palette + wizard + validation not empty + a particular item

[Fernando Wermus <fe...@gmail.com>]

Hi all,
    I need to validate a palette which is in a wizardStep. The validation
consists of being not empty either of having a spec item. The model has the
selected item at the begining. I got an Nullpointer exception when I add the
onchange behavior. The idea is to keep up to date the palette, otherwise I
wouldn't see any changes in the palette. What's wrong?

(MyWizard.java)
...
        step.add(new IFormValidator(){
            private static final long serialVersionUID =
8174199867825424322L;

            public FormComponent[] getDependentFormComponents() {
                return null;
            }

            public void validate(Form form) {

                if (modelo.getCandidatos().isEmpty() ||
!modelo.getCandidatos().contains(SesionMisPartidos.getUsuario())){
                    form.error("debe seleccionar mas de un candidato y debes
estar en la lista");
                }
        }});
        stepCandidatos.getPalette().getRecorderComponent().add(new
AjaxFormComponentUpdatingBehavior("onchange") {
            private static final long serialVersionUID = 1L;

            @Override
            protected void onUpdate(AjaxRequestTarget target) {
            }});

I got a nullpointer exception in
stepCandidatos.getPalette().getRecorderComponent().add(new
AjaxFormComponentUpdatingBehavior("onchange") {

I am working with wicket 1.3.0
-- 
Fernando Wermus.

www.linkedin.com/in/fernandowermus
http://mientretiempo.blogspot.com/