How display result of form every x second

Question

I have some form which searching result from db. How can I display results from db automatically every x second ? This means submit button every x second. All I found about refreshing is this class:

add(new AjaxSelfUpdatingTimerBehavior(Duration.seconds(10)) {
    private static final long serialVersionUID = 1;       
    });

which just refresh page not submit form. Then I wanna inspire from wicket example pages: http://www.wicket-library.com/wicket-examples/ajax/clock?1 but when I click to source code I just see urls which just return: Internal error

UPDATE:

I try to call simple javascript and then submit form from js:

    add(new AjaxSelfUpdatingTimerBehavior(Duration.seconds(10)) {
        private static final long serialVersionUID = 1L;

        @Override
        protected void onPostProcessTarget(AjaxRequestTarget target) {
            target.appendJavaScript("alert('hello');");
        }

    });

but with no success

Answer 1

You'll need a combination of AbstractAjaxTimerBehaviour to raise an event that triggers an AjaxFormSubmittingBehaviour. I didn't try this but from my wicket experience and the JavaDocs of both behaviours, it should work.

Since there seems to be the need for some demo code...

Disclaimer: This was thrown together in a couple of minutes by Copy'n'Pasting from both mentioned classes. So this isn't good code, tested code or anything I'd put into production without having a solid look at it. But it seems to work.

First you need the combined Behavior:

public abstract class AjaxTimerFormSubmitBehavior extends AbstractAjaxTimerBehavior {

    /**
     * should never be accessed directly (thus the __ cause its overkill to
     * create a super class), instead always use #getForm()
     */
    private Form<?> __form;

    private boolean defaultProcessing = true;

    /**
     * @param updateInterval
     */
    public AjaxTimerFormSubmitBehavior(Duration updateInterval) {
        this(null, updateInterval);
    }

    public AjaxTimerFormSubmitBehavior(Form<?> form, Duration updateInterval) {
        super(updateInterval);
        __form = form;

        if (form != null) {
            form.setOutputMarkupId(true);
        }
    }

    @Override
    protected void onTimer(final AjaxRequestTarget target) {
        getForm().getRootForm().onFormSubmitted(new IFormSubmitter() {
            public Form<?> getForm() {
                return AjaxTimerFormSubmitBehavior.this.getForm();
            }

            public boolean getDefaultFormProcessing() {
                return AjaxTimerFormSubmitBehavior.this.getDefaultProcessing();
            }

            public void onSubmit() {
                AjaxTimerFormSubmitBehavior.this.onSubmit(target);
            }

            public void onError() {
                AjaxTimerFormSubmitBehavior.this.onError(target);
            }
        });
    }

    /**
     * @return Form that will be submitted by this behavior
     */
    public final Form<?> getForm() {
        if (__form == null) {
            __form = findForm();

            if (__form == null) {
                throw new IllegalStateException(
                        "form was not specified in the constructor and cannot "
                                + "be found in the hierarchy of the component this behavior "
                                + "is attached to: Component="
                                + getComponent().toString(false));
            }
        }
        return __form;
    }

    /**
     * @see Button#getDefaultFormProcessing()
     *
     * @return {@code true} for default processing
     */
    public boolean getDefaultProcessing() {
        return defaultProcessing;
    }

    /**
     * Finds form that will be submitted
     *
     * @return form to submit or {@code null} if none found
     */
    protected Form<?> findForm() {
        // try to find form in the hierarchy of owning component
        Component component = getComponent();
        if (component instanceof Form<?>) {
            return (Form<?>) component;
        } else {
            return component.findParent(Form.class);
        }
    }

    /**
     * Listener method that is invoked after the form has been submitted and
     * processed without errors
     *
     * @param target
     */
    protected abstract void onSubmit(AjaxRequestTarget target);

    /**
     * Listener method invoked when the form has been processed and errors
     * occurred
     *
     * @param target
     */
    protected abstract void onError(AjaxRequestTarget target);

}

And then you've got to use it

public class HomePage extends WebPage {
    private static final long serialVersionUID = 1L;

    private Integer counter = 0;

    public HomePage(final PageParameters parameters) {
        final Label label = new Label("counter", new PropertyModel<Integer>(this, "counter"));
        label.setOutputMarkupId(true);
        add(label);
        Form form = new Form("form");
        form.add(new AjaxTimerFormSubmitBehavior(form, Duration.seconds(10)) {

            @Override
            protected void onSubmit(AjaxRequestTarget target) {
                counter++;
                target.add(label);
            }

            @Override
            protected void onError(AjaxRequestTarget target) {
                // TODO Auto-generated method stub

            }
        });
        add(form);
    }

    public Integer getCounter() {
        return counter;
    }

    public void setCounter(Integer counter) {
        this.counter = counter;
    }
}

I hope that'll give you an idea...

Here is a small demo war-file. Just download, toss at your favorite Application Container and watch what it does. It contains the sources too.

Answer 2

To set an interval an run some code regularly, you could do this using JQuery:

$(document).ready(function(){
    //ajax code here
    myVar = setInterval(someCode, 10000);
});

That what you after?

EDIT

Just realised... set Interval isn't actually a JQuery function.

//use this to stop it    
clearInterval(myVar);

Answer 3

I think you did the right things, I think you attached the behavior to a component that doesn't change itself. You will need to write the update logic in the onPostProcessTarget method and add the component you want to refresh to the ajaxRequestTarget. Have a look at the network tab of Firebug or Chrome to see if the behavior triggers a call to the server.

If it's not the case, it might be that the precondition of the script fails (markup id change could do this)