How to handle changes in a form with a model-update using Wicket and AJAX - ajax

Question

I have a form with many input-fields and need to handle a change to any of those input-fields; so I add a AjaxEventBehavior to the form, like:
Form<MyX> myForm = new Form<>("X", getModel());
myForm.add(new AjaxEventBehavior("onchange") {
#Override
protected void onEvent(AjaxRequestTarget target) {
handleFormChange(...);
}
});
The method handleFormChange gets called everytime I change some content in the input-fields of the form. But the model is not getting updated with the new value of the changed input-field of the form.
How can I get thoose model-updates? I tried AjaxFormComponentUpdatingBehavior. It updates the model, but I cannot use it for forms, just for FormComponents.
Does anybody has an ideas how to handle that? TIA!

Answer 1

With AjaxFormSubmitBehavior you can submit the whole form on each change.

Answer 2

First for on change use the dedicated OnChangeAjaxBehavior.
Then you can use the Iterator of the form to get all children and add then add the OnChangeAjaxBehavior to all FormComponents which will call your handleFormChange() on every change like this:
for (Iterator it = form.iterator(); it.hasNext();) {
Object o = it.next();
if (o instanceof FormComponent) {
((FormComponent) o).add(new OnChangeAjaxBehavior() {
#Override
protected void onUpdate(AjaxRequestTarget target) {
handleFormChange(...);
}
});
}
}