public static function search_categories($text, $phrase, $ordering, $limit)
 {
     global $CFG, $DB;
     $params = self::validate_parameters(self::search_categories_parameters(), array('text' => $text, 'phrase' => $phrase, 'ordering' => $ordering, 'limit' => $limit));
     $auth = new auth_plugin_joomdle();
     $return = $auth->search_categories($text, $phrase, $ordering, $limit);
     return $return;
 }