Warning/notice when creating a post to a defederated instance

[0WN463]

Requirements

• [X] This is a feature request and not a bug report. Otherwise, please create a new bug report instead.
• [X] Please check to see if this request (or a similar one) already exists.
• [X] It's a single feature. Please don't request multiple features in one issue.

Describe the feature you'd like

(Still new to Lemmy, so pardon me if any of my terminologies are not accurate)

When creating a post to a community on a defederated instance, there is no warning for the user that the post will not be shown to the instance.

I was confused previously about several of my post not appearing on the target instance/community after posting them, which now I learnt is due to defederation.

I feel we should add a disclaimer or some notice to the user when trying to post to a community on defederated instance so that they are aware of this behaviour, especially since the instance dropdown in the post creation screen still contains communities from defederated instances.

[dessalines]

If your server is the one that's blocking another one, I believe we already throw a back-end error there.

But if its the receiving server, then its probably not doable. Your server doesn't know which servers are currently blocking it, since its blocked on the receiving side. So I don't know any way we could do this.

[0WN463]

Hmmm could you help check my situation, in case I get the terminology wrong?

So what happened was that my main account is on lemmy.cafe, and I tried to post to lemmy.ml.

From https://lemmy.cafe/instances, we see that lemmy.cafe blocked lemmy.ml, but I am still able to create a post from lemmy.cafe, but I was extremely confused cause my post didn't appear under lemmy.ml's search, but it appears in lemmy.cafe.

Is this the same as the situation you described?

Your server doesn't know which servers are currently blocking it, since its blocked on the receiving side.

Why not? I thought the flow would be user -> my home server -> receiving server, of which it would give a reply. If it was blocked, wouldn't the receiving server give a reply? How else would the home server know if the post is created successfully or not? Or am I understanding this wrongly, sorry that I am new to this.

[dessalines]

From https://lemmy.cafe/instances, we see that lemmy.cafe blocked lemmy.ml, but I am still able to create a post from lemmy.cafe, but I was extremely confused cause my post didn't appear under lemmy.ml's search, but it appears in lemmy.cafe.

That is a case we could potentially handle, since your instance knows about the block. We can't do the reverse direction though.

[Die4Ever]

But if its the receiving server, then its probably not doable. Your server doesn't know which servers are currently blocking it, since its blocked on the receiving side. So I don't know any way we could do this.

Wouldn't it show as an inactive instance due to an old timestamp for last activity? I forget what that table is, but I thought that dead instances check would cover this case somewhat. A warning that you're trying to post to a dead of defed instance sounds very helpful.

[dessalines]

Inactive doesn't necessarily mean de-fed. We don't know which servers have blocked ours, as we don't go out crawling for that info.

[Die4Ever]

Inactive doesn't necessarily mean de-fed. We don't know which servers have blocked ours, as we don't go out crawling for that info.

I agree inactive doesn't mean defed, but a general warning for trying to post to an unreachable server makes sense to me. The end result is the same, it won't work lol, generally it's a good idea to have a warning for something that is unlikely to work correctly.