After a time expires, my client wants us to prompt the user for a possible keepalive to the server. I put an AbstractAjaxBehavior in place, passed the URL to the client and issue the ajax request thusly:
Wicket.Ajax.ajax({u: document._sessionKeepAliveUrl});
The URL in the value there is:
./.?3-1.IBehaviorListener.0-
A breakpoint tells me the onrequest of the behavior is invoked. But then I get the following error on the client side:
Wicket.Ajax: Wicket.Ajax.Call.failure: Error while parsing response: TypeError: Cannot read properties of null (reading 'getElementsByTagName')
So the solution mostly works. The behavior doesn't do anything with the response. What am I doing wrong. Note, this is Wicket 6 (our client doesn't want to pay for the time to upgrade since they haven't decided on our next framework).
You need to add "wr": false to the attributes:
Wicket.Ajax.ajax({u: document._sessionKeepAliveUrl, "wr": false});
wr stands for "is Wicket Response" [1]. It tells Wicket Ajax/JS whether it should try to interpret the Ajax response or not.
By default Wicket.Ajax.get/post() deals with XML response generated by AbstractDefaultAjaxBehavior, but in your case you use its parent - AbstractAjaxBehavior, that may produce any kind of response, or even no response as in your case.