ProbePresence Method
Use this method to probe for another entity's presence.
Syntax
xmpp.probePresence(jabberId, [callback])
Callback
The 'callback' parameter specifies a function which will be called when the operation completes (or an error is encountered). If the 'callback' parameter is not specified, then the method will block and will not return until the operation completes (or an error is encountered).
The callback for this method is defined as:
function(err){ }
'err' is the error that occurred. If there was no error, then 'err' is 'null'.
'err' has 2 properties which hold detailed information:
err.code err.message
Remarks
In the case that the user needs to update a particular entity's presence this method can be used to retrieve it. After a successful call, the server will either respond with the last known presence for Jabber, or will send a presence element of type "error". In either case, the respond will be returned by a Presence event.