wicket 6: calling javascript function after page load

Question

This seems so simple, yet I cannot find an example of how to call javascript function from wicket, after the page is loaded (on page that extends WebPage). Can anyone give example on how to go that?

Monograph

as noted in the question, the version of wicket is 6 – Monograph

Answer 1

You can have javascript do that for you

window.onload = function () {
// do stuff here
}

If you need parameters from your wicket page in the javascript function you can override renderHead and add the function there:

@Override
public void renderHead(IHeaderResponse response)
{
    super.renderHead(response);
    String bar = "something";
    response.render(JavaScriptHeaderItem.forScript("window.onload = function () {var foo='" + bar + "'}"));
    // or
    response.render(OnDomReadyHeaderItem.forScript("functionToCall(" + bar + ");") ;
}

Cutaneous

tried "response.render(OnDomReadyHeaderItem.forScript("testAlert();")) ;" - works for me. thanks! – Monograph

Answer 2

Yet another way to do that is to create AjaxEventBehavior as follows and add it to your page.

AjaxEventBehavior event = new AjaxEventBehavior("onload") {
    @Override
    protected void onEvent(final AjaxRequestTarget target) {
        // do stuff here
        target.appendJavaScript("alert('onload');");
    }
}
add(event);

Ninefold

Can you add this to a component or does it have to be the page? Doesn't seem to fire when adding to a component... – Accepted

appendJavaScript(), appends the mentioned function or the piece of the JS. When used in a Wicket function which is called repeatedly, the JS code gets executed multiple times and linearly increases. – Overview

This solution in Wicket 8 seems not to work anymore. – Trombidiasis

Is there alternative way for Wicket 8? @andpat – Kayekayla