Hi @andrew_s@piefed.social/@freamon and @nutomic@lemmy.ml —I'm working (not-so-secretly) on refactoring NodeBB so that it is able to "browse" remote audiences/group actors, and that would include things like PieFed and Lemmy communities.
N.B. Given varied nomenclature (group/category/community/subforum), the ForumWG calls this structure an "audience".
Where I am at now is working through the logic for slotting an object into a category.
The most obvious choice here would be to look at as:audience. It's even specified in 1b12, and the majority of threaded implementations follow 1b12.
I am making this post because nutomic explicitly removed the audience from being served in Lemmy (as of January this year), so I don't think relying on that property would be wise.
I asked in that issue whether Lemmy finds community via to/cc (it does). Does PieFed do the same?
Would this also open up the possibility of a topic/context being part of multiple audiences/communities? Interesting...
Yes - PieFed does the same. It looks in 'audience', then 'cc', then 'to'. It has to, to support all the platforms that haven't adopted 'audience. It's a convenient field, but PieFed won't be affected if Lemmy goes through with removing it.
Not at present. If you do something like
cc: [community1, community2]it will only go to community1 (on both Lemmy and PieFed). There's so many activities that are effectively duplicates, both in normal operation and when platforms are bugged (both Lemmy and Mastodon have gone through phases of sending the same activity multiple times), that you need a way to make sure you're only processing one. On PieFed, this is done by having a UNIQUE constraint of the 'ap_id' column of the Post table (the ap_id of your post ishttps://community.nodebb.org/post/103806), so it means you can't have the same post in more than one community.