It would be possible to filter the rooms from this modal in Calendar:

@ChristophWurst is that a change you would be ok with?

the listener would update the timestamp

Which listener?

the listener would update the timestamp

Which listener?

The Talk internal listener https://github.com/nextcloud/spreed/blob/main/lib/Listener/CalDavEventListener.php

I see. What does it do? It sets room meta data to the event start? And if there is more than one event pointing to the same room the start becomes ambiguous?
Do you get the same inconsistency when an attendee moves their copy of an event?

I see. What does it do? It sets room meta data to the event start?

Yes, exactly. We want to reduce the items in the room list since we have quite some power users that have hundreds, if not thousands of rooms that are "single use" for a calendar event, so we filter out those types of rooms until we're closer to their start date.

And if there is more than one event pointing to the same room the start becomes ambiguous?

Exactly.

Do you get the same inconsistency when an attendee moves their copy of an event?

Currently, we don't since we simply overwrite the timestamp when it's a CalendarObjectUpdatedEvent. If we change the listener, we would produce an ambiguity for this use case instead (which is probably the more common one).

Which is why I would prefer if we could filter rooms that have an objectType event from the modal in calendar so they can't be chosen. Of course, nothing prevents a user from copy- pasting a conversation link to the location field, so some checks might still be needed... maybe a search for the LOCATION property on the CalDavBackend, which, if there's already an event with this link, would change the room type since it doesn't adhere to the constraints of a room type event.

Some points from our discussion:

• Rooms with recurrences should be converted to regular rooms in the CalDAV listener (as they are not a "disposable room")
• Check if the objectId is already a timestamp in CalDAV listener on creation, if it is, convert it to a regular room, because then we have 2 instances of usage. Don't do that, on update: On Update do a search instead.
• On frontend/clients, event rooms should not be able to change the title and description (as this should be updated by the CalDAV listener as well). You can change avatar in talk.
• We replace the calendar icon inside of the chat for event rooms (in the topbar) with a symbol that indicates that this room will be archived after 24h and actions. The actions should be in the menu, where we currently have "Schedule meeting".
• On frontend: Hide room type EVENT if object id is smaller (timestamp - 3600 * 24)
• On API: Archive room type EVENT if the last activty timestamp is (current - 3600*24*7) - i. e. if they haven't been used for a week and no new messages were sent
• When a call ends in the room type EVENT, show buttons to archive / delete the room immediately - similar to green "join call" button we have now in the chat area

Considerations:

• Deleting and restoring of calendar events changing the status
• Copying events are currently not handled

To Do Development CalDavListener:

• Split CalendarObjectCreated and CalendarObjectUpdated events to handle the difference with timestamps / search
• Search should compare UUID
• Update Title and Description from the Listener (for rooms)