I have discovered, I believe, the source of the problem ... but I''m not sure the consequences of it.

It seems if I am disconnected (e.g. I just close the browser in which my chat client is running) from the server without ever officially leaving the room, the chat server still shows me as being in the room ... and if I re-enter the room after re-launching the chat client, I get no presence event, no room join event, and no subject change event (presumably because the server believes I was already in the room).

This seems to me a problem since I cannot ever guarantee that every client will have an opportunity to leave the room before disconnecting from the server. What if the network just goes down temporarily? Shouldn''t the server detect when the connection has been dropped and automatically remove the user from any rooms they were in?

As things stand right now, if I get disconnected abnormally, any attempt to reconnect doesn''t work right because I don''t get all the events I expect to get after I am logged in. Has anyone else dealt with this problem already? Am I missing something?

Bill Bailey

Here goes one more time ... is anybody there?

I have discovered that if I can arrange to have a leave room message sent to the server right before I send it a join room message, it fixes the problem. That is, the leave message removes the old ''stale'' user and then the same user can enter the room once again. However, the current XIFF API only sends the leave room message if the user is active in the room ... and the active flag is maintained on the client side. This means that if the client abnormally exits such that the client-side state is lost, the leave room message won''t be sent even if you call the Room.leave() method. I had to remove the check

if ( isActive() ) {

}

from the leave method to ensure that a message is sent each time leave() is called regardless of whether the client believes the user is in the room or not. It seems to work.

However, even though the server doesn''t seem to mind getting a leave message when the user isn''t actually in the room, it makes me a little nervous since this still seems like a bit of a hack. I have another forum entry going regarding what I think is the best solution ... to have the server remove the user from the room automatically as part of cleaning up the session on a disconnect. However, it seems to me that there are a couple of ways to improve on the XIFF API as well.

1) Add an optional parameter (default to false) to leave() which forces the presence message to be sent whether or not the client thinks the user is in the room. I plan to make that change myself.

2) Have the isActive() method determine whether the user is active in the room by querying the server rather than maintaining this information on the client where it will be lost if the client abnormally exits. I need to research the appropriate message for making this query, but I am fairly certain it is possible.

Any comments, criticisms, warnings, or whatever?

Bill