DO NOT MERGE | new calendar endpoints

[carstingaxion]

Original PR description

As a proof-of-concept PR, this code needs for sure some orchestration!

The used anonymous functions are my preferred way of experimenting, but not meant to stay.

I can see 3 different ways to go on:

1. a custom class-add-to-calendar.php
2. Or even a further abstraction into another new class-rewrite-api.php that handles all the rewrites stuff and is only used by the current class-event.php
3. Or a new class-endpoints.php, that could also be the future home for Add subscribeable Ical feeds #603
4. Or maybe there is even better places within the existing code base?

Following path number 2 could be interesting for the future, as it could be reused, if GatherPress would want to create /tickets or /qr endpoints on events, for example. Long time ago created a similar abstraction to route AJAX requests, because it was (maybe still is) usually around 10 times faster than the REST API.

———

I’ve also tried using add_rewrite_endpoint() in the first run, but this would have added the new endpoints to all EP_PERMALINK rewrites, which would have meant: all non-hierarchical post types. In that case, I would have had to set custom 404s on all non-event post types, which ended up being very tedious and a lot of additional code. That’s why I went with add_rewrite_rule() which allows a restriction on one post type.

Description of the Change

This PR add several new URL endpoints to events, one per each add-to-calendar link. The new endpoints are:

• example.org/event/my-sample-event/ical
• example.org/event/my-sample-event/iCal (Alias for /ical)
• example.org/event/my-sample-event/outlook (Alias for /ical)
• example.org/event/my-sample-event/googlecalendar
• example.org/event/my-sample-event/yahoocalendar

With the original intention to help with #704, this PR also does some more subtle changes to the generated ics file, like changing its default line breaks.

Because this renders into a sites frontend output, this PR additionally introduces a way to overwrite the generated iCal via a theme template. This opens another way of extension and can be used to test this PR.

With the original intention to help with #704, this PR also does some more subtle changes [...]

Can be stated as totally outdated!

Unfortunately, this PR does NOT help with #704,
but instead has grown from 193 to 2607 lines of code and now closes #603 instead.

An extensive description can be found in a new /docs/developer/custom-url-endpoints article, that is also part of this PR.

This PR introduces the following of new endpoints:

• example.org/event/my-sample-event/ical

  provides a download-able .ics file in ical format.

• example.org/event/my-sample-event/outlook

  provides the same download-able file as an alias.

• example.org/event/my-sample-event/google-calendar

  redirects to create a new event in Google Calendar.

• example.org/event/my-sample-event/yahoo-calendar

  redirects to create a new event in Yahoo Calendar.

• example.org/event/feed/ical

  provides a subscribe-able event feed in ical format with all events of the site.

• example.org/venue/my-sample-venue/feed/ical

  provides a subscribe-able event feed in ical format with all events at that venue.

• example.org/topic/my-sample-topic/feed/ical

  provides a subscribe-able event feed in ical format with all events grouped into that topic.

How to test the Change

• Test the Add to Google calendar
  1. (You need an google account & use their calendar)
  2. Go to the frontend of any event and hit the the Add to calendar > Google button
  3. Confirm that the drafted event in the Google calendar matches the GatherPress event
• Test the Add to Yahoo calendar
  1. (You need an yahoo account & use their calendar)
  2. Go to the frontend of any event and hit the the Add to calendar > Yahoo button
  3. Confirm that the drafted event in the Yahoo calendar matches the GatherPress event
• …
• create a ical-download.php file and put it at the root of your active theme to overwrite the plugin template
  1. Create that file
  2. Put some echo ‚hello themed iCal world‘; into it
  3. Go to the frontend of any event and hit the the Add to calendar > iCal button (to make use of your template)
• https://icalendar.org/validator.html

Changelog Entry

Added - Human readable, shareable and subscribe-able „Add to calendar“ links for each event.

Credits

Props @carstingaxion

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly !!!
  • /readme.md
  • /docs/contributor/unit-tests
  • /docs/developer/custom-url-endpoints
  • /docs/developer/theme-customizations
• I have added tests to cover my change.
• All new and existing tests pass.

Related PRs that can be reviewed & merged after this:

• NEW Example from docs/developer/custom-url-endpoints gatherpress-awesome#3
• TRY: Register a block template for a new /rsvp endpoint carstingaxion/gatherpress#73

To get the new endpoints into the block-editor, one of the following would be required:

• [Block Library - Post Terms]: Add dynamic variations of feeds WordPress/gutenberg#65351
  OR
• https://github.com/carstingaxion/gatherpress-feed-buttons

[mauteri]

Thanks for your review @mauteri, but that was exactly what I wanted to pretend you from with my comment and the PR description.

I meant to start with a more strategic What-should-go-where before going into the details.

What do you think?

Sorry, I'm still a bit brain dead from being off for 2 weeks and trying to get back in the flow of things. I think the class-calendar.php (or class-add-to-calendar.php... I like the former a bit more because it is a shorter class name) is the approach I would go with. And move all calendar-related methods to that new class. Smaller, concise classes are easier to maintain and much more approachable.

[github-actions]

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[carstingaxion]

Hello @mauteri ,

I've updated the PR description with more relevant info and fixed the simple errors.

The remaining CS failures and Unit test failures are kind of intentional, to remind us what needs attention.

I will now not be able to add some helping review comments, but open it up for Reviews anyway.
If someone has time and wants to take a look, it would be a pleasure.

[carstingaxion]

I'm going to start adding some review-comments for you now @mauteri. Would be cool, if you find the time (or someone else) to go trough all of this me...melange.

[carstingaxion]

@mauteri I added 16 comments to help navigate to the most problematic parts.

[shawfactor]

Does this provide a general event feed, listing all events fit the site in iCal

e.g. example.org/events/feed/ical/

?

And does this also support taxonomies

?

e.g. example.org/events/feed/ical/topic/parents:

Pete

[carstingaxion]

Hello Pete,

yes that's correct.

Just that this is the first PR, which is and will be replaced by #928 and #955

Additionally #929 contains a lot documentation about all this.

Please have a look and tell me what you think!