ArticleTypeField::setFilter PHP Method

    public function setFilter($p_filter)
    {
        $this->m_filterOut = (bool) ('' . $p_filter);
        if (!$this->getType()) {
            $filter_db_value = (int) $this->m_filterOut;
            $this->setProperty('field_type_param', 'filter=' . $filter_db_value);
            return true;
        }
        return false;
    }

 /**
  * Action for setting article type filtering.
  *
  * @return bool
  **/
 public static function SetTypeFilter($p_article_type, $p_filter_value)
 {
     $p_filter_value = (bool) trim('' . $p_filter_value);
     $field = new ArticleTypeField($p_article_type, 'NULL');
     if (!$field->exists()) {
         return getGS('No such article type');
     }
     $res = $field->setFilter($p_filter_value);
     if (!$res) {
         return getGS('Filter not saved');
     }
     return getGS('Filter saved');
 }