Wicket AjaxRequestTarget of jQuery callback does not Component

Question

I'm trying to implement an jQuery AJAX callback to receive an event of a third party JavaScript library.

And it nearly works! :)

The jQuery AJAX post is receiver at the server side. The callback URL is generated by an AbstractDefaultAjaxBehavior, which has been added to a Panel. On respond method of the Behavior I added a child component of the Panel to the AjaxRequestTarget. But this does not repaint the component. No exception is thrown, output oft markupId is set.

Any idea? Any idea where I can find a wicket component doing something similar in GitHub, etc.

Answer 1

My solution based on the comments above. Simple Label to update via AjaxCallback:

    public class HomePage extends WebPage {

        private static final long serialVersionUID = 1L;

        private String value = "Hello World";

        public HomePage(final PageParameters parameters) {
            super(parameters);

            final Label label = new Label("label", new PropertyModel(HomePage.this, "value"));
            label.setOutputMarkupId(true);
            add(label);

            label.add(new DemoCallback(){
                @Override
                protected void onCallback(String fromClient, AjaxRequestTarget target) {
                    value = fromClient;
                    target.add(label);
                }
            }); 
        }
    }

The behavior which render the callback:

    public class DemoCallback extends AbstractDefaultAjaxBehavior {

        @Override
        public void renderHead(Component component, IHeaderResponse response) {
            super.renderHead(component, response);

            StringBuffer script = new StringBuffer();
            script.append("alert('Callback will follow!');\n");
            script.append("var dataForServer='From client with love.';\n");
            script.append(getCallbackFunctionBody(CallbackParameter
                    .explicit("dataForServer")));

            response.render(OnEventHeaderItem.forScript(
                    "'" + component.getMarkupId() + "'", "click", script.toString()));
        }

        @Override
        protected void updateAjaxAttributes(AjaxRequestAttributes attributes) {
            super.updateAjaxAttributes(attributes);
            attributes.setMethod(Method.POST);
        }

        @Override
        protected void respond(AjaxRequestTarget target) {
            StringValue parameterValue = RequestCycle.get().getRequest()
                    .getPostParameters().getParameterValue("dataForServer");
            onCallback(parameterValue.toString(), target);
        }

        protected void onCallback(String fromClient, AjaxRequestTarget target) {
            // overide to handle callback
        }
    }

What wicket do render in the head-section:

    Wicket.Event.add('label1', "click", function(event) { 
        alert('Callback will follow!');
        var dataForServer='From client with love.';
        var attrs = {"u":"./?0-2.IBehaviorListener.0-label","c":"label1","m":"POST"};
        var params = {'dataForServer': dataForServer};
        attrs.ep = params;
        Wicket.Ajax.ajax(attrs);
    ;});