public function __construct()
 {
     $required_fields = array('title', 'alias', 'introtext', 'fulltext', 'state', 'catid', 'created', 'created_by', 'created_by_alias', 'modified', 'modified_by', 'publish_up', 'publish_down', 'version', 'access');
     $optional_fields = array('attribs', 'mask', 'hits', 'metadata', 'metadesc', 'metakey', 'title_alias', 'version');
     $field_default = array('language' => '*', 'state' => 1, 'access' => 1);
     $extra_fields = array('category_title', 'created_by_name');
     parent::__construct($required_fields, $optional_fields, $field_default, $extra_fields);
 }
 public function __construct()
 {
     $required_fields = array('id', 'filename', 'filename_sys', 'file_type', 'file_size', 'url', 'uri_type', 'url_valid', 'url_relative', 'display_name', 'description', 'icon_filename', 'access', 'state', 'user_field_1', 'user_field_2', 'user_field_3', 'parent_type', 'parent_entity', 'parent_id', 'parent_title', 'created', 'created_by', 'created_by_username', 'modified', 'modified_by', 'modified_by_username', 'download_count');
     $optional_fields = array();
     $field_default = array();
     $extra_fields = array('parent_title', 'created_by_username', 'modified_by_username');
     parent::__construct($required_fields, $optional_fields, $field_default, $extra_fields);
 }