Feeds source источник для mapping

/**
 * Implements hook_feeds_parser_sources_alter();
 */
function ft_feeds_parser_sources_alter(&$sources, $content_type) {
  $sources['feeds_original_url'] = array(
    'name' => t('Feed source url'),
    'description' => t('Feed start url.'),
    'callback' => 'ft_get_feeds_original_url',
  );
}

function ft_get_feeds_original_url(FeedsSource $source, FeedsParserResult $result, $key) {
  $config = $source->getConfig();
  $fetcher_class_name = get_class($source->importer()->fetcher);
  $url = $config[$fetcher_class_name]['source'];

  return $url;
}