Cannot set model for Listbox from EventQueue.subscribe method

asked 2016-07-15 10:35:08 +0800

realcandy
1 ● 1

updated 2016-07-15 10:38:34 +0800

Cannot set model for listbox from EventQueue.subscribe method. First time, it works fine, but when i go to another page and returns it shows me weird NPE

java.lang.NullPointerException

at org.zkoss.zk.ui.AbstractComponent.getAttachedUiEngine(AbstractComponent.java:387) at org.zkoss.zk.ui.AbstractComponent.smartUpdate(AbstractComponent.java:1487) at org.zkoss.zk.ui.AbstractComponent.smartUpdate(AbstractComponent.java:1462) at org.zkoss.zk.ui.AbstractComponent.smartUpdate(AbstractComponent.java:1495) at org.zkoss.zul.Listbox.resetDataLoader(Listbox.java:2982) at org.zkoss.zul.Listbox.setModel(Listbox.java:2377) at com.is.sdbooks.controller.ComposerTest.refreshModel(ComposerTest.java:169) at com.is.sdbooks.controller.ComposerTest.onDoubleClick$dataGrid(ComposerTest.java:180) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.zkoss.zk.ui.event.GenericEventListener.onEvent(GenericEventListener.java:81) at org.zkoss.zk.ui.impl.EventProcessor.process0(EventProcessor.java:192) at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:138) at org.zkoss.zk.ui.event.Events.sendEvent(Events.java:306) at org.zkoss.zk.ui.event.Events.sendEvent(Events.java:329) at org.zkoss.zk.ui.AbstractComponent$ForwardListener.onEvent(AbstractComponent.java:3052) at org.zkoss.zk.ui.impl.EventProcessor.process0(EventProcessor.java:192) at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:138) at org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1626) at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1410) at org.zkoss.zk.ui.impl.UiEngineImpl.execUpdate(UiEngineImpl.java:1134) at org.zkoss.zk.au.http.DHtmlUpdateServlet.process(DHtmlUpdateServlet.java:562) at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:457) at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:465) at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) at java.lang.Thread.run(Unknown Source)

Here i publish to EventQueue from another page's controller. By the way, this page is included with include tag to my main .zul file.

eq = EventQueues.lookup("CLIENTS", EventQueues.DESKTOP, true);
                    eq.publish(new Event("onClick", null, customer));

Here I'm subscribing in my main controller to EventQueue and trying to set model for the listbox

    eq = EventQueues.lookup("CLIENTS", EventQueues.DESKTOP, true);

    eq.subscribe(new EventListener() {
        public void onEvent(Event event) throws Exception {

            if (!Executions.getCurrent().getDesktop().isAlive()) {
                eq.unsubscribe(this);
                return;
            }

            Customer customer = (Customer) event.getData();

            if (customer != null){

                id = customer.getId();

                crm_div.setVisible(false); // Listbox from another page 
                                               // When a user clicks it, dataListBox should be rendered                           
                dataListbox.setVisible(true);   
                dataListbox.setModel(new DataListboxModel());           

           }
           else{
               alert("No client");
           }                              
        }
    });