Wie kann man in symfony 1.3 einfach alle Formular Pflichtfelder kennzeichnen?

public static function listenToPostConfigure($event)
{
  $form            = $event->getSubject();
  $widgetSchema    = $form->getWidgetSchema();
  $validatorSchema = $form->getValidatorSchema();
 
  $fields = $form->getFormFieldSchema()->getWidget()->getFields();
  foreach ($fields as $key => $object)
  {
    $label = $form->getFormFieldSchema()->offsetGet($key)->renderLabelName();
    if (isset($validatorSchema[$key]) and $validatorSchema[$key]->getOption('required') == true)
    {
      $title  = $key . '_field_is_required';
      $label .= '<sup>getFormFormatter()->translate($title) . '">*</sup>';
    }
    $widgetSchema->setLabel($key, $label);
  }
}

$dispatcher = $this->getEventDispatcher();
$dispatcher->connect('form.post_configure', array('BaseForm', 'listenToPostConfigure'));