Observing Login State by Combining Flows

EmergeTools · Jul 26, 2024 · 98a6258 · 98a6258
1 parent 15c5c0f
commit 98a6258
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Showing 3 changed files with 42 additions and 20 deletions.
diff --git a/android/app/src/main/java/com/emergetools/hackernews/data/HackerNewsWebClient.kt b/android/app/src/main/java/com/emergetools/hackernews/data/HackerNewsWebClient.kt
@@ -100,7 +100,7 @@ class HackerNewsWebClient(
     return PostInfo(
       id = itemId,
       upvoted = upvoteElement.hasClass("nosee"),
-      upvoteUrl = upvoteElement.attr("href")
+      upvoteUrl = BASE_WEB_URL + upvoteElement.attr("href")
     )
   }
 

diff --git a/android/app/src/main/java/com/emergetools/hackernews/features/comments/CommentsDomain.kt b/android/app/src/main/java/com/emergetools/hackernews/features/comments/CommentsDomain.kt
@@ -3,6 +3,7 @@ package com.emergetools.hackernews.features.comments
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
+import com.emergetools.hackernews.data.CommentFormData
 import com.emergetools.hackernews.data.CommentInfo
 import com.emergetools.hackernews.data.HackerNewsSearchClient
 import com.emergetools.hackernews.data.HackerNewsWebClient
@@ -12,8 +13,12 @@ import com.emergetools.hackernews.data.relativeTimeStamp
 import com.emergetools.hackernews.features.login.LoginDestinations
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.filterIsInstance
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
@@ -40,7 +45,8 @@ sealed interface CommentsState {
     val loggedIn: Boolean,
     val upvoted: Boolean,
     val upvoteUrl: String,
-    val postComment: PostCommentState?,
+    val commentText: String,
+    val formData: CommentFormData?,
     override val comments: List<CommentState>,
   ) : CommentsState {
     override val headerState = HeaderState.Content(
@@ -52,6 +58,15 @@ sealed interface CommentsState {
       upvoted = upvoted,
       upvoteUrl = upvoteUrl
     )
+    val postComment = formData?.let { data ->
+      PostCommentState(
+        parentId = data.parentId,
+        goToUrl = data.gotoUrl,
+        hmac = data.hmac,
+        loggedIn = loggedIn,
+        text = commentText
+      )
+    }
   }
 }
 
@@ -130,7 +145,24 @@ class CommentsViewModel(
   private val userStorage: UserStorage,
 ) : ViewModel() {
   private val internalState = MutableStateFlow<CommentsState>(CommentsState.Loading)
-  val state = internalState.asStateFlow()
+  private val loggedInFlow = userStorage.getCookie().map { !it.isNullOrEmpty() }
+
+  val state = combine(
+    loggedInFlow,
+    internalState.filterIsInstance<CommentsState.Content>()
+  ) { loggedIn, state ->
+    if (loggedIn != state.loggedIn) {
+      state.copy(
+        loggedIn = loggedIn
+      )
+    } else {
+      state
+    }
+  }.stateIn(
+    scope = viewModelScope,
+    started = SharingStarted.WhileSubscribed(),
+    initialValue = CommentsState.Loading
+  )
 
   init {
     viewModelScope.launch {
@@ -151,15 +183,8 @@ class CommentsViewModel(
             loggedIn = loggedIn,
             upvoted = pageInfo.postInfo.upvoted,
             upvoteUrl = pageInfo.postInfo.upvoteUrl,
-            postComment = pageInfo.commentFormData?.let { data ->
-              PostCommentState(
-                parentId = data.parentId,
-                loggedIn = loggedIn,
-                goToUrl = data.gotoUrl,
-                hmac = data.hmac,
-                text = ""
-              )
-            },
+            commentText = "",
+            formData = pageInfo.commentFormData,
             comments = comments,
           )
         }
@@ -195,9 +220,7 @@ class CommentsViewModel(
         val current = internalState.value
         if (current is CommentsState.Content) {
           internalState.value = current.copy(
-            postComment = current.postComment?.copy(
-              text = action.text
-            )
+            commentText = action.text
           )
         }
       }
@@ -207,9 +230,7 @@ class CommentsViewModel(
           val current = internalState.value
           if (current is CommentsState.Content && current.postComment != null) {
             internalState.value = current.copy(
-              postComment = current.postComment.copy(
-                text = ""
-              )
+              commentText = ""
             )
             val (parentId, gotoUrl, hmac, _, text) = current.postComment
             webClient.postComment(parentId, gotoUrl, hmac, text)

diff --git a/android/app/src/main/java/com/emergetools/hackernews/features/comments/CommentsScreen.kt b/android/app/src/main/java/com/emergetools/hackernews/features/comments/CommentsScreen.kt
@@ -176,7 +176,8 @@ private fun CommentsScreenPreview() {
         loggedIn = false,
         upvoted = false,
         upvoteUrl = "",
-        postComment = null,
+        commentText = "",
+        formData = null,
         comments = listOf(
           CommentState.Content(
             id = 1,