aggregator.module

<?php
// $Id$

/**
 * @file
 * Used to aggregate syndicated content (RSS, RDF, and Atom).
 */

/**
 * Implementation of hook_help().
 */
function aggregator_help($path, $arg) {
  switch ($path) {
    case 'admin/help#aggregator':
      $output = '<p>'. t('The news aggregator is a powerful on-site RSS syndicator/news reader that can gather fresh content from news sites and weblogs around the web.') .'</p>';
      $output .= '<p>'. t('Users can view the latest news chronologically in the <a href="@aggregator">main news aggregator display</a> or by <a href="@aggregator-sources">source</a>. Administrators can add, edit and delete feeds and choose how often to check for newly updated news for each individual feed. Administrators can also tag individual feeds with categories, offering selective grouping of some feeds into separate displays. Listings of the latest news for individual sources or categorized sources can be enabled as blocks for display in the sidebar through the <a href="@admin-block">block administration page</a>. The news aggregator requires cron to check for the latest news from the sites to which you have subscribed. Drupal also provides a <a href="@aggregator-opml">machine-readable OPML file</a> of all of your subscribed feeds.', array('@aggregator' => url('aggregator'), '@aggregator-sources' => url('aggregator/sources'), '@admin-block' => url('admin/build/block'), '@aggregator-opml' => url('aggregator/opml'))) .'</p>';
      $output .= '<p>'. t('For more information please read the configuration and customization handbook <a href="@aggregator">Aggregator page</a>.', array('@aggregator' => 'http://drupal.org/handbook/modules/aggregator/')) .'</p>';
      return $output;
    case 'admin/content/aggregator':
      return '<p>'. t('Thousands of sites (particularly news sites and weblogs) publish their latest headlines and/or stories in a machine-readable format so that other sites can easily link to them. This content is usually in the form of an <a href="http://blogs.law.harvard.edu/tech/rss">RSS</a> feed (which is an XML-based syndication standard). To display the feed or category in a block you must decide how many items to show by editing the feed or block and turning on the <a href="@block">feed\'s block</a>.', array('@block' => url('admin/build/block'))) .'</p>';
    case 'admin/content/aggregator/add/feed':
      return '<p>'. t('Add a site that has an RSS/RDF/Atom feed. The URL is the full path to the feed file. For the feed to update automatically you must run "cron.php" on a regular basis. If you already have a feed with the URL you are planning to use, the system will not accept another feed with the same URL.') .'</p>';
    case 'admin/content/aggregator/add/category':
      return '<p>'. t('Categories provide a way to group items from different news feeds together. Each news category has its own feed page and block. For example, you could tag various sport-related feeds as belonging to a category called <em>Sports</em>. News items can be added to a category automatically by setting a feed to automatically place its item into that category, or by using the categorize items link in any listing of news items.') .'</p>';
  }
}

/**
 * Implementation of hook_theme()
 */
function aggregator_theme() {
  return array(
    'aggregator_wrapper' => array(
      'arguments' => array('content' => NULL),
      'file' => 'aggregator.pages.inc',
      'template' => 'aggregator-wrapper',
    ),
    'aggregator_categorize_items' => array(
      'arguments' => array('form' => NULL),
      'file' => 'aggregator.pages.inc',
    ),
    'aggregator_feed_source' => array(
      'arguments' => array('feed' => NULL),
      'file' => 'aggregator.pages.inc',
      'template' => 'aggregator-feed-source',
    ),
    'aggregator_block_item' => array(
      'arguments' => array('item' => NULL, 'feed' => 0),
    ),
    'aggregator_summary_items' => array(
      'arguments' => array('summary_items' => NULL, 'source' => NULL),
      'file' => 'aggregator.pages.inc',
      'template' => 'aggregator-summary-items',
    ),
    'aggregator_summary_item' => array(
      'arguments' => array('item' => NULL),
      'file' => 'aggregator.pages.inc',
      'template' => 'aggregator-summary-item',
    ),
    'aggregator_item' => array(
      'arguments' => array('item' => NULL),
      'file' => 'aggregator.pages.inc',
      'template' => 'aggregator-item',
    ),
    'aggregator_page_opml' => array(
      'arguments' => array('feeds' => NULL),
      'file' => 'aggregator.pages.inc',
    ),
    'aggregator_page_rss' => array(
      'arguments' => array('feeds' => NULL, 'category' => NULL),
      'file' => 'aggregator.pages.inc',
    ),
  );
}

/**
 * Implementation of hook_menu().
 */
function aggregator_menu() {
  $items['admin/content/aggregator'] = array(
    'title' => 'News aggregator',
    'description' => "Configure which content your site aggregates from other sites, how often it polls them, and how they're categorized.",
    'page callback' => 'aggregator_admin_overview',
    'access arguments' => array('administer news feeds'),
    'file' => 'aggregator.admin.inc',
  );
  $items['admin/content/aggregator/add/feed'] = array(
    'title' => 'Add feed',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('aggregator_form_feed'),
    'access arguments' => array('administer news feeds'),
    'type' => MENU_LOCAL_TASK,
    'parent' => 'admin/content/aggregator',
    'file' => 'aggregator.admin.inc',
  );
  $items['admin/content/aggregator/add/category'] = array(
    'title' => 'Add category',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('aggregator_form_category'),
    'access arguments' => array('administer news feeds'),
    'type' => MENU_LOCAL_TASK,
    'parent' => 'admin/content/aggregator',
    'file' => 'aggregator.admin.inc',
  );
  $items['admin/content/aggregator/remove/%aggregator_feed'] = array(
    'title' => 'Remove items',
    'page callback' => 'aggregator_admin_remove_feed',
    'page arguments' => array(4),
    'access arguments' => array('administer news feeds'),
    'type' => MENU_CALLBACK,
    'file' => 'aggregator.admin.inc',
  );
  $items['admin/content/aggregator/update/%aggregator_feed'] = array(
    'title' => 'Update items',
    'page callback' => 'aggregator_admin_refresh_feed',
    'page arguments' => array(4),
    'access arguments' => array('administer news feeds'),
    'type' => MENU_CALLBACK,
    'file' => 'aggregator.admin.inc',
  );
  $items['admin/content/aggregator/list'] = array(
    'title' => 'List',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10,
  );
  $items['admin/content/aggregator/settings'] = array(
    'title' => 'Settings',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('aggregator_admin_settings'),
    'type' => MENU_LOCAL_TASK,
    'weight' => 10,
    'access arguments' => array('administer news feeds'),
    'file' => 'aggregator.admin.inc',
  );
  $items['aggregator'] = array(
    'title' => 'News aggregator',
    'page callback' => 'aggregator_page_last',
    'access arguments' => array('access news feeds'),
    'weight' => 5,
    'file' => 'aggregator.pages.inc',
  );
  $items['aggregator/sources'] = array(
    'title' => 'Sources',
    'page callback' => 'aggregator_page_sources',
    'access arguments' => array('access news feeds'),
    'file' => 'aggregator.pages.inc',
  );
  $items['aggregator/categories'] = array(
    'title' => 'Categories',
    'page callback' => 'aggregator_page_categories',
    'access callback' => '_aggregator_has_categories',
    'file' => 'aggregator.pages.inc',
  );
  $items['aggregator/rss'] = array(
    'title' => 'RSS feed',
    'page callback' => 'aggregator_page_rss',
    'access arguments' => array('access news feeds'),
    'type' => MENU_CALLBACK,
    'file' => 'aggregator.pages.inc',
  );
  $items['aggregator/opml'] = array(
    'title' => 'OPML feed',
    'page callback' => 'aggregator_page_opml',
    'access arguments' => array('access news feeds'),
    'type' => MENU_CALLBACK,
    'file' => 'aggregator.pages.inc',
  );
  $items['aggregator/categories/%aggregator_category'] = array(
    'title callback' => '_aggregator_category_title',
    'title arguments' => array(2),
    'page callback' => 'aggregator_page_category',
    'page arguments' => array(2),
    'access callback' => 'user_access',
    'access arguments' => array('access news feeds'),
    'file' => 'aggregator.pages.inc',
  );
  $items['aggregator/categories/%aggregator_category/view'] = array(
    'title' => 'View',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10,
  );
  $items['aggregator/categories/%aggregator_category/categorize'] = array(
    'title' => 'Categorize',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('aggregator_page_category', 2),
    'access arguments' => array('administer news feeds'),
    'type' => MENU_LOCAL_TASK,
    'file' => 'aggregator.pages.inc',
  );
  $items['aggregator/categories/%aggregator_category/configure'] = array(
    'title' => 'Configure',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('aggregator_form_category', 2),
    'access arguments' => array('administer news feeds'),
    'type' => MENU_LOCAL_TASK,
    'weight' => 1,
    'file' => 'aggregator.admin.inc',
  );
  $items['aggregator/sources/%aggregator_feed'] = array(
    'page callback' => 'aggregator_page_source',
    'page arguments' => array(2),
    'type' => MENU_CALLBACK,
    'file' => 'aggregator.pages.inc',
  );
  $items['aggregator/sources/%aggregator_feed/view'] = array(
    'title' => 'View',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10,
  );
  $items['aggregator/sources/%aggregator_feed/categorize'] = array(
    'title' => 'Categorize',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('aggregator_page_source', 2),
    'access arguments' => array('administer news feeds'),
    'type' => MENU_LOCAL_TASK,
    'file' => 'aggregator.pages.inc',
  );
  $items['aggregator/sources/%aggregator_feed/configure'] = array(
    'title' => 'Configure',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('aggregator_form_feed', 2),
    'access arguments' => array('administer news feeds'),
    'type' => MENU_LOCAL_TASK,
    'weight' => 1,
    'file' => 'aggregator.admin.inc',
  );
  $items['admin/content/aggregator/edit/feed/%aggregator_feed'] = array(
    'title' => 'Edit feed',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('aggregator_form_feed', 5),
    'access arguments' => array('administer news feeds'),
    'type' => MENU_CALLBACK,
    'file' => 'aggregator.admin.inc',
  );
  $items['admin/content/aggregator/edit/category/%aggregator_category'] = array(
    'title' => 'Edit category',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('aggregator_form_category', 5),
    'access arguments' => array('administer news feeds'),
    'type' => MENU_CALLBACK,
    'file' => 'aggregator.admin.inc',
  );

  return $items;
}

function _aggregator_category_title($category) {
  return $category['title'];
}

function aggregator_init() {
  drupal_add_css(drupal_get_path('module', 'aggregator') .'/aggregator.css');
}

function _aggregator_has_categories() {
  return user_access('access news feeds') && db_result(db_query('SELECT COUNT(*) FROM {aggregator_category}'));
}



/**
 * Implementation of hook_perm().
 */
function aggregator_perm() {
  return array('administer news feeds', 'access news feeds');
}

/**
 * Implementation of hook_cron().
 *
 * Checks news feeds for updates once their refresh interval has elapsed.
 */
function aggregator_cron() {
  $result = db_query('SELECT * FROM {aggregator_feed} WHERE checked + refresh < %d', time());
  while ($feed = db_fetch_array($result)) {
    aggregator_refresh($feed);
  }
}

/**
 * Implementation of hook_block().
 *
 * Generates blocks for the latest news items in each category and feed.
 */
function aggregator_block($op = 'list', $delta = 0, $edit = array()) {
  if (user_access('access news feeds')) {
    if ($op == 'list') {
      $result = db_query('SELECT cid, title FROM {aggregator_category} ORDER BY title');
      while ($category = db_fetch_object($result)) {
        $block['category-'. $category->cid]['info'] = t('!title category latest items', array('!title' => $category->title));
      }
      $result = db_query('SELECT fid, title FROM {aggregator_feed} ORDER BY fid');
      while ($feed = db_fetch_object($result)) {
        $block['feed-'. $feed->fid]['info'] = t('!title feed latest items', array('!title' => $feed->title));
      }
    }
    else if ($op == 'configure') {
      list($type, $id) = explode('-', $delta);
      if ($type == 'category') {
        $value = db_result(db_query('SELECT block FROM {aggregator_category} WHERE cid = %d', $id));
      }
      else {
        $value = db_result(db_query('SELECT block FROM {aggregator_feed} WHERE fid = %d', $id));
      }
      $form['block'] = array('#type' => 'select', '#title' => t('Number of news items in block'), '#default_value' => $value, '#options' => drupal_map_assoc(array(2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)));
      return $form;
    }
    else if ($op == 'save') {
      list($type, $id) = explode('-', $delta);
      if ($type == 'category') {
        $value = db_query('UPDATE {aggregator_category} SET block = %d WHERE cid = %d', $edit['block'], $id);
      }
      else {
        $value = db_query('UPDATE {aggregator_feed} SET block = %d WHERE fid = %d', $edit['block'], $id);
      }
    }
    else if ($op == 'view') {
      list($type, $id) = explode('-', $delta);
      switch ($type) {
        case 'feed':
          if ($feed = db_fetch_object(db_query('SELECT fid, title, block FROM {aggregator_feed} WHERE fid = %d', $id))) {
            $block['subject'] = check_plain($feed->title);
            $result = db_query_range('SELECT * FROM {aggregator_item} WHERE fid = %d ORDER BY timestamp DESC, iid DESC', $feed->fid, 0, $feed->block);
            $read_more = theme('more_link', url('aggregator/sources/'. $feed->fid), t("View this feed's recent news."));
          }
          break;

        case 'category':
          if ($category = db_fetch_object(db_query('SELECT cid, title, block FROM {aggregator_category} WHERE cid = %d', $id))) {
            $block['subject'] = check_plain($category->title);
            $result = db_query_range('SELECT i.* FROM {aggregator_category_item} ci LEFT JOIN {aggregator_item} i ON ci.iid = i.iid WHERE ci.cid = %d ORDER BY i.timestamp DESC, i.iid DESC', $category->cid, 0, $category->block);
            $read_more = theme('more_link', url('aggregator/categories/'. $category->cid), t("View this category's recent news."));
          }
          break;
      }
      $items = array();
      while ($item = db_fetch_object($result)) {
        $items[] = theme('aggregator_block_item', $item);
      }

      // Only display the block if there are items to show.
      if (count($items) > 0) {
        $block['content'] = theme('item_list', $items) . $read_more;
      }
    }
    if (isset($block)) {
      return $block;
    }
  }
}

/**
 * Add/edit/delete aggregator categories.
 */
function aggregator_save_category($edit) {
  $link_path = 'aggregator/categories/';
  if (!empty($edit['cid'])) {
    $link_path .= $edit['cid'];
    if (!empty($edit['title'])) {
      db_query("UPDATE {aggregator_category} SET title = '%s', description = '%s' WHERE cid = %d", $edit['title'], $edit['description'], $edit['cid']);
      $op = 'update';
    }
    else {
      db_query('DELETE FROM {aggregator_category} WHERE cid = %d', $edit['cid']);
      $edit['title'] = '';
      $op = 'delete';
    }
  }
  else if (!empty($edit['title'])) {
    // A single unique id for bundles and feeds, to use in blocks
    db_query("INSERT INTO {aggregator_category} (title, description, block) VALUES ('%s', '%s', 5)", $edit['title'], $edit['description']);
    $link_path .= db_last_insert_id('aggregator', 'cid');
    $op = 'insert';
  }
  if (isset($op)) {
    menu_link_maintain('aggregator', $op, $link_path, $edit['title']);
  }
}

/**
 * Add/edit/delete an aggregator feed.
 */
function aggregator_save_feed($edit) {
  if (!empty($edit['fid'])) {
    // An existing feed is being modified, delete the category listings.
    db_query('DELETE FROM {aggregator_category_feed} WHERE fid = %d', $edit['fid']);
  }
  if (!empty($edit['fid']) && !empty($edit['title'])) {
    db_query("UPDATE {aggregator_feed} SET title = '%s', url = '%s', refresh = %d WHERE fid = %d", $edit['title'], $edit['url'], $edit['refresh'], $edit['fid']);
  }
  else if (!empty($edit['fid'])) {
    $items = array();
    $result = db_query('SELECT iid FROM {aggregator_item} WHERE fid = %d', $edit['fid']);
    while ($item = db_fetch_object($result)) {
      $items[] = "iid = $item->iid";
    }
    if (!empty($items)) {
      db_query('DELETE FROM {aggregator_category_item} WHERE '. implode(' OR ', $items));
    }
    db_query('DELETE FROM {aggregator_feed} WHERE fid = %d', $edit['fid']);
    db_query('DELETE FROM {aggregator_item} WHERE fid = %d', $edit['fid']);
  }
  else if (!empty($edit['title'])) {
    db_query("INSERT INTO {aggregator_feed} (title, url, refresh, block, description, image) VALUES ('%s', '%s', %d, 5, '', '')", $edit['title'], $edit['url'], $edit['refresh']);
    // A single unique id for bundles and feeds, to use in blocks.
    $edit['fid'] = db_last_insert_id('aggregator_feed', 'fid');
  }
  if (!empty($edit['title'])) {
    // The feed is being saved, save the categories as well.
    if (!empty($edit['category'])) {
      foreach ($edit['category'] as $cid => $value) {
        if ($value) {
          db_query('INSERT INTO {aggregator_category_feed} (fid, cid) VALUES (%d, %d)', $edit['fid'], $cid);
        }
      }
    }
  }
}

function aggregator_remove($feed) {
  $result = db_query('SELECT iid FROM {aggregator_item} WHERE fid = %d', $feed['fid']);
  while ($item = db_fetch_object($result)) {
    $items[] = "iid = $item->iid";
  }
  if (!empty($items)) {
    db_query('DELETE FROM {aggregator_category_item} WHERE '. implode(' OR ', $items));
  }
  db_query('DELETE FROM {aggregator_item} WHERE fid = %d', $feed['fid']);
  db_query("UPDATE {aggregator_feed} SET checked = 0, etag = '', modified = 0 WHERE fid = %d", $feed['fid']);
  drupal_set_message(t('The news items from %site have been removed.', array('%site' => $feed['title'])));
}

/**
 * Call-back function used by the XML parser.
 */
function aggregator_element_start($parser, $name, $attributes) {
  global $item, $element, $tag, $items, $channel;

  switch ($name) {
    case 'IMAGE':
    case 'TEXTINPUT':
    case 'CONTENT':
    case 'SUMMARY':
    case 'TAGLINE':
    case 'SUBTITLE':
    case 'LOGO':
    case 'INFO':
      $element = $name;
      break;
    case 'ID':
      if ($element != 'ITEM') {
        $element = $name;
      }
    case 'LINK':
      if (!empty($attributes['REL']) && $attributes['REL'] == 'alternate') {
        if ($element == 'ITEM') {
          $items[$item]['LINK'] = $attributes['HREF'];
        }
        else {
          $channel['LINK'] = $attributes['HREF'];
        }
      }
      break;
    case 'ITEM':
      $element = $name;
      $item += 1;
      break;
    case 'ENTRY':
      $element = 'ITEM';
      $item += 1;
      break;
  }

  $tag = $name;
}

/**
 * Call-back function used by the XML parser.
 */
function aggregator_element_end($parser, $name) {
  global $element;

  switch ($name) {
    case 'IMAGE':
    case 'TEXTINPUT':
    case 'ITEM':
    case 'ENTRY':
    case 'CONTENT':
    case 'INFO':
      $element = '';
      break;
    case 'ID':
      if ($element == 'ID') {
        $element = '';
      }
  }
}

/**
 * Call-back function used by the XML parser.
 */
function aggregator_element_data($parser, $data) {
  global $channel, $element, $items, $item, $image, $tag;
  $items += array($item => array());
  switch ($element) {
    case 'ITEM':
      $items[$item] += array($tag => '');
      $items[$item][$tag] .= $data;
      break;
    case 'IMAGE':
    case 'LOGO':
      $image += array($tag => '');
      $image[$tag] .= $data;
      break;
    case 'LINK':
      if ($data) {
        $items[$item] += array($tag => '');
        $items[$item][$tag] .= $data;
      }
      break;
    case 'CONTENT':
      $items[$item] += array('CONTENT' => '');
      $items[$item]['CONTENT'] .= $data;
      break;
    case 'SUMMARY':
      $items[$item] += array('SUMMARY' => '');
      $items[$item]['SUMMARY'] .= $data;
      break;
    case 'TAGLINE':
    case 'SUBTITLE':
      $channel += array('DESCRIPTION' => '');
      $channel['DESCRIPTION'] .= $data;
      break;
    case 'INFO':
    case 'ID':
    case 'TEXTINPUT':
      // The sub-element is not supported. However, we must recognize
      // it or its contents will end up in the item array.
      break;
    default:
      $channel += array($tag => '');
      $channel[$tag] .= $data;
  }
}

/**
 * Checks a news feed for new items.
 */
function aggregator_refresh($feed) {
  global $channel, $image;

  // Generate conditional GET headers.
  $headers = array();
  if ($feed['etag']) {
    $headers['If-None-Match'] = $feed['etag'];
  }
  if ($feed['modified']) {
    $headers['If-Modified-Since'] = gmdate('D, d M Y H:i:s', $feed['modified']) .' GMT';
  }

  // Request feed.
  $result = drupal_http_request($feed['url'], $headers);

  // Process HTTP response code.
  switch ($result->code) {
    case 304:
      db_query('UPDATE {aggregator_feed} SET checked = %d WHERE fid = %d', time(), $feed['fid']);
      drupal_set_message(t('There is no new syndicated content from %site.', array('%site' => $feed['title'])));
      break;
    case 301:
      $feed['url'] = $result->redirect_url;
      watchdog('aggregator', 'Updated URL for feed %title to %url.', array('%title' => $feed['title'], '%url' => $feed['url']));

    case 200:
    case 302:
    case 307:
      // Filter the input data:
     if (aggregator_parse_feed($result->data, $feed)) {

        $modified = empty($result->headers['Last-Modified']) ? 0 : strtotime($result->headers['Last-Modified']);

        /*
        ** Prepare the channel data:
        */

        foreach ($channel as $key => $value) {
          $channel[$key] = trim($value);
        }

        /*
        ** Prepare the image data (if any):
        */

        foreach ($image as $key => $value) {
          $image[$key] = trim($value);
        }

        if (!empty($image['LINK']) && !empty($image['URL']) && !empty($image['TITLE'])) {
          // Note, we should really use theme_image() here but that only works with local images it won't work with images fetched with a URL unless PHP version > 5
          $image = '<a href="'. check_url($image['LINK']) .'" class="feed-image"><img src="'. check_url($image['URL']) .'" alt="'. check_plain($image['TITLE']) .'" /></a>';
        }
        else {
          $image = NULL;
        }

        $etag = empty($result->headers['ETag']) ? '' : $result->headers['ETag'];
        /*
        ** Update the feed data:
        */

        db_query("UPDATE {aggregator_feed} SET url = '%s', checked = %d, link = '%s', description = '%s', image = '%s', etag = '%s', modified = %d WHERE fid = %d", $feed['url'], time(), $channel['LINK'], $channel['DESCRIPTION'], $image, $etag, $modified, $feed['fid']);

        /*
        ** Clear the cache:
        */

        cache_clear_all();

        watchdog('aggregator', 'There is new syndicated content from %site.', array('%site' => $feed['title']));
        drupal_set_message(t('There is new syndicated content from %site.', array('%site' => $feed['title'])));
      }
      break;
    default:
      watchdog('aggregator', 'The feed from %site seems to be broken, due to "%error".', array('%site' => $feed['title'], '%error' => $result->code .' '. $result->error), WATCHDOG_WARNING);
      drupal_set_message(t('The feed from %site seems to be broken, because of error "%error".', array('%site' => $feed['title'], '%error' => $result->code .' '. $result->error)));
  }
}

/**
 * Parse the W3C date/time format, a subset of ISO 8601. PHP date parsing
 * functions do not handle this format.
 * See http://www.w3.org/TR/NOTE-datetime for more information.
 * Originally from MagpieRSS (http://magpierss.sourceforge.net/).
 *
 * @param $date_str A string with a potentially W3C DTF date.
 * @return A timestamp if parsed successfully or -1 if not.
 */
function aggregator_parse_w3cdtf($date_str) {
  if (preg_match('/(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2})(:(\d{2}))?(?:([-+])(\d{2}):?(\d{2})|(Z))?/', $date_str, $match)) {
    list($year, $month, $day, $hours, $minutes, $seconds) = array($match[1], $match[2], $match[3], $match[4], $match[5], $match[6]);
    // calc epoch for current date assuming GMT
    $epoch = gmmktime($hours, $minutes, $seconds, $month, $day, $year);
    if ($match[10] != 'Z') { // Z is zulu time, aka GMT
      list($tz_mod, $tz_hour, $tz_min) = array($match[8], $match[9], $match[10]);
      // zero out the variables
      if (!$tz_hour) {
        $tz_hour = 0;
      }
      if (!$tz_min) {
        $tz_min = 0;
      }
      $offset_secs = (($tz_hour * 60) + $tz_min) * 60;
      // is timezone ahead of GMT?  then subtract offset
      if ($tz_mod == '+') {
        $offset_secs *= -1;
      }
      $epoch += $offset_secs;
    }
    return $epoch;
  }
  else {
    return FALSE;
  }
}

function aggregator_parse_feed(&$data, $feed) {
  global $items, $image, $channel;

  // Unset the global variables before we use them:
  unset($GLOBALS['element'], $GLOBALS['item'], $GLOBALS['tag']);
  $items = array();
  $image = array();
  $channel = array();

  // parse the data:
  $xml_parser = drupal_xml_parser_create($data);
  xml_set_element_handler($xml_parser, 'aggregator_element_start', 'aggregator_element_end');
  xml_set_character_data_handler($xml_parser, 'aggregator_element_data');

  if (!xml_parse($xml_parser, $data, 1)) {
    watchdog('aggregator', 'The feed from %site seems to be broken, due to an error "%error" on line %line.', array('%site' => $feed['title'], '%error' => xml_error_string(xml_get_error_code($xml_parser)), '%line' => xml_get_current_line_number($xml_parser)), WATCHDOG_WARNING);
    drupal_set_message(t('The feed from %site seems to be broken, because of error "%error" on line %line.', array('%site' => $feed['title'], '%error' => xml_error_string(xml_get_error_code($xml_parser)), '%line' => xml_get_current_line_number($xml_parser))), 'error');
    return 0;
  }
  xml_parser_free($xml_parser);

  /*
  ** We reverse the array such that we store the first item last,
  ** and the last item first. In the database, the newest item
  ** should be at the top.
  */

  $items = array_reverse($items);

  // Initialize variables
  $title = $link = $author = $description = $guid = NULL;
  foreach ($items as $item) {
    unset($title, $link, $author, $description, $guid);

    // Prepare the item:
    foreach ($item as $key => $value) {
      $item[$key] = trim($value);
    }

    /*
    ** Resolve the item's title. If no title is found, we use
    ** up to 40 characters of the description ending at a word
    ** boundary but not splitting potential entities.
    */

    if (!empty($item['TITLE'])) {
      $title = $item['TITLE'];
    }
    elseif (!empty($item['DESCRIPTION'])) {
      $title = preg_replace('/^(.*)[^\w;&].*?$/', "\\1", truncate_utf8($item['DESCRIPTION'], 40));
    }
    else {
      $title = '';
    }

    /*
    ** Resolve the items link.
    */

    if (!empty($item['LINK'])) {
      $link = $item['LINK'];
    }
    else {
      $link = $feed['link'];
    }
    $guid = isset($item['GUID']) ? $item['GUID'] : '';

    /**
     * Atom feeds have a CONTENT and/or SUMMARY tag instead of a DESCRIPTION tag
     */
    if (!empty($item['CONTENT:ENCODED'])) {
      $item['DESCRIPTION'] = $item['CONTENT:ENCODED'];
    }
    else if (!empty($item['SUMMARY'])) {
      $item['DESCRIPTION'] = $item['SUMMARY'];
    }
    else if (!empty($item['CONTENT'])) {
      $item['DESCRIPTION'] = $item['CONTENT'];
    }

    /*
    ** Try to resolve and parse the item's publication date. If no
    ** date is found, we use the current date instead.
    */

    $date = 'now';
    foreach (array('PUBDATE', 'DC:DATE', 'DCTERMS:ISSUED', 'DCTERMS:CREATED', 'DCTERMS:MODIFIED', 'ISSUED', 'CREATED', 'MODIFIED', 'PUBLISHED', 'UPDATED') as $key) {
      if (!empty($item[$key])) {
        $date = $item[$key];
        break;
      }
    }

    $timestamp = strtotime($date); // As of PHP 5.1.0, strtotime returns FALSE on failure instead of -1.
    if ($timestamp <= 0) {
      $timestamp = aggregator_parse_w3cdtf($date); // Returns FALSE on failure
      if (!$timestamp) {
        $timestamp = time(); // better than nothing
      }
    }

    /*
    ** Save this item. Try to avoid duplicate entries as much as
    ** possible. If we find a duplicate entry, we resolve it and
    ** pass along its ID is such that we can update it if needed.
    */

    if (!empty($guid)) {
      $entry = db_fetch_object(db_query("SELECT iid FROM {aggregator_item} WHERE fid = %d AND guid = '%s'", $feed['fid'], $guid));
    }
    else if ($link && $link != $feed['link'] && $link != $feed['url']) {
      $entry = db_fetch_object(db_query("SELECT iid FROM {aggregator_item} WHERE fid = %d AND link = '%s'", $feed['fid'], $link));
    }
    else {
      $entry = db_fetch_object(db_query("SELECT iid FROM {aggregator_item} WHERE fid = %d AND title = '%s'", $feed['fid'], $title));
    }
    $item += array('AUTHOR' => '', 'DESCRIPTION' => '');
    aggregator_save_item(array('iid' => (isset($entry->iid) ? $entry->iid:  ''), 'fid' => $feed['fid'], 'timestamp' => $timestamp, 'title' => $title, 'link' => $link, 'author' => $item['AUTHOR'], 'description' => $item['DESCRIPTION'], 'guid' => $guid));
  }

  /*
  ** Remove all items that are older than flush item timer:
  */

  $age = time() - variable_get('aggregator_clear', 9676800);
  $result = db_query('SELECT iid FROM {aggregator_item} WHERE fid = %d AND timestamp < %d', $feed['fid'], $age);