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root / drupal7 / modules / aggregator / aggregator.parser.inc @ b0dc3a2e

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<?php
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/**
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 * @file
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 * Parser functions for the aggregator module.
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 */
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/**
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 * Implements hook_aggregator_parse_info().
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 */
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function aggregator_aggregator_parse_info() {
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  return array(
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    'title' => t('Default parser'),
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    'description' => t('Parses RSS, Atom and RDF feeds.'),
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  );
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}
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/**
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 * Implements hook_aggregator_parse().
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 */
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function aggregator_aggregator_parse($feed) {
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  global $channel, $image;
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  // Filter the input data.
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  if (aggregator_parse_feed($feed->source_string, $feed)) {
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    $modified = empty($feed->http_headers['last-modified']) ? 0 : strtotime($feed->http_headers['last-modified']);
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    // Prepare the channel data.
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    foreach ($channel as $key => $value) {
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      $channel[$key] = trim($value);
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    }
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    // Prepare the image data (if any).
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    foreach ($image as $key => $value) {
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      $image[$key] = trim($value);
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    }
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    $etag = empty($feed->http_headers['etag']) ? '' : $feed->http_headers['etag'];
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    // Add parsed data to the feed object.
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    $feed->link = !empty($channel['link']) ? $channel['link'] : '';
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    $feed->description = !empty($channel['description']) ? $channel['description'] : '';
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    $feed->image = !empty($image['url']) ? $image['url'] : '';
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    $feed->etag = $etag;
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    $feed->modified = $modified;
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    // Clear the cache.
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    cache_clear_all();
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    return TRUE;
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  }
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  return FALSE;
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}
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/**
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 * Parses a feed and stores its items.
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 *
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 * @param $data
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 *   The feed data.
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 * @param $feed
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 *   An object describing the feed to be parsed.
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 *
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 * @return
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 *   FALSE on error, TRUE otherwise.
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 */
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function aggregator_parse_feed(&$data, $feed) {
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  global $items, $image, $channel;
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  // Unset the global variables before we use them.
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  unset($GLOBALS['element'], $GLOBALS['item'], $GLOBALS['tag']);
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  $items = array();
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  $image = array();
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  $channel = array();
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  // Parse the data.
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  $xml_parser = drupal_xml_parser_create($data);
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  xml_set_element_handler($xml_parser, 'aggregator_element_start', 'aggregator_element_end');
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  xml_set_character_data_handler($xml_parser, 'aggregator_element_data');
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  if (!xml_parse($xml_parser, $data, 1)) {
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    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);
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    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($xml_parser))), 'error');
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    return FALSE;
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  }
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  xml_parser_free($xml_parser);
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  // We reverse the array such that we store the first item last, and the last
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  // item first. In the database, the newest item should be at the top.
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  $items = array_reverse($items);
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  // Initialize items array.
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  $feed->items = array();
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  foreach ($items as $item) {
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    // Prepare the item:
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    foreach ($item as $key => $value) {
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      $item[$key] = trim($value);
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    }
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    // Resolve the item's title. If no title is found, we use up to 40
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    // characters of the description ending at a word boundary, but not
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    // splitting potential entities.
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    if (!empty($item['title'])) {
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      $item['title'] = $item['title'];
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    }
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    elseif (!empty($item['description'])) {
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      $item['title'] = preg_replace('/^(.*)[^\w;&].*?$/', "\\1", truncate_utf8($item['description'], 40));
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    }
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    else {
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      $item['title'] = '';
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    }
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    // Resolve the items link.
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    if (!empty($item['link'])) {
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      $item['link'] = $item['link'];
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    }
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    else {
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      $item['link'] = $feed->link;
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    }
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    // Atom feeds have an ID tag instead of a GUID tag.
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    if (!isset($item['guid'])) {
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      $item['guid'] = isset($item['id']) ? $item['id'] : '';
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    }
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    // Atom feeds have a content and/or summary tag instead of a description tag.
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    if (!empty($item['content:encoded'])) {
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      $item['description'] = $item['content:encoded'];
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    }
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    elseif (!empty($item['summary'])) {
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      $item['description'] = $item['summary'];
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    }
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    elseif (!empty($item['content'])) {
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      $item['description'] = $item['content'];
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    }
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    // Try to resolve and parse the item's publication date.
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    $date = '';
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    foreach (array('pubdate', 'dc:date', 'dcterms:issued', 'dcterms:created', 'dcterms:modified', 'issued', 'created', 'modified', 'published', 'updated') as $key) {
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      if (!empty($item[$key])) {
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        $date = $item[$key];
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        break;
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      }
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    }
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    $item['timestamp'] = strtotime($date);
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    if ($item['timestamp'] === FALSE) {
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      $item['timestamp'] = aggregator_parse_w3cdtf($date); // Aggregator_parse_w3cdtf() returns FALSE on failure.
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    }
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    // Resolve dc:creator tag as the item author if author tag is not set.
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    if (empty($item['author']) && !empty($item['dc:creator'])) {
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      $item['author'] = $item['dc:creator'];
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    }
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    $item += array('author' => '', 'description' => '');
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    // Store on $feed object. This is where processors will look for parsed items.
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    $feed->items[] = $item;
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  }
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  return TRUE;
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}
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/**
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 * Performs an action when an opening tag is encountered.
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 *
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 * Callback function used by xml_parse() within aggregator_parse_feed().
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 */
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function aggregator_element_start($parser, $name, $attributes) {
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  global $item, $element, $tag, $items, $channel;
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  $name = strtolower($name);
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  switch ($name) {
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    case 'image':
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    case 'textinput':
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    case 'summary':
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    case 'tagline':
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    case 'subtitle':
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    case 'logo':
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    case 'info':
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      $element = $name;
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      break;
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    case 'id':
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    case 'content':
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      if ($element != 'item') {
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        $element = $name;
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      }
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    case 'link':
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      // According to RFC 4287, link elements in Atom feeds without a 'rel'
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      // attribute should be interpreted as though the relation type is
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      // "alternate".
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      if (!empty($attributes['HREF']) && (empty($attributes['REL']) || $attributes['REL'] == 'alternate')) {
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        if ($element == 'item') {
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          $items[$item]['link'] = $attributes['HREF'];
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        }
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        else {
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          $channel['link'] = $attributes['HREF'];
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        }
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      }
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      break;
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    case 'item':
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      $element = $name;
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      $item += 1;
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      break;
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    case 'entry':
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      $element = 'item';
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      $item += 1;
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      break;
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  }
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  $tag = $name;
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}
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/**
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 * Performs an action when a closing tag is encountered.
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 *
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 * Callback function used by xml_parse() within aggregator_parse_feed().
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 */
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function aggregator_element_end($parser, $name) {
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  global $element;
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  switch ($name) {
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    case 'image':
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    case 'textinput':
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    case 'item':
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    case 'entry':
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    case 'info':
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      $element = '';
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      break;
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    case 'id':
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    case 'content':
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      if ($element == $name) {
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        $element = '';
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      }
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  }
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}
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/**
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 * Performs an action when data is encountered.
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 *
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 * Callback function used by xml_parse() within aggregator_parse_feed().
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 */
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function aggregator_element_data($parser, $data) {
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  global $channel, $element, $items, $item, $image, $tag;
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  $items += array($item => array());
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  switch ($element) {
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    case 'item':
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      $items[$item] += array($tag => '');
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      $items[$item][$tag] .= $data;
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      break;
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    case 'image':
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    case 'logo':
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      $image += array($tag => '');
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      $image[$tag] .= $data;
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      break;
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    case 'link':
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      if ($data) {
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        $items[$item] += array($tag => '');
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        $items[$item][$tag] .= $data;
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      }
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      break;
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    case 'content':
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      $items[$item] += array('content' => '');
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      $items[$item]['content'] .= $data;
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      break;
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    case 'summary':
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      $items[$item] += array('summary' => '');
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      $items[$item]['summary'] .= $data;
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      break;
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    case 'tagline':
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    case 'subtitle':
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      $channel += array('description' => '');
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      $channel['description'] .= $data;
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      break;
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    case 'info':
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    case 'id':
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    case 'textinput':
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      // The sub-element is not supported. However, we must recognize
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      // it or its contents will end up in the item array.
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      break;
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    default:
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      $channel += array($tag => '');
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      $channel[$tag] .= $data;
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  }
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}
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/**
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 * Parses the W3C date/time format, a subset of ISO 8601.
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 *
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 * PHP date parsing functions do not handle this format. See
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 * http://www.w3.org/TR/NOTE-datetime for more information. Originally from
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 * MagpieRSS (http://magpierss.sourceforge.net/).
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 *
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 * @param $date_str
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 *   A string with a potentially W3C DTF date.
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 *
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 * @return
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 *   A timestamp if parsed successfully or FALSE if not.
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 */
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function aggregator_parse_w3cdtf($date_str) {
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  if (preg_match('/(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2})(:(\d{2}))?(?:([-+])(\d{2}):?(\d{2})|(Z))?/', $date_str, $match)) {
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    list($year, $month, $day, $hours, $minutes, $seconds) = array($match[1], $match[2], $match[3], $match[4], $match[5], $match[6]);
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    // Calculate the epoch for current date assuming GMT.
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    $epoch = gmmktime($hours, $minutes, $seconds, $month, $day, $year);
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    if ($match[10] != 'Z') { // Z is zulu time, aka GMT
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      list($tz_mod, $tz_hour, $tz_min) = array($match[8], $match[9], $match[10]);
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      // Zero out the variables.
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      if (!$tz_hour) {
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        $tz_hour = 0;
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      }
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      if (!$tz_min) {
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        $tz_min = 0;
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      }
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      $offset_secs = (($tz_hour * 60) + $tz_min) * 60;
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      // Is timezone ahead of GMT?  If yes, subtract offset.
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      if ($tz_mod == '+') {
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        $offset_secs *= -1;
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      }
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      $epoch += $offset_secs;
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    }
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    return $epoch;
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  }
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  else {
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    return FALSE;
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  }
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}