aggregator.module

<?php
// $Id$

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

/**
 * Implementation of hook_help().
 */
function aggregator_help($section) {
  switch ($section) {
    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_menu().
 */
function aggregator_menu($may_cache) {
  $items = array();
  $edit = user_access('administer news feeds');
  $view = user_access('access news feeds');

  if ($may_cache) {
    $items[] = array('path' => 'admin/content/aggregator',
      'title' => t('RSS aggregator'),
      'description' => t("Configure which content your site aggregates from other sites, how often it polls them, and how they're categorized."),
      'callback' => 'aggregator_admin_overview',
      'access' => $edit);
    $items[] = array('path' => 'admin/content/aggregator/add/feed',
      'title' => t('Add feed'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('aggregator_form_feed'),
      'access' => $edit,
      'type' => MENU_LOCAL_TASK);
    $items[] = array('path' => 'admin/content/aggregator/add/category',
      'title' => t('Add category'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('aggregator_form_category'),
      'access' => $edit,
      'type' => MENU_LOCAL_TASK);
    $items[] = array('path' => 'admin/content/aggregator/remove',
      'title' => t('Remove items'),
      'callback' => 'aggregator_admin_remove_feed',
      'access' => $edit,
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/content/aggregator/update',
      'title' => t('Update items'),
      'callback' => 'aggregator_admin_refresh_feed',
      'access' => $edit,
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/content/aggregator/list',
      'title' => t('List'),
      'type' => MENU_DEFAULT_LOCAL_TASK,
      'weight' => -10);
    $items[] = array('path' => 'admin/content/aggregator/settings',
      'title' => t('Settings'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('aggregator_admin_settings'),
      'type' => MENU_LOCAL_TASK,
      'weight' => 10,
      'access' => $edit);

    $items[] = array('path' => 'aggregator',
      'title' => t('News aggregator'),
      'callback' => 'aggregator_page_last',
      'access' => $view,
      'weight' => 5);
    $items[] = array('path' => 'aggregator/sources',
      'title' => t('Sources'),
      'callback' => 'aggregator_page_sources',
      'access' => $view);
    $items[] = array('path' => 'aggregator/categories',
      'title' => t('Categories'),
      'callback' => 'aggregator_page_categories',
      'access' => $view,
      'type' => MENU_ITEM_GROUPING);
    $items[] = array('path' => 'aggregator/rss',
      'title' => t('RSS feed'),
      'callback' => 'aggregator_page_rss',
      'access' => $view,
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'aggregator/opml',
      'title' => t('OPML feed'),
      'callback' => 'aggregator_page_opml',
      'access' => $view,
      'type' => MENU_CALLBACK);

    $result = db_query('SELECT title, cid FROM {aggregator_category} ORDER BY title');
    while ($category = db_fetch_array($result)) {
      $items[] = array('path' => 'aggregator/categories/'. $category['cid'],
        'title' => $category['title'],
        'callback' => 'aggregator_page_category',
        'access' => $view);
    }
  }
  else {
    // Add the CSS for this module
    // We put this in !$may_cache so it's only added once per request
    drupal_add_css(drupal_get_path('module', 'aggregator') .'/aggregator.css');

    if (arg(0) == 'aggregator' && is_numeric(arg(2))) {
      if (arg(1) == 'sources') {
        $feed = aggregator_get_feed(arg(2));
        if ($feed) {
          $items[] = array('path' => 'aggregator/sources/'. $feed['fid'],
            'title' => $feed['title'],
            'callback' => 'aggregator_page_source',
            'access' => $view,
            'type' => MENU_CALLBACK);
          $items[] = array('path' => 'aggregator/sources/'. $feed['fid'] .'/view',
            'title' => t('View'),
            'type' => MENU_DEFAULT_LOCAL_TASK,
            'weight' => -10);
          $items[] = array('path' => 'aggregator/sources/'. $feed['fid'] .'/categorize',
            'title' => t('Categorize'),
            'callback' => 'drupal_get_form',
            'callback arguments' => array('aggregator_page_source'),
            'access' => $edit,
            'type' => MENU_LOCAL_TASK);
          $items[] = array('path' => 'aggregator/sources/'. $feed['fid'] .'/configure',
            'title' => t('Configure'),
            'callback' => 'drupal_get_form',
            'callback arguments' => array('aggregator_form_feed', $feed),
            'access' => $edit,
            'type' => MENU_LOCAL_TASK,
            'weight' => 1);
        }
      }
      else if (arg(1) == 'categories') {
        $category = aggregator_get_category(arg(2));
        if ($category) {
          $items[] = array('path' => 'aggregator/categories/'. $category['cid'] .'/view',
            'title' => t('View'),
            'type' => MENU_DEFAULT_LOCAL_TASK,
            'weight' => -10);
          $items[] = array('path' => 'aggregator/categories/'. $category['cid'] .'/categorize',
            'title' => t('Categorize'),
            'callback' => 'drupal_get_form',
            'callback arguments' => array('aggregator_page_category'),
            'access' => $edit,
            'type' => MENU_LOCAL_TASK);
          $items[] = array('path' => 'aggregator/categories/'. $category['cid'] .'/configure',
            'title' => t('Configure'),
            'callback' => 'drupal_get_form',
            'callback arguments' => array('aggregator_form_category', $category),
            'access' => $edit,
            'type' => MENU_LOCAL_TASK,
            'weight' => 1);
        }
      }
    }
    else if (arg(2) == 'aggregator' && is_numeric(arg(5))) {
      if (arg(4) == 'feed') {
        $feed = aggregator_get_feed(arg(5));
        if ($feed) {
          $items[] = array('path' => 'admin/content/aggregator/edit/feed/'. $feed['fid'],
            'title' => t('Edit feed'),
            'callback' => 'drupal_get_form',
            'callback arguments' => array('aggregator_form_feed', $feed),
            'access' => $edit,
            'type' => MENU_CALLBACK);
        }
      }
      else {
        $category = aggregator_get_category(arg(5));
        if ($category) {
          $items[] = array('path' => 'admin/content/aggregator/edit/category/'. $category['cid'],
            'title' => t('Edit category'),
            'callback' => 'drupal_get_form',
            'callback arguments' => array('aggregator_form_category', $category),
            'access' => $edit,
            'type' => MENU_CALLBACK);
        }
      }
    }
  }

  return $items;
}

function aggregator_admin_settings() {
  $items = array(0 => t('none')) + drupal_map_assoc(array(3, 5, 10, 15, 20, 25), '_aggregator_items');
  $period = drupal_map_assoc(array(3600, 10800, 21600, 32400, 43200, 86400, 172800, 259200, 604800, 1209600, 2419200, 4838400, 9676800), 'format_interval');

  $form['aggregator_allowed_html_tags'] = array(
    '#type' => 'textfield', '#title' => t('Allowed HTML tags'), '#size' => 80, '#maxlength' => 255,
    '#default_value' => variable_get('aggregator_allowed_html_tags', '<a> <b> <br> <dd> <dl> <dt> <em> <i> <li> <ol> <p> <strong> <u> <ul>'),
    '#description' => t('The list of tags which are allowed in feeds, i.e., which will not be removed by Drupal.')
  );

  $form['aggregator_summary_items'] = array(
    '#type' => 'select', '#title' => t('Items shown in sources and categories pages') ,
    '#default_value' => variable_get('aggregator_summary_items', 3), '#options' => $items,
    '#description' =>  t('The number of items which will be shown with each feed or category in the feed and category summary pages.')
  );

  $form['aggregator_clear'] = array(
    '#type' => 'select', '#title' => t('Discard news items older than'),
    '#default_value' => variable_get('aggregator_clear', 9676800), '#options' => $period,
    '#description' => t('Older news items will be automatically discarded. Requires crontab.')
  );

  $form['aggregator_category_selector'] = array(
    '#type' => 'radios', '#title' => t('Category selection type'), '#default_value' => variable_get('aggregator_category_selector', 'checkboxes'),
    '#options' => array('checkboxes' => t('checkboxes'), 'select' => t('multiple selector')),
    '#description' => t('The type of category selection widget which is shown on categorization pages. Checkboxes are easier to use; a multiple selector is good for working with large numbers of categories.')
  );

  return system_settings_form($form);
}

/**
 * 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);
            $block['content'] = '<div class="more-link">'. l(t('more'), 'aggregator/sources/'. $feed->fid, array('title' => t("View this feed's recent news."))) .'</div>';
          }
          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);
            $block['content'] = '<div class="more-link">'. l(t('more'), 'aggregator/categories/'. $category->cid, array('title' => t("View this category's recent news."))) .'</div>';
          }
          break;
      }
      $items = array();
      while ($item = db_fetch_object($result)) {
        $items[] = theme('aggregator_block_item', $item);
      }
      $block['content'] = theme('item_list', $items) . $block['content'];
    }
    return $block;
  }
}

/**
 * Generate a form to add/edit/delete aggregator categories.
 */
 function aggregator_form_category($edit = array()) {
  $form['title'] = array('#type' => 'textfield',
    '#title' => t('Title'),
    '#default_value' => $edit['title'],
    '#maxlength' => 64,
    '#required' => TRUE,
  );
  $form['description'] = array('#type' => 'textarea',
    '#title' => t('Description'),
    '#default_value' => $edit['description'],
  );
  $form['submit'] = array('#type' => 'submit', '#value' => t('Submit'));

  if ($edit['cid']) {
    $form['delete'] = array('#type' => 'submit', '#value' => t('Delete'));
    $form['cid'] = array('#type' => 'hidden', '#value' => $edit['cid']);
  }

  return $form;
}

/**
 * Validate aggregator_form_feed form submissions.
 */
function aggregator_form_category_validate($form_id, $form_values) {
  if ($form_values['op'] == t('Submit')) {
    // Check for duplicate titles
    if (isset($form_values['cid'])) {
      $category = db_fetch_object(db_query("SELECT cid FROM {aggregator_category} WHERE title = '%s' AND cid != %d", $form_values['title'], $form_values['cid']));
    }
    else {
      $category = db_fetch_object(db_query("SELECT cid FROM {aggregator_category} WHERE title = '%s'", $form_values['title']));
    }
    if ($category) {
      form_set_error('title', t('A category named %category already exists. Please enter a unique title.', array('%category' => $form_values['title'])));
    }
  }
}

/**
 * Process aggregator_form_category form submissions.
 * @todo Add delete confirmation dialog.
 */
function aggregator_form_category_submit($form_id, $form_values) {
  if ($form_values['op'] == t('Delete')) {
    $title = $form_values['title'];
    // Unset the title:
    unset($form_values['title']);
  }
  aggregator_save_category($form_values);
  menu_rebuild();
  if (isset($form_values['cid'])) {
    if (isset($form_values['title'])) {
      drupal_set_message(t('The category %category has been updated.', array('%category' => $form_values['title'])));
      if (arg(0) == 'admin') {
        return 'admin/content/aggregator/';
      }
      else {
        return 'aggregator/categories/'. $form_values['cid'];
      }
    }
    else {
      watchdog('aggregator', t('Category %category deleted.', array('%category' => $title)));
      drupal_set_message(t('The category %category has been deleted.', array('%category' => $title)));
      if (arg(0) == 'admin') {
        return 'admin/content/aggregator/';
      }
      else {
        return 'aggregator/categories/';
      }
    }
  }
  else {
    watchdog('aggregator', t('Category %category added.', array('%category' => $form_values['title'])), WATCHDOG_NOTICE, l(t('view'), 'admin/content/aggregator'));
    drupal_set_message(t('The category %category has been added.', array('%category' => $form_values['title'])));
  }
}

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

/**
 * Generate a form to add/edit feed sources.
 */
function aggregator_form_feed($edit = array()) {
  $period = drupal_map_assoc(array(900, 1800, 3600, 7200, 10800, 21600, 32400, 43200, 64800, 86400, 172800, 259200, 604800, 1209600, 2419200), 'format_interval');

  if ($edit['refresh'] == '') {
    $edit['refresh'] = 3600;
  }

  $form['title'] = array('#type' => 'textfield',
    '#title' => t('Title'),
    '#default_value' => $edit['title'],
    '#maxlength' => 64,
    '#description' => t('The name of the feed; typically the name of the web site you syndicate content from.'),
    '#required' => TRUE,
  );
  $form['url'] = array('#type' => 'textfield',
    '#title' => t('URL'),
    '#default_value' => $edit['url'],
    '#maxlength' => 255,
    '#description' => t('The fully-qualified URL of the feed.'),
    '#required' => TRUE,
  );
  $form['refresh'] = array('#type' => 'select',
    '#title' => t('Update interval'),
    '#default_value' => $edit['refresh'],
    '#options' => $period,
    '#description' => t('The refresh interval indicating how often you want to update this feed. Requires crontab.'),
  );

  // Handling of categories:
  $options = array();
  $values = array();
  $categories = db_query('SELECT c.cid, c.title, f.fid FROM {aggregator_category} c LEFT JOIN {aggregator_category_feed} f ON c.cid = f.cid AND f.fid = %d ORDER BY title', $edit['fid']);
  while ($category = db_fetch_object($categories)) {
    $options[$category->cid] = check_plain($category->title);
    if ($category->fid) $values[] = $category->cid;
  }
  if ($options) {
    $form['category'] = array('#type' => 'checkboxes',
      '#title' => t('Categorize news items'),
      '#default_value' => $values,
      '#options' => $options,
      '#description' => t('New items in this feed will be automatically filed in the checked categories as they are received.'),
    );
  }
  $form['submit'] = array('#type' => 'submit', '#value' => t('Submit'));

  if ($edit['fid']) {
    $form['delete'] = array('#type' => 'submit', '#value' => t('Delete'));
    $form['fid'] = array('#type' => 'hidden', '#value' => $edit['fid']);
  }

  return $form;
}

/**
 * Validate aggregator_form_feed form submissions.
 */
function aggregator_form_feed_validate($form_id, $form_values) {
  if ($form_values['op'] == t('Submit')) {
    // Check for duplicate titles
    if (isset($form_values['fid'])) {
      $result = db_query("SELECT title, url FROM {aggregator_feed} WHERE (title = '%s' OR url='%s') AND fid != %d", $form_values['title'], $form_values['url'], $form_values['fid']);
    }
    else {
      $result = db_query("SELECT title, url FROM {aggregator_feed} WHERE title = '%s' OR url='%s'", $form_values['title'], $form_values['url']);
    }
    while ($feed = db_fetch_object($result)) {
      if (strcasecmp($feed->title, $form_values['title']) == 0) {
        form_set_error('title', t('A feed named %feed already exists. Please enter a unique title.', array('%feed' => $form_values['title'])));
      }
      if (strcasecmp($feed->url, $form_values['url']) == 0) {
        form_set_error('url', t('A feed with this URL %url already exists. Please enter a unique URL.', array('%url' => $form_values['url'])));
      }
    }
  }
}

/**
 * Process aggregator_form_feed form submissions.
 * @todo Add delete confirmation dialog.
 */
function aggregator_form_feed_submit($form_id, $form_values) {
  if ($form_values['op'] == t('Delete')) {
    $title = $form_values['title'];
    // Unset the title:
    unset($form_values['title']);
  }
  aggregator_save_feed($form_values);
  menu_rebuild();
  if (isset($form_values['fid'])) {
    if (isset($form_values['title'])) {
      drupal_set_message(t('The feed %feed has been updated.', array('%feed' => $form_values['title'])));
      if (arg(0) == 'admin') {
        return 'admin/content/aggregator/';
      }
      else {
        return 'aggregator/sources/'. $form_values['fid'];
      }
    }
    else {
      watchdog('aggregator', t('Feed %feed deleted.', array('%feed' => $title)));
      drupal_set_message(t('The feed %feed has been deleted.', array('%feed' => $title)));
      if (arg(0) == 'admin') {
        return 'admin/content/aggregator/';
      }
      else {
        return 'aggregator/sources/';
      }
    }
  }
  else {
    watchdog('aggregator', t('Feed %feed added.', array('%feed' => $form_values['title'])), WATCHDOG_NOTICE, l(t('view'), 'admin/content/aggregator'));
    drupal_set_message(t('The feed %feed has been added.', array('%feed' => $form_values['title'])));
  }
}

/**
 * Add/edit/delete an aggregator feed.
 */
function aggregator_save_feed($edit) {
  if ($edit['fid']) {
    // An existing feed is being modified, delete the category listings.
    db_query('DELETE FROM {aggregator_category_feed} WHERE fid = %d', $edit['fid']);
  }
  if ($edit['fid'] && $edit['title']) {
    db_query("UPDATE {aggregator_feed} SET title = '%s', url = '%s', refresh = %d WHERE fid = %d", $edit['title'], $edit['url'], $edit['refresh'], $edit['fid']);
  }
  else if ($edit['fid']) {
    $result = db_query('SELECT iid FROM {aggregator_item} WHERE fid = %d', $edit['fid']);
    while ($item = db_fetch_object($result)) {
      $items[] = "iid = $item->iid";
    }
    if ($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', $edit['fid']);
  }
  else if ($edit['title']) {
    // A single unique id for bundles and feeds, to use in blocks.
    $edit['fid'] = db_next_id('{aggregator_feed}_fid');
    db_query("INSERT INTO {aggregator_feed} (fid, title, url, refresh, block) VALUES (%d, '%s', '%s', %d, 5)", $edit['fid'], $edit['title'], $edit['url'], $edit['refresh']);
  }
  if ($edit['title']) {
    // The feed is being saved, save the categories as well.
    if ($edit['category']) {
      foreach ($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 = $item->iid";
  }
  if ($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 = $name;
      }
    case 'LINK':
      if ($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, $tag;
  switch ($element) {
    case 'ITEM':
      $items[$item][$tag] .= $data;
      break;
    case 'IMAGE':
    case 'LOGO':
      $image[$tag] .= $data;
      break;
    case 'LINK':
      if ($data) {
        $items[$item][$tag] .= $data;
      }
      break;
    case 'CONTENT':
      $items[$item]['CONTENT'] .= $data;
      break;
    case 'SUMMARY':
      $items[$item]['SUMMARY'] .= $data;
      break;
    case 'TAGLINE':
    case 'SUBTITLE':
      $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:
      $channel[$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', t('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)) {

        if ($result->headers['Last-Modified']) {
          $modified = strtotime($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 ($image['LINK'] && $image['URL'] && $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;
        }

        /*
        ** 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, $result->headers['ETag'], $modified, $feed['fid']);

        /*
        ** Clear the cache:
        */

        cache_clear_all();

        watchdog('aggregator', t('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', t('The RSS-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 RSS-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', t('The RSS-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 RSS-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 ($item['TITLE']) {
      $title = $item['TITLE'];
    }
    else {
      $title = preg_replace('/^(.*)[^\w;&].*?$/', "\\1", truncate_utf8($item['DESCRIPTION'], 40));
    }

    /*
    ** Resolve the items link.
    */

    if ($item['LINK']) {
      $link = $item['LINK'];
    }
    else {
      $link = $feed['link'];
    }
    if ($item['GUID']) {
      $guid = $item['GUID'];
    }

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

    if ($item['PUBDATE']) $date = $item['PUBDATE'];                        // RSS 2.0
    else if ($item['DC:DATE']) $date = $item['DC:DATE'];                   // Dublin core
    else if ($item['DCTERMS:ISSUED']) $date = $item['DCTERMS:ISSUED'];     // Dublin core
    else if ($item['DCTERMS:CREATED']) $date = $item['DCTERMS:CREATED'];   // Dublin core
    else if ($item['DCTERMS:MODIFIED']) $date = $item['DCTERMS:MODIFIED']; // Dublin core
    else if ($item['ISSUED']) $date = $item['ISSUED'];                     // Atom XML
    else if ($item['CREATED']) $date = $item['CREATED'];                   // Atom XML
    else if ($item['MODIFIED']) $date = $item['MODIFIED'];                 // Atom XML
    else if ($item['PUBLISHED']) $date = $item['PUBLISHED'];               // Atom XML
    else if ($item['UPDATED']) $date = $item['UPDATED'];                   // Atom XML
    else $date = 'now';

    $timestamp = strtotime($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 it's ID such that we can update it if needed.
    */