[Wicket-user] ListMultipleChoice

[Kruger Jan Petter]

I’m trying to implement a page with two selection lists. The purpose is to have a control where one can move selected choices between the two lists.   With a little _javascript_ the movement of items between the lists is easy, but the problem arises when the form embedding the lists is submitted. If the Content in the lists are changed, wicket gives me a runtime exception. I guess this has something to do with the change in number of elements in the lists, and some checks against the model.  I have used a ListMulitpleChoice control like   new ListMultipleChoice("availableDomainRoles",userWeb.getAvailableDomainRoles());   I could create a class that extends ListMultipleChoice. Are there any samples doing this, or are there another approach to this that I have missed ?     [2005-06-16 14:20:20,510] ERROR [PoolThread-49] RequestCycle.onRuntimeException(561) | Unexpected runtime exception [page = null] wicket.WicketRuntimeException: Method public abstract void wicket.markup.html.form.IFormSubmitListener.onFormSubmitted() of interface IFormSubmitListener threw an exception        at wicket.protocol.http.WebRequestCycle.invokeInterface(WebRequestCycle.java:348)        at wicket.protocol.http.WebRequestCycle.invokeInterface(WebRequestCycle.java:387)        at wicket.protocol.http.WebRequestCycle.callComponentListener(WebRequestCycle.java:284)        at wicket.protocol.http.WebRequestCycle.parseRequest(WebRequestCycle.java:122)        at wicket.RequestCycle.request(RequestCycle.java:372)        at wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:221)        at wicket.protocol.http.WicketServlet.doPost(WicketServlet.java:245)        at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)        at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:358)        at org.mortbay.jetty.servlet.WebApplicationHandler.dispatch(WebApplicationHandler.java:294)        at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:567)        at org.mortbay.http.HttpContext.handle(HttpContext.java:1807)        at org.mortbay.jetty.servlet.WebApplicationContext.handle(WebApplicationContext.java:525)        at org.mortbay.http.HttpContext.handle(HttpContext.java:1757)        at org.mortbay.http.HttpServer.service(HttpServer.java:879)        at org.mortbay.http.HttpConnection.service(HttpConnection.java:790)        at org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:961)        at org.mortbay.http.HttpConnection.handle(HttpConnection.java:807)        at org.mortbay.http.SocketListener.handleConnection(SocketListener.java:218)        at org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:300)        at org.mortbay.util.ThreadPool$PoolThread.run(ThreadPool.java:511) Caused by: java.lang.reflect.InvocationTargetException        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)        at java.lang.reflect.Method.invoke(Method.java:324)        at wicket.protocol.http.WebRequestCycle.invokeInterface(WebRequestCycle.java:339)        ... 21 more Caused by: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0        at java.util.ArrayList.RangeCheck(ArrayList.java:507)        at java.util.ArrayList.get(ArrayList.java:324)        at wicket.markup.html.form.model.ChoiceList.get(ChoiceList.java:188)        at wicket.markup.html.form.model.ChoiceList.choiceForId(ChoiceList.java:154)        at wicket.markup.html.form.ListMultipleChoice.updateModel(ListMultipleChoice.java:188)        at wicket.markup.html.form.Form$12.formComponent(Form.java:546)        at wicket.markup.html.form.Form$6.component(Form.java:411)        at wicket.MarkupContainer.visitChildren(MarkupContainer.java:499)        at wicket.markup.html.form.Form.visitFormComponents(Form.java:407)        at wicket.markup.html.form.Form.updateFormComponentModels(Form.java:538)        at wicket.markup.html.form.Form.validate(Form.java:386)        at wicket.markup.html.form.Form.onValidate(Form.java:337)        at wicket.markup.html.form.Form.onFormSubmitted(Form.java:223)        ... 26 more     Jan-Petter ::-Q