Wicket dummy form field

I try to make form for user to register using Wicket. I got user POJO and wicket form - this needs to have "repeat password" field which should be in no way connected to User object. But how can I do this? I

public class RegisterForm extends Form<User> {

private static final long serialVersionUID = -9071906666130179515L;

public RegisterForm(String id) {
    super(id, new CompoundPropertyModel<User>(new User()));

    PasswordTextField pass  = new PasswordTextField("password");
    pass.setType(String.class);

    PasswordTextField pass2 = new PasswordTextField("password2");
    pass2.setType(String.class);
    pass2.setDefaultModelObject("");

    add(new EqualPasswordInputValidator(pass, pass2));

   开发者_开发知识库 add(new TextField<String>("login")
                .setType(String.class)
                .setRequired(true)
                .add(new PatternValidator("[a-z0-9]*")));

    add(new TextField<String>("email")
                 .setType(String.class)
                 .add(EmailAddressValidator.getInstance()));

    add(pass);

    add(pass2);
}

But i get

java.lang.IllegalStateException: Attempt to set model object on null model of component:

or that User model has no password2 related methods. How to handle such a case?

This should do it:

PasswordTextField pass2 = new PasswordTextField("password2", Model.of(""));

Explanation: CompoundPropertyModel associates nested form elements with the parent model (component name foo is mapped to the bean.foo property of the parent model). You can overwrite this behavior by assigning a different model to the child component.

I would have used a property in the form and a PropertyModel. This way I would have access to the field throught the getPassword2() method.

public class RegisterForm extends Form<User> {

private static final long serialVersionUID = -9071906666130179515L;

// password2 Property
protected String password2 = "";

public String getPassword2() {
    return password2;
}

public void setPassword2(String password2) {
    this.password2 = password2;
}
// end password2 Property

public RegisterForm(String id) {
    super(id, new CompoundPropertyModel<User>(new User()));

    PasswordTextField pass  = new PasswordTextField("password");
    pass.setType(String.class);

    // add new PropertyModel
    PasswordTextField pass2 = new PasswordTextField("password2", new PropertyModel<String>(this, "password2"));

    add(new EqualPasswordInputValidator(pass, pass2));

    add(new TextField<String>("login")
                .setType(String.class)
                .setRequired(true)
                .add(new PatternValidator("[a-z0-9]*")));

    add(new TextField<String>("email")
                 .setType(String.class)
                 .add(EmailAddressValidator.getInstance()));

    add(pass);

    add(pass2);
}