Deleting a post vs deleting an entire comment tree
Technical Discussion
65
Posts
15
Posters
11
Views
-
This is slightly different from OP as you are talking about deleting a reply (ie
Note) with children, while OP is about deleting a top-level post with children. Nevertheless both can be represented in the same way over federation.Just sending out an individual Delete for every Object. I like this option the least, but it is very easy to implement and needs no changes in other software to work.
This would be terrible for performance when removing dozens or hundreds of comments at once. Rule of thumb should be one activity for one user action.
Make the target of the Delete an array. I’m honestly 50/50 on whether this is actually spec compliant, it’s not clear to me that it isn’t;
The problem with this is that some platforms might get the idea to delete multiple unrelated comments with a single activity, or even comments in different posts. Handling that would make the receiving logic unnecessarily complicated, and would also make it complicated to combine the modlog entries.
Same as option 1, a new property like removeChildren;
This is the simplest and best option.
I do agree that
with_replies, or similar, would be the easiest approach, but I don't think it is the most specific.The bool suggests that all replies to a given object are deleted. However, you do not know whether your idea of what the reply tree is matches that of the originating server (which replies are included, etc.?)
Remove(Context), on the other hand does imply both that the container is deleted, and all of its replies, which are dereferenceable by resolving the context directly. It also has the benefit of being able to provide a pointer to where it was removed from, which is useful.So to me it's not just a matter of preference, but that there are additional benefits to
RemoveI will of course concede that it is more work to deliver
Remove.cc thisismissem
-
mariusor@metalhead.club let's ask helge@mymath.rocks what implementor support for
Delete(Array)looks like LOL -
mariusor@metalhead.club let's ask helge@mymath.rocks what implementor support for
Delete(Array)looks like LOL@julian as long as it's in the spec, I don't really care.
If we all bow to inferior implementations the ecosystem will stagnate. Mastodon's quirks have done enough damage in my opinion. My choice is to be brave and build for the future.
PS. Not to brag or anything (🤞) but my implementation can operate on activities with arrays as object, actor, etc.
One thing where you can lead the way (because the threadiverse would really benefit from it) is to accept arrays in inReplyTo (where you put all the ancestors of the current post, not just the parent).
-
@nutomic I solved this by having an the instance be an actor that is an intermediary for all operations. All activities get CC'ed to the followers of the user actor, and of the instance actor. (replace instance with community/group, whatever you use as an aggregate element for your implementation)
This should cover all interested parties imho.
The potential downside is that instances need to explicitly operate between themselves with follow operations (which conveniently also solves the problem of unwanted interactions with less savory corners of the fediverse).
Like I said, a problem of addressing. :P
I'm sure that approach works as well. This would have been worth discussing 4 or 5 years ago when I was just implementing federation in Lemmy for the first time. By now FEP-1b12 is already an established standard which is used by various platforms, and it would be completely unfeasible to replace it with something else.
-
I fail to see what the fundamental difference is. If you are unsure about the target with
Delete/Object, you can also resolve thecontextof Object to figure that out. Anyway the instance where theGroupis hosted is always the authority, so the state there is the correct one.Actually I would rather think of this from a different perspective, namely from the perspective of the mod who clicks the remove button. That would happen when a post is offtopic or violates the rules, and then the intent clearly is to remove all replies as they are not useful. It wouldnt make sense to leave up a single reply two levels deep just because it wasnt included in the context for some reason.
-
@julian This sounds like an implementation detail to me. Some fedi platforms delete a child object when its parent is deleted, others don't.
If you want to make the removal of a subtree explicit, I'd recommend a
Removewhereobjectis an array (similar to what @mariusor suggested):Remove(object: Note[], target: Context)This also helps with migrating away from
Announce(Delete). I saw your FEP draft, will provide more feedback once I read it in full. -
I'm sure that approach works as well. This would have been worth discussing 4 or 5 years ago when I was just implementing federation in Lemmy for the first time. By now FEP-1b12 is already an established standard which is used by various platforms, and it would be completely unfeasible to replace it with something else.
@nutomic if you're implying that I should have spoken sooner, I'm pretty sure I did. I remember exchanging messages with both you and @dessalines when you started lemmy...
I have no specific memory about this topic, but to my recollection lemmy federation was pushed as fait-accomplit at one point without me seeing any previous research on your guys part.
-
@julian This sounds like an implementation detail to me. Some fedi platforms delete a child object when its parent is deleted, others don't.
If you want to make the removal of a subtree explicit, I'd recommend a
Removewhereobjectis an array (similar to what @mariusor suggested):Remove(object: Note[], target: Context)This also helps with migrating away from
Announce(Delete). I saw your FEP draft, will provide more feedback once I read it in full.silverpill@mitra.social mm I may have been premature regarding phasing out Announce(Delete).
nutomic@lemmy.ml made it clear that it wasn't going anywhere, and I will remove the "backwards compatibility" label from it in my draft.
-
@nutomic if you're implying that I should have spoken sooner, I'm pretty sure I did. I remember exchanging messages with both you and @dessalines when you started lemmy...
I have no specific memory about this topic, but to my recollection lemmy federation was pushed as fait-accomplit at one point without me seeing any previous research on your guys part.
Back then I didnt understand federation so well yet, so its possible that I didnt get what you were saying. And once I got the federation working there wasnt much reason to redo it in a different way which would effectively do the same thing.
-
@nutomic > Make the target of the Delete an array
It technically is because of JSON-LD (everything can be an array), however, software may not support it because it's pretty common for devs to treat AP as JSON instead of JSON-LD, so doing an assessment of compatibility would be suggested
@thisismissem @nutomic it's not a JSON-LD thing. it's the lack of schematic constraint within the Activity Vocabulary. any property not defined as "functional" can have more than one value.
-
@julian as long as it's in the spec, I don't really care.
If we all bow to inferior implementations the ecosystem will stagnate. Mastodon's quirks have done enough damage in my opinion. My choice is to be brave and build for the future.
PS. Not to brag or anything (🤞) but my implementation can operate on activities with arrays as object, actor, etc.
One thing where you can lead the way (because the threadiverse would really benefit from it) is to accept arrays in inReplyTo (where you put all the ancestors of the current post, not just the parent).
@mariusor @julian @helge i don't think "all the ancestors" makes sense for inReplyTo. by doing that, you are claiming that your post is a response to every post in the thread above it. multiple inReplyTo still makes sense but should be used only where you are actually responding to certain things. if you want ancestors, define a property "ancestors" which is a list of ancestors ordered in a specific way (like in the mastodon api)
-
@julian @rimu @nutomic @melroy @BentiGorlich is this a problem? it seems to only be a problem if you require the others to behave exactly as you do. the same "issue" applies to any activity in general. say you send a Delete; the others can do what they want:
- purge all children
- orphan all backlinked objects
- replace with a tombstone
- rewrite content to say "this post is deleted"
- ignore your activity as unauthorized or invalid or spamthe intent could be clearer...
-
@julian @rimu @nutomic @melroy @BentiGorlich is this a problem? it seems to only be a problem if you require the others to behave exactly as you do. the same "issue" applies to any activity in general. say you send a Delete; the others can do what they want:
- purge all children
- orphan all backlinked objects
- replace with a tombstone
- rewrite content to say "this post is deleted"
- ignore your activity as unauthorized or invalid or spamthe intent could be clearer...
@julian @rimu @nutomic @melroy @BentiGorlich the complicating factor here is not what other people do, but that you would be using the terms incorrectly or imprecisely according to their definition. this happens all the time in natural language where people sometimes use words they don't fully understand or use them with definitions not matching consensus. it's how we get people saying "literally" for things that are not literal, and other such slang.
-
@julian @rimu @nutomic @melroy @BentiGorlich the complicating factor here is not what other people do, but that you would be using the terms incorrectly or imprecisely according to their definition. this happens all the time in natural language where people sometimes use words they don't fully understand or use them with definitions not matching consensus. it's how we get people saying "literally" for things that are not literal, and other such slang.
trwnh@mastodon.social it's less so that I want receivers to do what I want (the ship has sailed on that), but rather that we have the opportunity to provide some guidance on preferred behaviour.
What's clear here is that there are going to be two separate actions, "Delete object and all children, recursively", or "Delete object but retain children".
We're discussing the best way to represent those two actions.
cc rimu@piefed.social nutomic@lemmy.ml silverpill@mitra.social
-
-
@julian @rimu @nutomic @silverpill well, you typically have no authority over "children", so you can't actually delete them. you can treat them as deleted locally (equivalent to garbage collection for orphan references), but as far as the outside world is concerned, you just deleted one object.
i think people should be more aware that orphaned references can and will happen. i'd personally leave them be. link rot is a thing, and those links aren't necessarily invalid, they're just stale.
-
@julian @rimu @nutomic @silverpill well, you typically have no authority over "children", so you can't actually delete them. you can treat them as deleted locally (equivalent to garbage collection for orphan references), but as far as the outside world is concerned, you just deleted one object.
i think people should be more aware that orphaned references can and will happen. i'd personally leave them be. link rot is a thing, and those links aren't necessarily invalid, they're just stale.
@julian @rimu @nutomic @silverpill put another way, there is no difference between a link that doesn't resolve because the resource was deleted and a link that doesn't resolve because the server was down or a link that doesn't resolve because you don't have authorization to see it. it's just a link that doesn't resolve, as far as you're concerned.
the same thing applies to moderation, not just deletion. a direct link might resolve, but the link is omitted from a curated view.
-
@julian @rimu @nutomic @silverpill put another way, there is no difference between a link that doesn't resolve because the resource was deleted and a link that doesn't resolve because the server was down or a link that doesn't resolve because you don't have authorization to see it. it's just a link that doesn't resolve, as far as you're concerned.
the same thing applies to moderation, not just deletion. a direct link might resolve, but the link is omitted from a curated view.
@julian @rimu @nutomic @silverpill essentially the difference between the two actions only exists internally, not externally.
whether to use a Delete or a Remove is a separate issue of semantics and authority.
whether to use an array of objects is a separate issue of batching and partial failure. semantically, there is no issue. "john deleted 10 posts" makes sense as a statement.
-
@julian @rimu @nutomic @silverpill essentially the difference between the two actions only exists internally, not externally.
whether to use a Delete or a Remove is a separate issue of semantics and authority.
whether to use an array of objects is a separate issue of batching and partial failure. semantically, there is no issue. "john deleted 10 posts" makes sense as a statement.
trwnh@mastodon.social nobody's deleting anything. We're only dealing with removing content.
(Which I now realize I worded incorrectly in OP, heh)
That it's a Delete is incidental (and unfortunate wording)
-
@julian you used the word Delete throughout, so i used the same word. either way, you might consider a policy of treating a context deletion as orphaning all items in the context and then you can optionally garbage-collect them. or not. it's up to you, really!
Gli ultimi otto messaggi ricevuti dalla Federazione
-
Okay, I've setup https://notes.socialcg.org/about
-
@julian i'd say the confusion is primarily that we've shifted topic around several different things and i'm still not sure which is the intended topic of the discussion :x
- deleting posts that are in a thread
- removing posts from a thread
- implications for downstream posts in a thread when some ancestor in the reply chain is deleted/removed
- deleting a thread that is in a forum
- removing a thread from a forum
- moving a thread to the "uncategorized" forum
- ...?
-
@julian if the intent is to signal what happens when nodebb moves a thread to "uncategorized", then i think the simplest thing is for nodebb to treat "uncategorized" as a forum in itself, still. you already assign them an id of -1, so you are in effect treating the "uncategorized" category as a category still.
-
@julian the confusing thing to me, though, is that both Delete and Remove already don't imply anything about posts in the thread if the thread is deleted/removed from the forum.
by default, if you Delete a thread, the forum might still have a broken link to the now-deleted thread, and the posts also have broken links to the thread.
by default, if you Remove a thread from the forum, the posts still exist within the thread.
-
trwnh@mastodon.social specifically however, is that you're not deleting the context. Just removing it.
NodeBB has the concept of a context not belonging to an audience (the "uncategorized" pseudo category.) in those specific situations, contexts would be removed from the audience, not deleted.
Lemmy and Piefed don't have these concepts, so they simply delete them. So therein lies some of the confusion I believe.
-
@julian like removing a whole thread from the forum? Remove(object=thread, target=forum)? this seems like something altogether different than removing posts from a thread.
removing threads from a forum is possible but if the thread is owned by the forum then the forum can also delete them.
the part that differs between impls is whether Delete(thing that is a context) should do anything to objects where context = the Delete.object, right? i think it makes the most sense to just orphan them.
-
trwnh@mastodon.social it signals that the actor is removing the context from the targeted audience.
The audience can optionally announce it, and receivers synchronizing with that audience (per 1b12) should follow suit and remove the context as well.
-
@julian what does Remove(Context) mean here?
