Implementing javascript events to Wicket

Question

I'm new to ria-development and working with the Ajax Slider example. I can't figure out how to work with javascript events. Here in the example the onValueChanged-event is preimplemented. How do I implement say onchange- or onSlider-event?

All help greatly appreciated!

public abstract class AjaxSlider extends WebMarkupContainer {

    private static final long serialVersionUID = 1L;

    public AjaxSlider(String id) {
            super(id);
            super.setOutputMarkupId(true);
    }
    public JQUIComponentBehaivor<SliderOptions> getSlideBehaviors() {
        List behaviors = getBehaviors();
        for(Object behavior : behaviors){
            if(behavior instanceof SliderBehavior)
                        return (SliderBehavior) behavior;
        }
        return null;
    }


    public abstract void onValueChanged(AjaxRequestTarget target,
                    int newValue);

    @Override
    protected void onInitialize() {
            super.onInitialize();
            AbstractDefaultAjaxBehavior ajaxBehavior =
                new AbstractDefaultAjaxBehavior() {
                    private static final long serialVersionUID = 1L;

                    @Override
                    protected void respond(AjaxRequestTarget target) {
                            String sliderValue = RequestCycle.get().getRequest()
                                            .getParameter("sv");
                            if (Utils.isNotBlank(sliderValue)) {
                                    onValueChanged(target, Integer.valueOf(sliderValue));
                            }
                    }
            };
            super.add(ajaxBehavior);
            super.add(new SliderBehavior(new SliderOptions()
                            .changeEvent(wicketAjaxGet(
                                            ajaxBehavior,
                                            new MapBuilder<String, Object>().add("sv",
                                                            js("ui.value")).build()))));
    }

}

Answer 1

The example you gave adds an event handler for the change event. What this event handler does is issueing a GET request to the ajaxBehaviordefined above. The behavior then extracts the slider value from the GET parameters and calls onValueChanged.

You can add another event handler just like this to SliderOptions. For instance:

.slideEvent(
    wicketAjaxGet(ajaxBehavior,
                  new MapBuilder<String, Object>()
                  .add("sv",  js("ui.value")).build()))));

This handler should call the ajax behavior any time the user moves the slider.