Modal Window or confirm box in Form.onSubmit

In Form.onS开发者_StackOverflow中文版ubmit can I add a SimpleAttributeModifier to that form? Actually I have a situation where the onSubmit method of the form look like this:

@Override
public void onSubmit() {
    //some code
    if (some_condition) {
        //here I want to show Javascript confirm box or wicket modal window
        //but I can not get any AjaxRequestTarget here to show that modal
        add(new SimpleAttributeModifier("onSubmit", "return confirm('confirm msg')"));
    }
    //some code
}        

It is not working. Is there any way to achieve this? Thank you.

What you're trying will definitely not work, as the onSubmit() method is not called in time. It is a server-side method called when the form is submitted. In order to show a confirm dialogue, you want some javascript executed on the client before the form is sent back from the client to the server.

You need the attachment of javascript to happen when the html is rendered, so that it's there to be called when the user clicks the submit button.

It can of course be done. I don't have my own code for it handy, but I think this example should get you pointed in the right direction.