The XMPP roster takes some time to update after first connecting to Hangouts.
Thus if you do not wait before attempting to send a message, then it will not succeed as the recipient will not yet have been added to the roster despite actually being online.
Perhaps there is a way to find out if the roster has finished updating?
The XMPP roster takes some time to update after first connecting to Hangouts. Thus if you do not wait before attempting to send a message, then it will not succeed as the recipient will not yet have been added to the roster despite actually being online.
Perhaps there is a way to find out if the roster has finished updating?