[Mentions] Allow mentioning groups

[askvortsov1]

Feature Request

If groups are used to indicate teams, it would be useful to be able to mention a group of users and have all of them be notified.

[luceos]

A technical issue with this is that one would have to prevent users to use the same slug or maybe prefix the slug with group-?

[askvortsov1]

I've been in favor of requiring unique slugs for groups (in addition to the name) for a while now, provisioning based on ID is an absolute headache

[clarkwinkelmann]

This raises the question of which part of our codebase should be responsible for each of those features:

• Which one registers group slugs
• Which one verifies the uniqueness of slugs across usernames and groups

I expect some complicated settings to be needed for such a feature due to the potential for abuse.

Maybe it would make more sense to delegate this to some kind of "Teams" community extension which would handle everything without over-complicating our core software and core extensions.

What would be the use cases of a group mention extension be and why would it belong in the core ecosystem? I don't think I have seen many requests for such a feature.

[askvortsov1]

If we go the route in https://github.com/flarum/core/issues/1734#issuecomment-644391424, we don't need slugs for groups, and can just store the group ID, preixed by "G". That would alleviate all these issues

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. We do this to keep the amount of open issues to a manageable minimum.
In any case, thanks for taking an interest in this software and contributing by opening the issue in the first place!

[tankerkiller125]

Still relevant, possibly something to work out during the UTF-8 work for beta 15

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. We do this to keep the amount of open issues to a manageable minimum.
In any case, thanks for taking an interest in this software and contributing by opening the issue in the first place!

[stale]

We are closing this issue as it seems to have grown stale. If you still encounter this problem with the latest version, feel free to re-open it.