Blocks: Create a Live Schedule block

[ryelle]

Add a new block called "Live Schedule", which can be used on the Day of Event template (or any other page). Combined with #241, this will let organizers have total control over the content of the Day of Event template.

This also removes the need for a separate build script/process in mu-plugins/theme-templates, that will be removed in a following PR. It does remove the self-updating "Latest Posts" section, but organizers can use the Latest Posts block if they want, and this reduces the repeat API calls. If more organizers want this functionality we can see about hooking into the Latest Posts block.

Fixes #127 – You can customize the heading text and level in the block UI.
See #130 – Addresses a few issues from this issue

Screenshots

In wp-admin, it only displays a placeholder (for now). The headings are customized in the sidebar.

No sessions upcoming:

List of sessions (faked "now" to be 10am):

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Still to do (in following PRs)

• Fix issues with time
  • If we're after the start of the last event for a day, it says nothing's happening (we could check if there were other sessions on this day, and put up a "done for the day" message?)
  • If we're before the first event on the second day, it considers the last session of the prev day "on now".
• Remove stripTagsAndEncodeText and support diacritics.
• Audit the imports from the frontend script so we're not loading too much to the page
• Add a better, interactive preview in the editor
• (as mentioned) Remove the JS code from day of theme-templates.

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To test

• Create a few sessions that are happening now (or add a property to $data['live-schedule'] called nowOverride which should be a fake "now" in miliseconds).
• Add the Live Schedule block to a page.
• View it on the frontend, it should show you the current and upcoming sessions.

[melchoyce]

An idea for a placeholder state, using obviously fake session data:

[ryelle]

A future improvement could be to add a setting to restrict to a single track, so this block could be used on a livestream page.

[ryelle]

Rebased to remove the eslint require-jsdoc exceptions , and added the editor preview – so now it looks like this in the editor:

The data we use to populate that is in data/mock.js. It doesn't pull any API data, since the site probably doesn't have any active sessions when someone is editing the page.