Is it possible to detect if a user is already logged
into a jabber server? This way the application can
inform the user that the they are already logged in
and optionally quit or take over the connection.
You can check for the user’‘s presence to detect if a user is already logged into an XMPP server. You can check even if you are connected in another client and then react accordingly. FYI, your checking will be valid only if the other user didn’'t change his/her presence to invisible.
This way apps don’'t have to fight to share a connection.
I didn’'t understand why would they have to fight for a connection. If you have the same user connected twice (using different clients) then you will have a connection for each logged user.