protected function listeners()
{
parent::listeners();
Event::listen($this, Event::BEFORE_UPDATE_FORM_PARSE, array($this, 'handle_widget_before_form_parse'));
Event::listen($this, Event::BEFORE_CREATE, array($this, 'handle_widget_before_update'));
Event::listen($this, Event::BEFORE_UPDATE, array($this, 'handle_widget_before_update'));
}