alert error message for a missing javascript resource?

[Russell Morrisey <Ru...@missionse.com>]

wicket 1.4.9
When a wicket behavior tries to load a javascript resource from the response, I want to create some error handler (a javascript alert) that runs if the javascript package resource is not found.

I set an IAjaxCallDecorator which spits out a javascript string on failure, but the failure decoration isn't being used in the case where the script resource returns a 404. My link:

return new AjaxFallbackLink(linkId) {
                     protected IAjaxCallDecorator getAjaxCallDecorator() {
                           CompositeAjaxCallDecorator decorator = new CompositeAjaxCallDecorator();
                           decorator.setFailureDecorator(new SimpleScriptDecorator(
                                         "alert('An error occurred communicating with the server. Please contact a system administrator.');"));
                           return decorator;
                     }
...
              };

I can see that my CompositeAjaxCallDecorator generates the event handler correctly in the output, so I'm not going to post the code for that class. The output:

<a onclick="var wcall=wicketAjaxGet('../?wicket:interface=:6:contentPanel:tabPanel:tabs-container:tabs:1:link::IBehaviorListener:0:1',function() { }.bind(this),function() {
 alert('An error occurred communicating with the server. Please contact an AIMS administrator.');}.bind(this), function() {return Wicket.$('link49c') != null;}.bind(this));return !wcall;" id="link49c" href="../?wicket:interface=:6:contentPanel:tabPanel:tabs-container:tabs:1:link::ILinkListener::"><span>Import</span></a>

When I click on the link, the wicket ajax debug shows:

INFO: Initiating Ajax GET request on ../resources/com.csc.aims.wicket.behaviors.calldecorator.ClearFeedbackScriptDecorator/ClearFeedbackScriptDecorator.js
INFO: Invoking pre-call handler(s)...
INFO: focus removed from link49c
ERROR: Received Ajax response with code: 404
INFO: Invoking post-call handler(s)...
INFO: Invoking failure handler(s)...
INFO: focus set on link49c
INFO: focus removed from link49c

I did some debugging, and noticed that in wicket-ajax.js, the script element is loaded from the response using a second ajax request:

1613    // we need to schedule the request as timeout
1614    // calling xml http request from another request call stack doesn't work
1615    window.setTimeout(function() {
1616               var req = new Wicket.Ajax.Request(src, onLoad, false, false);
1617               req.debugContent = false;
1618               if (Wicket.Browser.isKHTML())
1619                           // konqueror can't process the ajax response asynchronously, therefore the
1620                           // javascript loading must be also synchronous
1621                           req.async = false;
1622               // get the javascript
1623               req.get();
1624    },1);

This second ajax request doesn't specify a failure handler, so I'm thinking that he's the culprit.

How can I fix this?

Thanks,
________________________________

RUSSELL E. MORRISEY
Programmer Analyst Professional
Mission Solutions Engineering, LLC

| Russell.Morrisey@missionse.com | www.missionse.com<http://www.missionse.com/>
304 West Route 38, Moorestown, NJ 08057-3212


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