Thank you again for your time, Igor. Your explanation makes sense by itself, but it is not my problem, I'm afraid... this thing can happen to me even the first time I load the page, without reloading at all.
I investigated deeper and I realised that what was happening was that, when the server received the request from the flash object for retrieving the data (a request on the IResourceListener interface of the DataPanel)... the onBeforeRender() method of the outer container was being executed some times (and this onBeforeRender created a new LoadingPanel, which is what caused the exception)... and this makes no sense to me. Let me put it clear, once loaded by the DataPanel onto the browser, the flash object requests: http://myserver/MyPage/wicket:interface/:5:outerpanel:panelloader:datapanel::IResourceListener:: Which means that it is calling the datapanel which created the flash object itself as a resource listener, to simply obtain a resource declared there (a WebResource object) containing a String of data in JSON format. In my understanding this request, which is executed via the XmlHttpRequest object in the browser, should never provoke "outerpanel"'s onBeforeRender() method to execute... but it does! I put a log sentence in this onBeforeRender method which outputs "RequestCycle.get().getRequest().getURL()" and I receive an URL like the one above... but only sometimes, only when it fails. Is this possible, is there something I am not understanding about the way this URL should be served? Thanks again, Daniel. 2009/4/22 Igor Vaynberg <igor.vaynb...@gmail.com>: > browsers are asynchronous, so you might have a race codition. eg > browser requests the data url and you press the refresh button, so now > there are two urls in the queue: the data and the page. if page is > processed first then the data url will fail because when the page is > first constructed you have a loading panel in there. makes sense? > > take a look at wicket's ajaxlazyloadingpanel, it might have a way to > handle this. > > -igor > > On Wed, Apr 22, 2009 at 10:23 AM, Daniel Fernandez > <daniel.f...@gmail.com> wrote: >> Thanks for your answer, Igor. >> >> Now I know what is happening more in detail. It is not easy to >> explain, sorry for the long text: >> >> I have: >> >> - DataPanel: a panel with data I want to show. >> >> - LoadingPanel: a panel which just shows a "loading..." image. >> >> - PanelLoader: a Panel with an inner panel called "content", which >> is loaded initially with LoadingPanel, and sets an AjaxTimerBehavior >> which polls the server until the data is ready, and then creates the >> DataPanel, replaces the inner "content" with this DataPanel, and stops >> the timer behavior. >> >> >> All this works perfectly until I use a subclass of DataPanel called >> FlashDataPanel which, for showing data, shows a flash object which in >> turn has to make a request from the browser to get its data. I offer >> this data to the flash object as a resource, by making this subclass >> of DataPanel implement IResourceListener, and implementing its >> "onResourceRequested" method. The URL I add to the flash object is >> obtained like: >> >> CharSequence dataPath = >> RequestCycle.get().urlFor(FlashDataContainer.this, >> IResourceListener.INTERFACE); >> return RequestUtils.toAbsolutePath( dataPath.toString() ); >> >> The problems seems to be that *sometimes, and only sometimes* (maybe >> once each 50 correct loads or so), the "onResourceRequested" method >> gets called on the LoadingPanel instead of the DataPanel... which is >> something strange to my eyes (unless there is something I don't >> understand, of course). The URL is created passing the >> FlashDataContainer.this object, so I cannot understand how it gets >> called on a LoadingPanel, which of course does not implement >> IResourceListener, and thus provokes this exception. >> >> Regards, >> Daniel. >> >> >> >> 2009/4/22 Igor Vaynberg <igor.vaynb...@gmail.com>: >>> why dont you set a breakpoint for classcastexception and see what it >>> is trying to cast to what. >>> >>> -igor >>> >>> On Wed, Apr 22, 2009 at 3:52 AM, Daniel Fernandez <daniel.f...@gmail.com> >>> wrote: >>>> Hello, >>>> >>>> I have a page which makes quite a heavy use of an >>>> AbstractAjaxTimerBehavior for retrieving the content of some Panels >>>> (and stops itself after the content is ready, like a sort of >>>> "polling") and I am getting a very strange exception which only seems >>>> to appear randomly: >>>> >>>> >>>> ------------- >>>> >>>> 2009-04-22 12:21:30,592 ERROR [RequestCycle] (RequestCycle.java:1463) >>>> - Method onResourceRequested of interface >>>> org.apache.wicket.IResourceListener targeted at component >>>> [MarkupContainer [Component id = content]] threw an exception >>>> org.apache.wicket.WicketRuntimeException: Method onResourceRequested >>>> of interface org.apache.wicket.IResourceListener targeted at component >>>> [MarkupContainer [Component id = content]] threw an exception >>>> at >>>> org.apache.wicket.RequestListenerInterface.invoke(RequestListenerInterface.java:199) >>>> at >>>> org.apache.wicket.request.target.component.BookmarkableListenerInterfaceRequestTarget.processEvents(BookmarkableListenerInterfaceRequestTarget.java:163) >>>> at >>>> org.apache.wicket.request.AbstractRequestCycleProcessor.processEvents(AbstractRequestCycleProcessor.java:92) >>>> at >>>> org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1192) >>>> at org.apache.wicket.RequestCycle.step(RequestCycle.java:1271) >>>> at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1370) >>>> at org.apache.wicket.RequestCycle.request(RequestCycle.java:501) >>>> at >>>> org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:455) >>>> at >>>> org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:288) >>>> at >>>> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215) >>>> at >>>> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188) >>>> at >>>> org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198) >>>> at >>>> org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) >>>> at >>>> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215) >>>> at >>>> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188) >>>> at >>>> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) >>>> at >>>> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172) >>>> at >>>> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) >>>> at >>>> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117) >>>> at >>>> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108) >>>> at >>>> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174) >>>> at >>>> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:875) >>>> at >>>> org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665) >>>> at >>>> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528) >>>> at >>>> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81) >>>> at >>>> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689) >>>> at java.lang.Thread.run(Thread.java:619) >>>> Caused by: java.lang.IllegalArgumentException: >>>> java.lang.classcastexcept...@42ae5f >>>> at sun.reflect.GeneratedMethodAccessor38.invoke(Unknown Source) >>>> at >>>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAc1cessorImpl.java:25) >>>> at java.lang.reflect.Method.invoke(Method.java:597) >>>> at >>>> org.apache.wicket.RequestListenerInterface.invoke(RequestListenerInterface.java:182) >>>> ... 26 more >>>> >>>> >>>> ------------- >>>> >>>> >>>> The problem is this I don't get more information than that, and I only >>>> get the exception once each, say... 50 times I reload the page (I mean >>>> "browser reload" = new page object). The other 49 times everything >>>> works fine. It's quite random... >>>> >>>> Any clues? >>>> >>>> >>>> Regards, >>>> Daniel. >>>> >>>> --------------------------------------------------------------------- >>>> To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org >>>> For additional commands, e-mail: users-h...@wicket.apache.org >>>> >>>> >>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org >>> For additional commands, e-mail: users-h...@wicket.apache.org >>> >>> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org >> For additional commands, e-mail: users-h...@wicket.apache.org >> >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org > For additional commands, e-mail: users-h...@wicket.apache.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org For additional commands, e-mail: users-h...@wicket.apache.org
