private void createRoleInput(Form<T> form) { ListMultipleChoice<UserRole> userRoles = new ListMultipleChoice<UserRole>("user.userRoles", getUserRoles(), new UserRoleRenderer()); userRoles.setMaxRows(4); userRoles.setLabel(new ResourceModel("admin.user.roles")); userRoles.setRequired(true); userRoles.add(new ValidatingFormComponentAjaxBehavior()); form.add(userRoles); form.add(new AjaxFormComponentFeedbackIndicator("rolesValidationError", userRoles)); }