Cancel Method
This will cancel another entity's subscription to this entity's presence.
Syntax
xmpp.cancel(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
If for any reason the user should want to undo a previously granted subscription, this can be achieved through the Cancel method. The method will unsubscribe the target from this user's presence, thus preventing the target from seeing this user in the future.