/submission_uploader.rb b/app/uploaders/submission_uploader.rb
index 243402594..dd8d4f9e5 100644
--- a/app/uploaders/submission_uploader.rb
+++ b/app/uploaders/submission_uploader.rb
@@ -4,7 +4,7 @@
 class SubmissionUploader < Shrine
   # shrine plugins
   plugin :determine_mime_type, analyzer: :marcel
-  plugin :upload_endpoint, max_size: 20*1024*1024 # 20 MB
-	plugin :default_storage, cache: :submission_cache, store: :submission_store
-	plugin :restore_cached_data
+  plugin :upload_endpoint, max_size: 20 * 1024 * 1024 # 20 MB
+  plugin :default_storage, cache: :submission_cache, store: :submission_store
+  plugin :restore_cached_data
 end
diff --git a/app/uploaders/video_uploader.rb b/app/uploaders/video_uploader.rb
index 3613a50fb..4e42b3134 100644
--- a/app/uploaders/video_uploader.rb
+++ b/app/uploaders/video_uploader.rb
@@ -16,8 +16,8 @@ class VideoUploader < Shrine
     if options[:action] != :upload
       movie = Shrine.with_file(io) { |file| FFMPEG::Movie.new(file.path) }
 
-      { 'duration'   => movie.duration,
-        'bitrate'    => movie.bitrate,
+      { 'duration' => movie.duration,
+        'bitrate' => movie.bitrate,
         'resolution' => movie.resolution,
         'frame_rate' => movie.frame_rate }
     end
diff --git a/app/uploaders/vtt_uploader.rb b/app/uploaders/vtt_uploader.rb
index d6cc77163..0e8dfdcce 100644
--- a/app/uploaders/vtt_uploader.rb
+++ b/app/uploaders/vtt_uploader.rb
@@ -2,4 +2,4 @@
 class VttUploader < Shrine
   plugin :pretty_location
   plugin :determine_mime_type
-end
\ No newline at end of file
+end
diff --git a/app/uploaders/zip_uploader.rb b/app/uploaders/zip_uploader.rb
index f2ce1220d..353280167 100644
--- a/app/uploaders/zip_uploader.rb
+++ b/app/uploaders/zip_uploader.rb
@@ -3,15 +3,15 @@ class ZipUploader < Shrine
   # shrine plugins
   plugin :determine_mime_type, analyzer: :marcel
   plugin :validation_helpers
-  plugin :upload_endpoint, max_size: 1024*1024*1024 #  1 GB
-	plugin :default_storage, cache: :submission_cache, store: :submission_store
+  plugin :upload_endpoint, max_size: 1024 * 1024 * 1024 #  1 GB
+  plugin :default_storage, cache: :submission_cache, store: :submission_store
 
   Attacher.validate do
     validate_mime_type_inclusion %w[application/zip],
-    														 message:
-    														 	 I18n.t('package.no_zip')
-		# maximum size of 1 GB
-    validate_max_size 1024*1024*1024,
-    									message: I18n.t('package.too_big')
+                                 message:
+                                    I18n.t('package.no_zip')
+    # maximum size of 1 GB
+    validate_max_size 1024 * 1024 * 1024,
+                      message: I18n.t('package.too_big')
   end
-end
\ No newline at end of file
+end
diff --git a/app/validators/http_url_validator.rb b/app/validators/http_url_validator.rb
index 68806ee14..7dcf6ac83 100644
--- a/app/validators/http_url_validator.rb
+++ b/app/validators/http_url_validator.rb
@@ -1,5 +1,4 @@
 class HttpUrlValidator < ActiveModel::EachValidator
-
   def self.compliant?(value)
     uri = URI.parse(Addressable::URI.encode(value))
     uri.is_a?(URI::HTTP) && !uri.host.nil?
diff --git a/app/views/users/list.json.jbuilder b/app/views/users/list.json.jbuilder
index 87cfb45e1..c6df8a8ba 100644
--- a/app/views/users/list.json.jbuilder
+++ b/app/views/users/list.json.jbuilder
@@ -1,4 +1,4 @@
 json.array! @users do |user|
   json.id user.id
   json.text user.tutorial_info
-end
\ No newline at end of file
+end
diff --git a/app/workers/cache_cleaner.rb b/app/workers/cache_cleaner.rb
index 566ddfd47..6b77f4bf4 100644
--- a/app/workers/cache_cleaner.rb
+++ b/app/workers/cache_cleaner.rb
@@ -7,4 +7,4 @@ def perform
     submission_cache.clear! { |path| path.mtime < Time.now - 1.week }
     media_cache.clear! { |path| path.mtime < Time.now - 1.week }
   end
-end
\ No newline at end of file
+end
diff --git a/app/workers/consumption_saver.rb b/app/workers/consumption_saver.rb
index ca1d9add6..924772b77 100644
--- a/app/workers/consumption_saver.rb
+++ b/app/workers/consumption_saver.rb
@@ -6,4 +6,4 @@ def perform(medium_id, mode, sort)
                        mode: mode,
                        sort: sort)
   end
-end
\ No newline at end of file
+end
diff --git a/app/workers/interaction_saver.rb b/app/workers/interaction_saver.rb
index 05fa6b36f..ec89207ad 100644
--- a/app/workers/interaction_saver.rb
+++ b/app/workers/interaction_saver.rb
@@ -3,12 +3,12 @@ class InteractionSaver
 
   def perform(session_id, full_path, referrer, study_participant)
     referrer_url = if referrer.to_s.include?(ENV['URL_HOST'])
-                     referrer.to_s.remove(ENV['URL_HOST'])
-                                  .remove('https://').remove('http://')
-                   end
+      referrer.to_s.remove(ENV['URL_HOST'])
+              .remove('https://').remove('http://')
+    end
     Interaction.create(session_id: Digest::SHA2.hexdigest(session_id).first(10),
                        full_path: full_path,
                        referrer_url: referrer_url,
                        study_participant: study_participant)
   end
-end
\ No newline at end of file
+end
diff --git a/app/workers/media_publisher.rb b/app/workers/media_publisher.rb
index e847da8b3..17318e427 100644
--- a/app/workers/media_publisher.rb
+++ b/app/workers/media_publisher.rb
@@ -7,4 +7,4 @@ def perform
                       .map(&:medium_id)
     Medium.where(id: media_ids).each(&:publish!)
   end
-end
\ No newline at end of file
+end
diff --git a/app/workers/metadata_extractor.rb b/app/workers/metadata_extractor.rb
index 428ecfb9f..08384735b 100644
--- a/app/workers/metadata_extractor.rb
+++ b/app/workers/metadata_extractor.rb
@@ -4,8 +4,9 @@ class MetadataExtractor
   def perform(medium_id)
     medium = Medium.find(medium_id)
     return unless medium && medium.video.present?
+
     medium.video.refresh_metadata!(action: :store)
     refreshed_video = medium.video
     medium.update(video_data: refreshed_video.to_json)
   end
-end
\ No newline at end of file
+end
diff --git a/app/workers/probe_saver.rb b/app/workers/probe_saver.rb
index 83a86c09c..553f5399e 100644
--- a/app/workers/probe_saver.rb
+++ b/app/workers/probe_saver.rb
@@ -12,7 +12,8 @@ def perform(quiz_id, question_id, remark_id, correct, progress, session_id,
                          study_participant: study_participant,
                          input: input)
     return unless progress == -1
+
     success = Probe.where(session_id: session_id, correct: true).count
     probe.update(success: success)
   end
-end
\ No newline at end of file
+end
diff --git a/app/workers/submissions_cleaner.rb b/app/workers/submissions_cleaner.rb
index e5660eb1f..14bebf6ed 100644
--- a/app/workers/submissions_cleaner.rb
+++ b/app/workers/submissions_cleaner.rb
@@ -5,4 +5,4 @@ def perform
     submission_cleaner = SubmissionCleaner.new(date: Time.zone.today)
     submission_cleaner.clean!
   end
-end
\ No newline at end of file
+end
diff --git a/app/workers/user_cleaner_job.rb b/app/workers/user_cleaner_job.rb
index d64a651bf..4c0187a89 100644
--- a/app/workers/user_cleaner_job.rb
+++ b/app/workers/user_cleaner_job.rb
@@ -5,4 +5,4 @@ def perform
     user_cleaner = UserCleaner.new()
     user_cleaner.clean!
   end
-end
\ No newline at end of file
+end

From 1982f2875184823f1657cf53a74615b0ab2973ff Mon Sep 17 00:00:00 2001
From: Splines <37160523+Splines@users.noreply.github.com>
Date: Thu, 11 May 2023 18:45:32 +0200
Subject: [PATCH 13/22] Fix scope of .new-comment CSS class (#499)

---
 app/assets/stylesheets/navbar.scss | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/app/assets/stylesheets/navbar.scss b/app/assets/stylesheets/navbar.scss
index 282060bcf..18bd50825 100644
--- a/app/assets/stylesheets/navbar.scss
+++ b/app/assets/stylesheets/navbar.scss
@@ -19,6 +19,10 @@
 .navbar {
     box-shadow: 1px 4px 7px -2px rgba(0, 0, 0, 0.1);
     z-index: 1000; // place navbar and its shadow on top of everything
+
+    .new-comment {
+        color: #ffc107 !important;
+    }
 }
 
 #navbar-buttons a {
@@ -36,8 +40,4 @@
             left: 16px;
         }
     }
-}
-
-.new-comment {
-    color: #ffc107 !important;
 }
\ No newline at end of file

From 3fc077fb973bc5cce0e66f4264e0db761a4019be Mon Sep 17 00:00:00 2001
From: Splines <37160523+Splines@users.noreply.github.com>
Date: Mon, 15 May 2023 14:59:32 +0200
Subject: [PATCH 14/22] Fix ghost links in nested tabs (#500)

* Fix ghost links in nested tabs

* Fix spacing in media card
---
 app/assets/stylesheets/media.scss       |  15 ----
 app/views/lectures/edit/_media.html.erb |   8 +-
 app/views/media/_table_column.html.erb  | 113 ++++++++++++------------
 3 files changed, 62 insertions(+), 74 deletions(-)

diff --git a/app/assets/stylesheets/media.scss b/app/assets/stylesheets/media.scss
index 97d707e52..938a0ec7e 100644
--- a/app/assets/stylesheets/media.scss
+++ b/app/assets/stylesheets/media.scss
@@ -315,21 +315,6 @@
   text-decoration: none;
 }
 
-.tab-content {
-  display: flex;
-}
-
-.tab-content > .tab-pane {
-  display: block; /* undo "display: none;" */
-  visibility: hidden;
-  margin-right: -100%;
-  width: 100%;
-}
-
-.tab-content > .active {
-  visibility: visible;
-}
-
 .break-text-any-where {
   word-break: break-all;
 }
\ No newline at end of file
diff --git a/app/views/lectures/edit/_media.html.erb b/app/views/lectures/edit/_media.html.erb
index 8f2ec846f..2d2bedf47 100644
--- a/app/views/lectures/edit/_media.html.erb
+++ b/app/views/lectures/edit/_media.html.erb
@@ -29,12 +29,12 @@
   </div>
   <div class="card-body">
     <div class="row">
-      <div class="col-4">
+      <div class="col-5">
         <ul class="nav flex-column nav-pills"
             id="edited-media-tab"
             role="tablist">
           <% media_sorts.each do |s| %>
-            <li class="nav-item">
+            <li class="nav-item w-100">
               <a class="nav-link <%= active(s == 'kaviar') %>"
                  id="<%= s %>-tab"
                  data-toggle="tab" href="#<%= s %>-media" role="tab"
@@ -47,14 +47,14 @@
           <% end %>
         </ul>
       </div>
-      <div class="col-8">
+      <div class="col-7">
         <div class="tab-content" id="edited-media-tabContent">
           <% media_sorts.each do |s| %>
             <div class="tab-pane fade <%= show_tab(s == 'kaviar') %>"
                  id="<%= s %>-media"
                  role="tabpanel"
                  aria-labelledby="<%= s %>-tab">
-              <ul>
+              <ul class="pl-2">
                 <% media.select { |m| m.sort.in?(media_types[s]) }
                         .sort_by(&:created_at)
                         .reverse
diff --git a/app/views/media/_table_column.html.erb b/app/views/media/_table_column.html.erb
index 6ab9e1dc9..d782dad20 100644
--- a/app/views/media/_table_column.html.erb
+++ b/app/views/media/_table_column.html.erb
@@ -1,63 +1,66 @@
 <% if media.present? %>
   <% if small %>
-    <ul>
-      <% media.each do |m| %>
-        <li>
-          <%= link_to m.local_info,
-                      edit_or_inspect_medium_path(m),
-                      class: textcolor(m) %>
-        </li>
-      <% end %>
-    </ul>
+    <div class="tab-content">
+      <ul>
+        <% media.each do |m| %>
+          <li>
+            <%= link_to m.local_info,
+                        edit_or_inspect_medium_path(m),
+                        class: textcolor(m) %>
+          </li>
+        <% end %>
+      </ul>
+    </div>
   <% else %>
     <% teachables = lecture_course_teachables(media) %>
-    <div class="row">
-      <div class="col-3">
-        <div class="nav flex-column nav-tabs"
-             id="v-<%= sort %>-media-tab"
-             role="tablist"
-             aria-orientation="vertical">
-          <% teachables.each_with_index do |t, i| %>
-            <a class="nav-link <%= active(i.zero?) %>"
-               id="v-pills-<%= sort %>-<%= t.class %>-<%= t.id %>-tab"
-               data-toggle="pill"
-               href="#v-pills-<%= sort %>-<%= t.class %>-<%= t.id %>"
-               role="tab">
-              <%= t.short_title %>
-            </a>
-          <% end %>
+    <div class="tab-content">
+      <div class="row">
+        <div class="col-3">
+          <div class="nav flex-column nav-tabs"
+              id="v-<%= sort %>-media-tab"
+              role="tablist"
+              aria-orientation="vertical">
+            <% teachables.each_with_index do |t, i| %>
+              <a class="nav-link <%= active(i.zero?) %>"
+                id="v-pills-<%= sort %>-<%= t.class %>-<%= t.id %>-tab"
+                data-toggle="pill"
+                href="#v-pills-<%= sort %>-<%= t.class %>-<%= t.id %>"
+                role="tab">
+                <%= t.short_title %>
+              </a>
+            <% end %>
+          </div>
         </div>
-      </div>
-      <div class="col-9">
-        <div class="tab-content"
-             id="v-<%= sort %>-media-tabContent">
-          <% teachables.each_with_index do |t, i| %>
-            <div class="tab-pane fade <%= show_tab(i == 0) %>"
-                 id="v-pills-<%= sort %>-<%= t.class %>-<%= t.id %>"
-                 role="tabpanel">
-              <% relevant = relevant_media(t, media, 50)&.sort_by(&:created_at)
-                                                        &.natural_sort_by(&:local_info) %>
-              <% if relevant.present? %>
-                <div class="row">
-                  <% split_list(relevant, 2).each do |media_list| %>
-                    <div class="col-6">
-                      <ul>
-                        <%= render partial: 'media/table/entry',
-                                   collection: media_list.compact,
-                                   as: :medium,
-                                   cached: true %>
-                      </ul>
-                    </div>
-                  <% end %>
-                </div>
-              <% end %>
-              <% if relevant.size == 50 %>
-                <%= t('admin.medium.use_search_html',
-                      media_search: link_to(t('admin.main.media_search'),
-                                            administration_search_path)) %>
-              <% end %>
-            </div>
-          <% end %>
+        <div class="col-9">
+          <div class="tab-content" id="v-<%= sort %>-media-tabContent">
+            <% teachables.each_with_index do |t, i| %>
+              <div class="tab-pane fade <%= show_tab(i == 0) %>"
+                  id="v-pills-<%= sort %>-<%= t.class %>-<%= t.id %>"
+                  role="tabpanel">
+                <% relevant = relevant_media(t, media, 50)&.sort_by(&:created_at)
+                                                          &.natural_sort_by(&:local_info) %>
+                <% if relevant.present? %>
+                  <div class="row">
+                    <% split_list(relevant, 2).each do |media_list| %>
+                      <div class="col-6">
+                        <ul>
+                          <%= render partial: 'media/table/entry',
+                                    collection: media_list.compact,
+                                    as: :medium,
+                                    cached: true %>
+                        </ul>
+                      </div>
+                    <% end %>
+                  </div>
+                <% end %>
+                <% if relevant.size == 50 %>
+                  <%= t('admin.medium.use_search_html',
+                        media_search: link_to(t('admin.main.media_search'),
+                                              administration_search_path)) %>
+                <% end %>
+              </div>
+            <% end %>
+          </div>
         </div>
       </div>
     </div>

From 38a48127ef33ca06b4485664c5053a7eb4f9f654 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Mon, 15 May 2023 16:50:02 +0200
Subject: [PATCH 15/22] refactor user controller and views

---
 app/controllers/users_controller.rb     | 2 +-
 app/views/users/_generic_users.html.erb | 2 +-
 app/views/users/_modal.html.erb         | 2 +-
 app/views/users/index.html.erb          | 4 ++--
 app/views/users/list.json.jbuilder      | 4 ----
 5 files changed, 5 insertions(+), 9 deletions(-)
 delete mode 100644 app/views/users/list.json.jbuilder

diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 0ed0ae4c2..b5873fe28 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -11,7 +11,7 @@ def current_ability
 
   def index
     authorize! :index, User.new
-    @generic_users = User.where.not(id: @elevated_users.pluck(:id))
+    @generic_users_count = User.where.not(id: @elevated_users.pluck(:id)).count
   end
 
   def edit
diff --git a/app/views/users/_generic_users.html.erb b/app/views/users/_generic_users.html.erb
index 850418c03..46ea536b0 100644
--- a/app/views/users/_generic_users.html.erb
+++ b/app/views/users/_generic_users.html.erb
@@ -1,5 +1,5 @@
 <div id="user-search-form">
-  <% if generic_users.present? %>
+  <% if generic_users_count.positive? %>
     <%= form_with url: elevate_user_path,
                   scope: 'generic_user',
                   method: 'get' do |f| %>
diff --git a/app/views/users/_modal.html.erb b/app/views/users/_modal.html.erb
index 861204137..6a0a7b7d3 100644
--- a/app/views/users/_modal.html.erb
+++ b/app/views/users/_modal.html.erb
@@ -23,7 +23,7 @@
       <div class="modal-body"
            id="generic-users-modal-content">
         <%= render partial: "users/generic_users",
-                   locals: { generic_users: generic_users } %>
+                   locals: { generic_users_count: generic_users_count } %>
       </div>
       <div class="modal-footer">
         <div class="row">
diff --git a/app/views/users/index.html.erb b/app/views/users/index.html.erb
index f54b62266..f517b62bd 100644
--- a/app/views/users/index.html.erb
+++ b/app/views/users/index.html.erb
@@ -9,8 +9,8 @@
   <div class="col-12">
     <%= render partial: 'users/elevated_users',
                locals: { elevated_users: @elevated_users,
-                         generic_users_count: @generic_users.count } %>
+                         generic_users_count: @generic_users_count } %>
   </div>
 </div>
 <%= render partial: 'users/modal',
-           locals: { generic_users: @generic_users } %>
+           locals: { generic_users_count: @generic_users_count } %>
diff --git a/app/views/users/list.json.jbuilder b/app/views/users/list.json.jbuilder
deleted file mode 100644
index c6df8a8ba..000000000
--- a/app/views/users/list.json.jbuilder
+++ /dev/null
@@ -1,4 +0,0 @@
-json.array! @users do |user|
-  json.id user.id
-  json.text user.tutorial_info
-end

From eb7e7b46c0eaa2153ebbcf48e623e4712c010782 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Mon, 15 May 2023 17:40:26 +0200
Subject: [PATCH 16/22] restore previous behaviour of media search

---
 app/controllers/media_controller.rb           |  2 +-
 app/helpers/media_helper.rb                   |  2 +-
 app/models/medium.rb                          | 18 ++++++++++----
 app/views/main/start/_media_search.html.erb   |  3 ++-
 app/views/media/catalog/_search_form.html.erb | 24 +++++++++++--------
 5 files changed, 32 insertions(+), 17 deletions(-)

diff --git a/app/controllers/media_controller.rb b/app/controllers/media_controller.rb
index 183c351dc..1c9633596 100644
--- a/app/controllers/media_controller.rb
+++ b/app/controllers/media_controller.rb
@@ -680,7 +680,7 @@ def search_params
                     :teachable_inheritance, :fulltext, :per,
                     :clicker, :purpose, :answers_count,
                     :results_as_list, :all_terms, :all_teachers,
-                    :lecture_option, :user_id,
+                    :lecture_option, :user_id, :from,
                     types: [],
                     teachable_ids: [],
                     tag_ids: [],
diff --git a/app/helpers/media_helper.rb b/app/helpers/media_helper.rb
index a95385e85..cfd036ebc 100644
--- a/app/helpers/media_helper.rb
+++ b/app/helpers/media_helper.rb
@@ -109,7 +109,7 @@ def media_sorts_select(purpose)
     return add_prompt(Medium.select_quizzables) if purpose == 'quiz'
     return Medium.select_question if purpose == 'clicker'
     return add_prompt(Medium.select_importables) if purpose == 'import'
-    return add_prompt(Medium.select_generic) if !current_user.admin?
+    return add_prompt(Medium.select_generic) if !current_user.admin_or_editor?
 
     add_prompt(Medium.select_sorts)
   end
diff --git a/app/models/medium.rb b/app/models/medium.rb
index c851d537e..f3a8f8eb6 100644
--- a/app/models/medium.rb
+++ b/app/models/medium.rb
@@ -202,7 +202,7 @@ def self.select_sorts
   end
 
   def self.advanced_sorts
-    ['RandomQuiz', 'Question', 'Remark', 'Erdbeere']
+    ['Question', 'Remark', 'Erdbeere']
   end
 
   def self.generic_sorts
@@ -282,7 +282,16 @@ def self.lecture_search_option
   # returns search results for the media search with search_params provided
   # by the controller
   def self.search_by(search_params, page)
-    search_params[:types] = [] if search_params[:all_types] == '1'
+    # If the search is initiated from the start page, you can only get
+    # generic media sorts as results even if the 'all' radio button
+    # is seleted
+    if search_params[:all_types] == '1'
+      search_params[:types] = if search_params[:from] == 'start'
+                                Medium.generic_sorts
+                              else
+                                []
+                              end
+    end
     search_params[:teachable_ids] = TeachableParser.new(search_params)
                                                    .teachables_as_strings
     search_params[:editor_ids] =
@@ -295,11 +304,12 @@ def self.search_by(search_params, page)
     if search_params[:all_tags] == '1' && search_params[:tag_operator] == 'and'
       search_params[:tag_ids] = Tag.pluck(:id)
     end
-    admin = User.find_by(id: search_params[:user_id])&.admin?
+    user = User.find_by(id: search_params[:user_id])
     search = Sunspot.new_search(Medium)
     search.build do
       with(:sort, search_params[:types])
-      without(:sort, Medium.advanced_sorts) unless admin
+      without(:sort, 'RandomQuiz')
+      without(:sort, Medium.advanced_sorts) unless user&.admin_or_editor?
       with(:editor_ids, search_params[:editor_ids])
       with(:teachable_compact, search_params[:teachable_ids])
       with(:term_id,
diff --git a/app/views/main/start/_media_search.html.erb b/app/views/main/start/_media_search.html.erb
index 08fde22bb..d57e8da70 100644
--- a/app/views/main/start/_media_search.html.erb
+++ b/app/views/main/start/_media_search.html.erb
@@ -125,7 +125,7 @@
                             '2',
                             checked: false,
                             class: 'custom-control-input',
-                            data: { type: 'toggle', 
+                            data: { type: 'toggle',
                                     id: 'search_media_lectures'} %>
         <%= f.label :lecture_option,
                     t('search.media.lecture_options.own_selection'),
@@ -162,6 +162,7 @@
   <%= f.hidden_field :purpose, value: purpose %>
   <%= f.hidden_field :results_as_list,
                      value: 'false' %>
+  <%= f.hidden_field :from, value: 'start' %>
   <div class="row mb-3">
     <div class="col-12 text-center">
       <%= f.submit t('basics.search'),
diff --git a/app/views/media/catalog/_search_form.html.erb b/app/views/media/catalog/_search_form.html.erb
index 66ee7039a..6e3731063 100644
--- a/app/views/media/catalog/_search_form.html.erb
+++ b/app/views/media/catalog/_search_form.html.erb
@@ -18,16 +18,20 @@
       <% if purpose == 'clicker' %>
         <%= f.hidden_field :types, value: ['Question'] %>
       <% end %>
-      <div class="custom-control custom-checkbox mb-2">
-        <%= f.check_box :all_types,
-                        id: 'search_all_media_types',
-                        class: 'custom-control-input',
-                        checked: purpose.in?(['media', 'clicker']),
-                        data: { id: 'search_media_types'} %>
-        <%= f.label :all_media_types,
-                    t('basics.all'),
-                    { class: 'custom-control-label' } %>
-      </div>
+      <% if purpose == 'media' %>
+        <div class="custom-control custom-checkbox mb-2">
+          <%= f.check_box :all_types,
+                          id: 'search_all_media_types',
+                          class: 'custom-control-input',
+                          checked: purpose.in?(['media', 'clicker']),
+                          data: { id: 'search_media_types'} %>
+          <%= f.label :all_media_types,
+                      t('basics.all'),
+                      { class: 'custom-control-label' } %>
+        </div>
+      <% else %>
+        <%= f.hidden_field :all_types, value: '0' %>
+      <% end %>
     </div>
     <div class="col-6 col-lg-3 form-group">
       <%= f.label :teachable_ids, t('basics.associated_to') %>

From 765c2f781e74b4e702d66bd0f5dd368ba9a8ab38 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Mon, 15 May 2023 17:44:42 +0200
Subject: [PATCH 17/22] enforce rubocop rules

---
 app/models/medium.rb | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/app/models/medium.rb b/app/models/medium.rb
index f3a8f8eb6..3c1a93b94 100644
--- a/app/models/medium.rb
+++ b/app/models/medium.rb
@@ -287,10 +287,10 @@ def self.search_by(search_params, page)
     # is seleted
     if search_params[:all_types] == '1'
       search_params[:types] = if search_params[:from] == 'start'
-                                Medium.generic_sorts
-                              else
-                                []
-                              end
+        Medium.generic_sorts
+      else
+        []
+      end
     end
     search_params[:teachable_ids] = TeachableParser.new(search_params)
                                                    .teachables_as_strings

From 5fce92457178bf74ca7de5cea596acf2804b34e7 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Mon, 15 May 2023 18:30:02 +0200
Subject: [PATCH 18/22] make count faster

---
 app/controllers/users_controller.rb | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index b5873fe28..0f03a0aca 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -11,7 +11,8 @@ def current_ability
 
   def index
     authorize! :index, User.new
-    @generic_users_count = User.where.not(id: @elevated_users.pluck(:id)).count
+    @generic_users_count = User.select(:id)
+                               .where.not(id: @elevated_users.pluck(:id)).count
   end
 
   def edit

From 1c7e0d1516efdac8b8abc55d0705063ce30fce02 Mon Sep 17 00:00:00 2001
From: Splines <37160523+Splines@users.noreply.github.com>
Date: Mon, 15 May 2023 19:00:44 +0200
Subject: [PATCH 19/22] Fix flickering for quiz previews (#502)

* Prevent flickering when quiz search results show up

* Remove user slug from StackOverflow link

* Get rid of unnecessary function
---
 app/views/media/fill_quizzable_preview.coffee | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/app/views/media/fill_quizzable_preview.coffee b/app/views/media/fill_quizzable_preview.coffee
index a9d215ab6..84c67f325 100644
--- a/app/views/media/fill_quizzable_preview.coffee
+++ b/app/views/media/fill_quizzable_preview.coffee
@@ -1,3 +1,6 @@
+# https://stackoverflow.com/a/36227664/
+oldScrollPos = Math.max(document.body.scrollTop, document.documentElement.scrollTop)
+
 $('#mediumPreview').empty()
   .append '<%= j render partial: "quizzes/edit/vertex_status",
                         locals: { quizzable: @quizzable } %>'
@@ -27,4 +30,6 @@ renderMathInElement mediumPreview,
       display: true
     }
   ]
-  throwOnError: false
\ No newline at end of file
+  throwOnError: false
+
+window.scrollTo(0, oldScrollPos)

From 4ad473f25c248d1dba86ed727b3b65b5a9876d25 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Tue, 16 May 2023 00:18:46 +0200
Subject: [PATCH 20/22] enforce rubocop recommendation

---
 app/helpers/media_helper.rb | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/app/helpers/media_helper.rb b/app/helpers/media_helper.rb
index cfd036ebc..711a57dfa 100644
--- a/app/helpers/media_helper.rb
+++ b/app/helpers/media_helper.rb
@@ -109,7 +109,9 @@ def media_sorts_select(purpose)
     return add_prompt(Medium.select_quizzables) if purpose == 'quiz'
     return Medium.select_question if purpose == 'clicker'
     return add_prompt(Medium.select_importables) if purpose == 'import'
-    return add_prompt(Medium.select_generic) if !current_user.admin_or_editor?
+    unless current_user.admin_or_editor?
+      return add_prompt(Medium.select_generic)
+    end
 
     add_prompt(Medium.select_sorts)
   end

From cb4050165974ffd994bc40780baa441ca4ea7004 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Wed, 17 May 2023 14:23:56 +0200
Subject: [PATCH 21/22] add linebreak in if statement

---
 app/models/medium.rb | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/app/models/medium.rb b/app/models/medium.rb
index 3c1a93b94..124395eac 100644
--- a/app/models/medium.rb
+++ b/app/models/medium.rb
@@ -286,11 +286,12 @@ def self.search_by(search_params, page)
     # generic media sorts as results even if the 'all' radio button
     # is seleted
     if search_params[:all_types] == '1'
-      search_params[:types] = if search_params[:from] == 'start'
-        Medium.generic_sorts
-      else
-        []
-      end
+      search_params[:types] =
+        if search_params[:from] == 'start'
+          Medium.generic_sorts
+        else
+          []
+        end
     end
     search_params[:teachable_ids] = TeachableParser.new(search_params)
                                                    .teachables_as_strings

From cb46762b38cf9b6820842ce27f1b5e159f702c76 Mon Sep 17 00:00:00 2001
From: fosterfarrell9 <28628554+fosterfarrell9@users.noreply.github.com>
Date: Mon, 29 May 2023 11:40:59 +0200
Subject: [PATCH 22/22] Use default version of commontator gem instead of own
 fork (#509)

* use default version of commontator gem instead of own fork

* enforce rubocop layout

* refactor customization of create comment action and add comments
---
 Gemfile                                       |   4 +-
 Gemfile.lock                                  |  16 +-
 .../commontator/comments_controller.rb        | 205 ++++++++++++++++++
 config/application.rb                         |   4 +
 4 files changed, 215 insertions(+), 14 deletions(-)
 create mode 100644 app/controllers/commontator/comments_controller.rb

diff --git a/Gemfile b/Gemfile
index d24e6e02c..659c4e8c0 100644
--- a/Gemfile
+++ b/Gemfile
@@ -91,9 +91,7 @@ gem "sidekiq-cron", "~> 1.1"
 gem "faraday", "~> 1.8"
 gem "globalize"
 gem "globalize-accessors"
-gem "commontator",
-  git: "https://github.com/MaMpf-HD/commontator.git",
-  branch: "main"
+gem "commontator"
 gem "acts_as_votable"
 gem "sprockets-rails",
   git: "https://github.com/rails/sprockets-rails",
diff --git a/Gemfile.lock b/Gemfile.lock
index 5f8fb5465..34c4f3ef3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,13 +1,3 @@
-GIT
-  remote: https://github.com/MaMpf-HD/commontator.git
-  revision: 38b25d2f3f4e4e2d1a0a7b608f04c579a93125f9
-  branch: main
-  specs:
-    commontator (7.0.0)
-      rails (>= 6.0)
-      sprockets-rails
-      will_paginate
-
 GIT
   remote: https://github.com/rails/sprockets-rails
   revision: 73e7351abff3506f6dca6b2da8abedfd5c7c0d77
@@ -174,6 +164,10 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
+    commontator (7.0.0)
+      rails (>= 6.0)
+      sprockets-rails
+      will_paginate
     concurrent-ruby (1.2.2)
     connection_pool (2.4.0)
     content_disposition (1.0.0)
@@ -674,7 +668,7 @@ DEPENDENCIES
   cancancan
   clipboard-rails
   coffee-rails (~> 5.0.0)
-  commontator!
+  commontator
   coveralls
   cypress-on-rails (~> 1.0)
   dalli (>= 2.7)
diff --git a/app/controllers/commontator/comments_controller.rb b/app/controllers/commontator/comments_controller.rb
new file mode 100644
index 000000000..641db8b0c
--- /dev/null
+++ b/app/controllers/commontator/comments_controller.rb
@@ -0,0 +1,205 @@
+# The CommmentsController is copied from the Commontator gem
+# Only minor customizations are made
+class Commontator::CommentsController < Commontator::ApplicationController
+  before_action :set_thread, only: [:new, :create]
+  before_action :set_comment_and_thread, except: [:new, :create]
+  before_action :commontator_set_thread_variables,
+                only: [:show, :update, :delete, :undelete]
+
+  # GET /comments/1
+  def show
+    respond_to do |format|
+      format.html { redirect_to commontable_url }
+      format.js
+    end
+  end
+
+  # GET /threads/1/comments/new
+  def new
+    @comment = Commontator::Comment.new(thread: @commontator_thread,
+                                        creator: @commontator_user)
+    parent_id = params.dig(:comment, :parent_id)
+    unless parent_id.blank?
+      parent = Commontator::Comment.find parent_id
+      @comment.parent = parent
+      @comment.body = "<blockquote><span class=\"author\">#{
+          Commontator.commontator_name(parent.creator)
+        }</span>\n#{
+          parent.body
+        }\n</blockquote>\n" if [:q,
+                                :b].include? @commontator_thread.config.comment_reply_style
+    end
+    security_transgression_unless @comment.can_be_created_by?(@commontator_user)
+
+    respond_to do |format|
+      format.html { redirect_to commontable_url }
+      format.js
+    end
+  end
+
+  # POST /threads/1/comments
+  def create
+    @comment = Commontator::Comment.new(
+      thread: @commontator_thread, creator: @commontator_user, body: params.dig(
+        :comment, :body
+      )
+    )
+    parent_id = params.dig(:comment, :parent_id)
+    @comment.parent = Commontator::Comment.find(parent_id) unless parent_id.blank?
+    security_transgression_unless @comment.can_be_created_by?(@commontator_user)
+
+    respond_to do |format|
+      if params[:cancel].blank?
+        if @comment.save
+          sub = @commontator_thread.config.thread_subscription.to_sym
+          @commontator_thread.subscribe(@commontator_user) if sub == :a || sub == :b
+          subscribe_mentioned if @commontator_thread.config.mentions_enabled
+          Commontator::Subscription.comment_created(@comment)
+          # The next line constitutes a customization of the original controller
+          update_unread_status
+
+          @commontator_page = @commontator_thread.new_comment_page(
+            @comment.parent_id, @commontator_show_all
+          )
+
+          format.js
+        else
+          format.js { render :new }
+        end
+      else
+        format.js { render :cancel }
+      end
+
+      format.html { redirect_to commontable_url }
+    end
+  end
+
+  # GET /comments/1/edit
+  def edit
+    @comment.editor = @commontator_user
+    security_transgression_unless @comment.can_be_edited_by?(@commontator_user)
+
+    respond_to do |format|
+      format.html { redirect_to commontable_url }
+      format.js
+    end
+  end
+
+  # PUT /comments/1
+  def update
+    @comment.editor = @commontator_user
+    @comment.body = params.dig(:comment, :body)
+    security_transgression_unless @comment.can_be_edited_by?(@commontator_user)
+
+    respond_to do |format|
+      if params[:cancel].blank?
+        if @comment.save
+          subscribe_mentioned if @commontator_thread.config.mentions_enabled
+
+          format.js
+        else
+          format.js { render :edit }
+        end
+      else
+        @comment.restore_attributes
+
+        format.js { render :cancel }
+      end
+
+      format.html { redirect_to commontable_url }
+    end
+  end
+
+  # PUT /comments/1/delete
+  def delete
+    security_transgression_unless @comment.can_be_deleted_by?(@commontator_user)
+
+    @comment.errors.add(:base,
+                        t('commontator.comment.errors.already_deleted')) \
+      unless @comment.delete_by(@commontator_user)
+
+    respond_to do |format|
+      format.html { redirect_to commontable_url }
+      format.js { render :delete }
+    end
+  end
+
+  # PUT /comments/1/undelete
+  def undelete
+    security_transgression_unless @comment.can_be_deleted_by?(@commontator_user)
+
+    @comment.errors.add(:base, t('commontator.comment.errors.not_deleted')) \
+      unless @comment.undelete_by(@commontator_user)
+
+    respond_to do |format|
+      format.html { redirect_to commontable_url }
+      format.js { render :delete }
+    end
+  end
+
+  # PUT /comments/1/upvote
+  def upvote
+    security_transgression_unless @comment.can_be_voted_on_by?(@commontator_user)
+
+    @comment.upvote_from @commontator_user
+
+    respond_to do |format|
+      format.html { redirect_to commontable_url }
+      format.js { render :vote }
+    end
+  end
+
+  # PUT /comments/1/downvote
+  def downvote
+    security_transgression_unless @comment.can_be_voted_on_by?(@commontator_user) && \
+                                  @comment.thread.config.comment_voting.to_sym == :ld
+
+    @comment.downvote_from @commontator_user
+
+    respond_to do |format|
+      format.html { redirect_to commontable_url }
+      format.js { render :vote }
+    end
+  end
+
+  # PUT /comments/1/unvote
+  def unvote
+    security_transgression_unless @comment.can_be_voted_on_by?(@commontator_user)
+
+    @comment.unvote voter: @commontator_user
+
+    respond_to do |format|
+      format.html { redirect_to commontable_url }
+      format.js { render :vote }
+    end
+  end
+
+  protected
+
+    def set_comment_and_thread
+      @comment = Commontator::Comment.find(params[:id])
+      @commontator_thread = @comment.thread
+    end
+
+    def subscribe_mentioned
+      Commontator.commontator_mentions(@commontator_user, @commontator_thread,
+                                       '')
+                 .where(id: params[:mentioned_ids])
+                 .each do |user|
+        @commontator_thread.subscribe(user)
+      end
+    end
+
+    # This method ensures that the unread_comments flag is updated
+    # for users affected by the creation of a newly created comment
+    # It constitues a customization
+    def update_unread_status
+      medium = @commontator_thread.commontable
+      return unless medium.released.in?(['all', 'users', 'subscribers'])
+
+      relevant_users = medium.teachable.media_scope.users
+      relevant_users.where(unread_comments: false)
+                    .update_all(unread_comments: true)
+      @update_icon = relevant_users.exists?(current_user.id)
+    end
+end
diff --git a/config/application.rb b/config/application.rb
index 205b7aca0..69d2fb63e 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -56,6 +56,10 @@ def self.all
         end
       end
     end
+    # Make sure that our custom commontator controllers are loaded
+    # instead of the default ones
+    # see https://github.com/lml/commontator/issues/200#issuecomment-1231456146
+    Commontator::Engine.config.autoload_once_paths = []
   end
 end