ItemsImporter::refresh

public ItemsImporter::refresh(FeedInterface $feed)

public function refresh(FeedInterface $feed) {
  // Store feed URL to track changes.
  $feed_url = $feed->getUrl();

  // Fetch the feed.
  try {
    $success = $this->fetcherManager->createInstance($this->config->get('fetcher'))->fetch($feed);
  }
  catch (PluginException $e) {
    $success = FALSE;
    watchdog_exception('aggregator', $e);
  }

  // Store instances in an array so we dont have to instantiate new objects.
  $processor_instances = array();
  foreach ($this->config->get('processors') as $processor) {
    try {
      $processor_instances[$processor] = $this->processorManager->createInstance($processor);
    }
    catch (PluginException $e) {
      watchdog_exception('aggregator', $e);
    }
  }

  // We store the hash of feed data in the database. When refreshing a
  // feed we compare stored hash and new hash calculated from downloaded
  // data. If both are equal we say that feed is not updated.
  $hash = hash('sha256', $feed->source_string);
  $has_new_content = $success && ($feed->getHash() != $hash);

  if ($has_new_content) {
    // Parse the feed.
    try {
      if ($this->parserManager->createInstance($this->config->get('parser'))->parse($feed)) {
        if (!$feed->getWebsiteUrl()) {
          $feed->setWebsiteUrl($feed->getUrl());
        }
        $feed->setHash($hash);
        // Update feed with parsed data.
        $feed->save();

        // Log if feed URL has changed.
        if ($feed->getUrl() != $feed_url) {
          $this->logger->notice('Updated URL for feed %title to %url.', array('%title' => $feed->label(), '%url' => $feed->getUrl()));
        }

        $this->logger->notice('There is new syndicated content from %site.', array('%site' => $feed->label()));

        // If there are items on the feed, let enabled processors process them.
        if (!empty($feed->items)) {
          foreach ($processor_instances as $instance) {
            $instance->process($feed);
          }
        }
      }
    }
    catch (PluginException $e) {
      watchdog_exception('aggregator', $e);
    }
  }

  // Processing is done, call postProcess on enabled processors.
  foreach ($processor_instances as $instance) {
    $instance->postProcess($feed);
  }

  return $has_new_content;
}