I may have got it working, using the Webmention plugin and a couple filters.
Publishing a custom post type doesn’t automatically send anything, for me. I have to manually call `Webmention_Sender::send_webmentions()`. Also, because I often rely on Mastodon or Twitter to autolink URLs, I had to use the `webmention_links` filter and run `make_clickable()` on some posts first, for the plugin to detect any targets.
Why would I want to do all that? Well, because I might be able to retire my own, dead-simple “Webmention Comments” plugin.
Fun fact: I did programmatically declare support for `webmentions` ...
Receiving webmentions doesn't work either, for my setup. (`webmention_url_to_postid` does not return the proper post ID.) Might revert to my own plugin, then.
Although ... `webmention_url_to_postid` _is_ filterable.
Seems WP's own `url_to_postid()` somehow returns 0 for any and all of my statuses. Probably due to my somewhat bizarre setup. Seems to work alright, though, with a quickly thrown together filter in place.
One thing I'd like to do, still, is replace Bridgy's URL with the actual source. Which would require filtering `webmention_comment_data` and parse the source's microformats ... (Although I've also installed Semantic Linkbacks, it doesn't seem to cover that part.)
Sometimes a _tiny_ plugin that does _exactly_ what you want, is actually quite nice! (The alternative is stacking 3rd-party plugins on top of each other and filtering the heck out of _everything_.)
Never mind! The `semantic_linkbacks_canonical` comment meta field contains exactly what I need. (Up next: adapt the front end to include it.)
And I think I've just successfully used the `preprocess_comment` filter to _locally_ cache avatars.
Not to self: could this be due to my marking posts 'private' when overriding their custom post type properties?
Server run by the main developers of the project It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!