[JDEV] question regarding jabber:x:conference

[Oliver George]

Hello,

I was looking at 
http://docs.jabber.org/draft-proto/html/conferencing.html regarding the 
prototype Generic Conferencing namespaces and protocol.

The thing that I've never understood is what happens when someone wants 
to leave a group... what would seem to happen is that their final nick 
will remain tied up and also everytime someone logs in their (now 
unused) member information will continue to be iq/set out to all new 
group members.

The two issues as i see it are:
1. how does a user indicate that they are leaving for good
2. how does the transport tell all users that the member is leaving for good

Perhaps it is helpful to consider this in some contexts:
- a room with 5~10 people at any one time (IRC style)
- a room with 200 people 'registered' but only 10 people in it at any 
one time

My thoughts are this:
- when a presence/unavailable is retrieved from a group member he is 
considered to have left for good (unless the are 'registered').
- to indicate a member has gone for good to other members send out a 
jabber:iq:browse where the user tag has no name attribute _or_ (if 
jabber:iq:browse tags are a complete roster) just send a new complete 
roster out.
- to be a persistant send a registration request to the group.... BUT 
only show that information in the jabber:iq:browse if they are in the 
room.  (else you might have to send 2000 user tags when the group only 
has 3 people in it)

Hope that makes sense, I'm pleased that the jabber:iq:conference 
protocol has been proposed we needed it.

Keep up the great work, Oliver.