/activitypub_comments_like_dislike_shim

Shim to connecti ActivityPub plugin to Comments Like Dislike plugin

Primary LanguagePHPGNU General Public License v3.0GPL-3.0

activitypub_comments_like_dislike_shim

Shim to connect ActivityPub plugin to Comments Like Dislike plugin

This plugin allows "like" and "unlike" reactions from ActivityPub to show up on a Wordpress blog.

This plugin is just a proof of concept, do not use it.

Demo

Jem is a Wordpress user. She publishes a post.

Post on the Jem and the Holograms blog, reading "Jem is Back. Jem and the Holograms are back in the studio". There is a comments box, but no comments yet. In the top right corner an avatar indicates that Jem is logged in.

Note that there are no like or dislike buttons on the post. The Comments Like Dislike plugin, as its name suggests, allows likes and dislikes only on comments, not posts.

Kimber is another user of Jem's blog. She makes a comment.

The same post now has a comment from Kimber at the bottom, consisting of three flame emojis. Above the comment a warning reads "Your comment is awaiting moderation. This is a preview; your comment will be visible after it has been approved." In the top right corner an avatar indicates that Kimber is logged in.

This comment goes into the moderation queue on the blog. When Jem approves it, it shows up under the post. Notice the like and dislike buttons. As yet no-one has liked anything.

!The comment no longer shows the warning. Underneath the comment there are thumbs-up and thumbs-down icons. Neither of them yet has a count.

Shana is a Friendica user. (Mastodon is more common than Friendica, but Friendica is what I'm familiar with.) Because Jem's blog has the ActivityPub plugin activated, anyone in the Fediverse, including Shana, can see Jem's post. In this case, Shana makes a comment.

Jem's post as shown on Friendica. There is only one comment, from Shana. It reads "Truly outrageous."

This comment also goes into the moderation queue on Jem's blog, and after Jem approves it, it also shows up under the post.

!Jem's post on the Jem and the Holograms blog. The comments from both Kimber and Shana are visible. Both have thumbs-up and thumbs-down icons, none of them with a count.

Aja is another Friendica user. She can see both Jem's post and Shana's comment. But she cannot see Kimber's comment, because the ActivityPub plugin does not yet support federation of Wordpress comments. (As of 2023-12-15 this feature is coming soon.) So she has no ability to "like" Kimber's comment, but she can click "like" button on Shana's comment.

Jem's post on Friendica, along with Shana's comment. The "Like" button is now highlighted, and below that it says "Aja likes this."

After a few minutes (Friendica uses a background process to publish messages) Aja's "like" arrives on the blog, so the "like" count now shows "1".

Jem's post on the blog, as before, but now there is a numeral "1" next to the thumbs-up icon.

Kimber also sees Shana's comment and likes it. Now the "like" count is "2".

Jem's post on the blog, with now a numeral "2" next to the thumbs-up icon. In the top right corner an avatar indicates that Kimber is logged in.

Raya is yet another Friendica user. She can see Shana's comment and Aja's "like", but not Shana's. This is again because the ActivityPub plugin does not yet support federation of likes. (And therefore the shim does not have any support either.) So the like count she sees is just "1". She likes the comment. She now sees a "like" count of "2".

Jem's post on Friendica, with Shana's comment showing. The "Like" button is again highlighted, and below that it says "Aja and Raya like this." In the top right corner an avatar indicates that Raya is logged in.

Again after a few minutes Raya's "like" arrives on the blog, and the count now shows "3".

Jem's post on the blog, and now there is a numeral "3" next to the thumbs-up icon.

Installation

To use this, you need to install the Comments Like Dislike plugin and the ActivityPub plugin. You then need to patch the Comments Like Dislike plugin with the supplied patch, like this:

$ svn patch comments_like_dislike_cld_ajax_php.patch
U         trunk/inc/classes/cld-ajax.php

Design

To make this work, the user needs three plugins: an ActivityPub plugin, a Comments Like Dislike plugin, and a weird "shim" plugin between the two. Why don't they just talk directly to each other?

They could do that. But there are other optional plugins that might consume events from the ActivityPub plugin, for example events or eCommerce plugins. Meanwhile there are other possible sources of likes and dislikes for the Comments Like Dislike plugin, for example Bluesky or Matrix. If both plugins have to support arbitrary numbers of partners, it greatly increases the maintenance cost. This comes at the expense of people who only want one or the other, not both.

Instead, this small implementation assumes that both plugins design their own independent sets of Wordpress hooks built around their own use cases. These can be stable, well-documented, and well-tested. Then there would be a separately maintained project to join these plugins together. As my code hopefully shows, the implementation can be very simple.

Missing Functionality

This is just a proof of concept. At least the following don't work:

  • Dislikes (as opposed to Likes)
  • Removing a like
  • Sending local likes over ActivityPub

Next Steps

The ActivityPub plugin has already been adapted in line with the above design. The Comments Like Dislike plugin, however, doesn't work unmodified. I would suggest the following approach:

  • Move functionality that records and calculates from cld-ajax.php into a separate class. This is probably a better design anyway.
  • Switch from cld_ips and cld_users to a single meta value supporting arbitrary types of likes. This would allow ActivityPub likes to have their own type.
  • Add hooks to add and remove likes from any source, and hooks after a like has been recorded.
  • Optionally, contrary to the design approach laid out above, actually include the relevant shims for ActivityPub.