protected function getDirectoryParsers()
    {
        $parsers = array();
        $models = $this->getPortableModelRegistry()->getModels();
        foreach ($models as $key => $model) {
            if ($model->getDirectoryParser() instanceof PortableElementDirectoryParser) {
                $parsers[] = $model->getDirectoryParser();
            } else {
                \common_Logger::w('Invalid DirectoryParser for model '.$key);
            }
        }
        return $parsers;
    }