node.module

<?php
// $Id$

/**
 * @file
 * The core that allows content to be submitted to the site.
 */

define('NODE_NEW_LIMIT', time() - 30 * 24 * 60 * 60);

/**
 * Implementation of hook_help().
 */
function node_help($section) {
  switch ($section) {
    case 'admin/help#node':
      $output = '<p>'. t('All content in a website is stored and treated as <b>nodes</b>. Therefore nodes are any postings such as blogs, stories, polls and forums. The node module manages these content types and is one of the strengths of Drupal over other content management systems.') .'</p>';
      $output .= '<p>'. t('Treating all content as nodes allows the flexibility of creating new types of content. It also allows you to painlessly apply new features or changes to all content. Comments are not stored as nodes but are always associated with a node.') .'</p>';
      $output .= t('<p>Node module features</p>
<ul>
<li>The list tab provides an interface to search and sort all content on your site.</li>
<li>The configure settings tab has basic settings for content on your site.</li>
<li>The configure content types tab lists all content types for your site and lets you configure their default workflow.</li>
<li>The search tab lets you search all content on your site</li>
</ul>
');
      $output .= t('<p>You can</p>
<ul>
<li>search for content at <a href="%search">search</a>.</li>
<li>administer nodes at <a href="%admin-node-configure-types">administer &gt;&gt; content &gt;&gt; configure &gt;&gt; content types</a>.</li>
</ul>
', array('%search' => url('search'), '%admin-node-configure-types' => url('admin/node/configure/types')));
      $output .= '<p>'. t('For more information please read the configuration and customization handbook <a href="%node">Node page</a>.', array('%node' => 'http://www.drupal.org/handbook/modules/node/')) .'</p>';
      return $output;
    case 'admin/modules#description':
      return t('Allows content to be submitted to the site and displayed on pages.');
    case 'admin/node/configure':
    case 'admin/node/configure/settings':
      return t('<p>Settings for the core of Drupal. Almost everything is a node so these settings will affect most of the site.</p>');
    case 'admin/node':
      return t('<p>Below is a list of all of the posts on your site. Other forms of content are listed elsewhere (e.g. <a href="%comments">comments</a>).</p><p>Clicking a title views the post, while clicking an author\'s name views their user information.</p>', array('%comments' => url('admin/comment')));
    case 'admin/node/search':
      return t('<p>Enter a simple pattern to search for a post. This can include the wildcard character *.<br />For example, a search for "br*" might return "bread bakers", "our daily bread" and "brenda".</p>');
  }

  if (arg(0) == 'node' && is_numeric(arg(1)) && arg(2) == 'revisions') {
    return t('The revisions let you track differences between multiple versions of a post.');
  }

  if (arg(0) == 'node' && arg(1) == 'add' && $type = arg(2)) {
    return variable_get($type .'_help', '');
  }
}

/**
 * Implementation of hook_cron().
 */
function node_cron() {
  db_query('DELETE FROM {history} WHERE timestamp < %d', NODE_NEW_LIMIT);
}

/**
 * Gather a listing of links to nodes.
 *
 * @param $result
 *   A DB result object from a query to fetch node objects.  If your query joins the <code>node_comment_statistics</code> table so that the <code>comment_count</code> field is available, a title attribute will be added to show the number of comments.
 * @param $title
 *   A heading for the resulting list.
 *
 * @return
 *   An HTML list suitable as content for a block.
 */
function node_title_list($result, $title = NULL) {
  while ($node = db_fetch_object($result)) {
    $items[] = l($node->title, 'node/'. $node->nid, $node->comment_count ? array('title' => format_plural($node->comment_count, '1 comment', '%count comments')) : '');
  }

  return theme('node_list', $items, $title);
}

/**
 * Format a listing of links to nodes.
 */
function theme_node_list($items, $title = NULL) {
  return theme('item_list', $items, $title);
}

/**
 * Update the 'last viewed' timestamp of the specified node for current user.
 */
function node_tag_new($nid) {
  global $user;

  if ($user->uid) {
    if (node_last_viewed($nid)) {
      db_query('UPDATE {history} SET timestamp = %d WHERE uid = %d AND nid = %d', time(), $user->uid, $nid);
    }
    else {
      @db_query('INSERT INTO {history} (uid, nid, timestamp) VALUES (%d, %d, %d)', $user->uid, $nid, time());
    }
  }
}

/**
 * Retrieves the timestamp at which the current user last viewed the
 * specified node.
 */
function node_last_viewed($nid) {
  global $user;
  static $history;

  if (!isset($history[$nid])) {
    $history[$nid] = db_fetch_object(db_query("SELECT timestamp FROM {history} WHERE uid = '$user->uid' AND nid = %d", $nid));
  }

  return (isset($history[$nid]->timestamp) ? $history[$nid]->timestamp : 0);
}

/**
 * Decide on the type of marker to be displayed for a given node.
 *
 * @param $nid
 *   Node ID whose history supplies the "last viewed" timestamp.
 * @param $timestamp
 *   Time which is compared against node's "last viewed" timestamp.
 * @return
 *   One of the MARK constants.
 */
function node_mark($nid, $timestamp) {
  global $user;
  static $cache;

  if (!$user->uid) {
    return MARK_READ;
  }
  if (!isset($cache[$nid])) {
    $cache[$nid] = node_last_viewed($nid);
  }
  if ($cache[$nid] == 0 && $timestamp > NODE_NEW_LIMIT) {
    return MARK_NEW;
  }
  elseif ($timestamp > $cache[$nid] && $timestamp > NODE_NEW_LIMIT) {
    return MARK_UPDATED;
  }
  return MARK_READ;
}

/**
 * Automatically generate a teaser for a node body in a given format.
 */
function node_teaser($body, $format = NULL) {

  $size = variable_get('teaser_length', 600);

  // find where the delimiter is in the body
  $delimiter = strpos($body, '<!--break-->');

  // If the size is zero, and there is no delimiter, the entire body is the teaser.
  if ($size == 0 && $delimiter == 0) {
    return $body;
  }

  // We check for the presence of the PHP evaluator filter in the current
  // format. If the body contains PHP code, we do not split it up to prevent
  // parse errors.
  if (isset($format)) {
    $filters = filter_list_format($format);
    if (isset($filters['filter/1']) && strpos($body, '<?') !== false) {
      return $body;
    }
  }

  // If a valid delimiter has been specified, use it to chop of the teaser.
  if ($delimiter > 0) {
    return substr($body, 0, $delimiter);
  }

  // If we have a short body, the entire body is the teaser.
  if (strlen($body) < $size) {
    return $body;
  }

  // In some cases, no delimiter has been specified (e.g. when posting using
  // the Blogger API). In this case, we try to split at paragraph boundaries.
  // When even the first paragraph is too long, we try to split at the end of
  // the next sentence.
  $breakpoints = array('</p>' => 4, '<br />' => 0, '<br>' => 0, "\n" => 0, '. ' => 1, '! ' => 1, '? ' => 1, '。' => 1, '؟ ' => 1);
  foreach ($breakpoints as $point => $charnum) {
    if ($length = strpos($body, $point, $size)) {
      return substr($body, 0, $length + $charnum);
    }
  }

  // If all else fails, we simply truncate the string.
  return truncate_utf8($body, $size);
}

function _node_names($op = '', $node = NULL) {
  static $node_names = array();
  static $node_list = array();

  if (empty($node_names)) {
    $node_names = module_invoke_all('node_info');
    foreach ($node_names as $type => $value) {
      $node_list[$type] = $value['name'];
    }
  }
  if ($node) {
    if (is_array($node)) {
      $type = $node['type'];
    }
    elseif (is_object($node)) {
      $type = $node->type;
    }
    elseif (is_string($node)) {
      $type = $node;
    }
    if (!isset($node_names[$type])) {
      return FALSE;
    }
  }
  switch ($op) {
    case 'base':
      return $node_names[$type]['base'];
    case 'list':
      return $node_list;
    case 'name':
      return $node_list[$type];
  }
}

/**
 * Determine the basename for hook_load etc.
 *
 * @param $node
 *   Either a node object, a node array, or a string containing the node type.
 * @return
 *   The basename for hook_load, hook_nodeapi etc.
 */
function node_get_base($node) {
  return _node_names('base', $node);
}

/**
 * Determine the human readable name for a given type.
 *
 * @param $node
 *   Either a node object, a node array, or a string containing the node type.
 * @return
 *   The human readable name of the node type.
 */
function node_get_name($node) {
  return _node_names('name', $node);
}

/**
 * Return the list of available node types.
 *
 * @param $node
 *   Either a node object, a node array, or a string containing the node type.
 * @return
 *   An array consisting ('#type' => name) pairs.
 */
function node_get_types() {
  return _node_names('list');
}

/**
 * Determine whether a node hook exists.
 *
 * @param &$node
 *   Either a node object, node array, or a string containing the node type.
 * @param $hook
 *   A string containing the name of the hook.
 * @return
 *   TRUE iff the $hook exists in the node type of $node.
 */
function node_hook(&$node, $hook) {
  return module_hook(node_get_base($node), $hook);
}

/**
 * Invoke a node hook.
 *
 * @param &$node
 *   Either a node object, node array, or a string containing the node type.
 * @param $hook
 *   A string containing the name of the hook.
 * @param $a2, $a3, $a4
 *   Arguments to pass on to the hook, after the $node argument.
 * @return
 *   The returned value of the invoked hook.
 */
function node_invoke(&$node, $hook, $a2 = NULL, $a3 = NULL, $a4 = NULL) {
  if (node_hook($node, $hook)) {
    $function = node_get_base($node) ."_$hook";
    return ($function($node, $a2, $a3, $a4));
  }
}

/**
 * Invoke a hook_nodeapi() operation in all modules.
 *
 * @param &$node
 *   A node object.
 * @param $op
 *   A string containing the name of the nodeapi operation.
 * @param $a3, $a4
 *   Arguments to pass on to the hook, after the $node and $op arguments.
 * @return
 *   The returned value of the invoked hooks.
 */
function node_invoke_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  $return = array();
  foreach (module_implements('nodeapi') as $name) {
    $function = $name .'_nodeapi';
    $result = $function($node, $op, $a3, $a4);
    if (isset($result) && is_array($result)) {
      $return = array_merge($return, $result);
    }
    else if (isset($result)) {
      $return[] = $result;
    }
  }
  return $return;
}

/**
 * Load a node object from the database.
 *
 * @param $param
 *   Either the nid of the node or an array of conditions to match against in the database query
 * @param $revision
 *   Which numbered revision to load. Defaults to the current version.
 * @param $reset
 *   Whether to reset the internal node_load cache.
 *
 * @return
 *   A fully-populated node object.
 */
function node_load($param = array(), $revision = NULL, $reset = NULL) {
  static $nodes = array();

  if ($reset) {
    $nodes = array();
  }

  if (is_numeric($param)) {
    $cachable = $revision == NULL;
    if ($cachable && isset($nodes[$param])) {
      return $nodes[$param];
    }
    $cond = 'n.nid = '. $param;
  }
  else {
    // Turn the conditions into a query.
    foreach ($param as $key => $value) {
      $cond[] = 'n.'. db_escape_string($key) ." = '". db_escape_string($value) ."'";
    }
    $cond = implode(' AND ', $cond);
  }

  // Retrieve the node.
  if ($revision) {
    $node = db_fetch_object(db_query(db_rewrite_sql('SELECT n.nid, r.vid, n.type, n.status, n.created, n.changed, n.comment, n.promote, n.moderate, n.sticky, r.timestamp AS revision_timestamp, r.title, r.body, r.teaser, r.log, r.format, u.uid, u.name, u.picture, u.data FROM {node} n INNER JOIN {users} u ON u.uid = n.uid INNER JOIN {node_revisions} r ON r.nid = n.nid AND r.vid = %d WHERE '. $cond), $revision));
  }
  else {
    $node = db_fetch_object(db_query(db_rewrite_sql('SELECT n.nid, n.vid, n.type, n.status, n.created, n.changed, n.comment, n.promote, n.moderate, n.sticky, r.timestamp AS revision_timestamp, r.title, r.body, r.teaser, r.log, r.format, u.uid, u.name, u.picture, u.data FROM {node} n INNER JOIN {users} u ON u.uid = n.uid INNER JOIN {node_revisions} r ON r.vid = n.vid WHERE '. $cond)));
  }

  if ($node->nid) {
    // Call the node specific callback (if any) and piggy-back the
    // results to the node or overwrite some values.
    if ($extra = node_invoke($node, 'load')) {
      foreach ($extra as $key => $value) {
        $node->$key = $value;
      }
    }

    if ($extra = node_invoke_nodeapi($node, 'load')) {
      foreach ($extra as $key => $value) {
        $node->$key = $value;
      }
    }
  }

  if ($cachable) {
    $nodes[$param] = $node;
  }

  return $node;
}

/**
 * Save a node object into the database.
 */
function node_save(&$node) {
  global $user;

  $node->is_new = false;

  // Apply filters to some default node fields:
  if (empty($node->nid)) {
    // Insert a new node.
    $node->is_new = true;

    // Set some required fields:
    if (!$node->created) {
      $node->created = time();
    }
    $node->nid = db_next_id('{node}_nid');
    $node->vid = db_next_id('{node_revisions}_vid');;
  }
  else {
    // We need to ensure that all node fields are filled.
    $node_current = node_load($node->nid);
    foreach ($node as $field => $data) {
      $node_current->$field = $data;
    }
    $node = $node_current;

    if ($node->revision) {
      $node->old_vid = $node->vid;
      $node->vid = db_next_id('{node_revisions}_vid');
      // We always update the timestamp for new revisions.
      $node->changed = time();
    }
  }

  if (!$node->changed) {
    $node->changed = time();
  }

  // Split off revisions data to another structure
  $revisions_table_values = array('nid' => $node->nid, 'vid' => $node->vid,
                     'title' => $node->title, 'body' => $node->body,
                     'teaser' => $node->teaser, 'log' => $node->log, 'timestamp' => $node->changed,
                     'uid' => $user->uid, 'format' => $node->format);
  $revisions_table_types = array('nid' => '%d', 'vid' => '%d',
                     'title' => "'%s'", 'body' => "'%s'",
                     'teaser' => "'%s'", 'log' => "'%s'", 'timestamp' => '%d',
                     'uid' => '%d', 'format' => '%d');
  $node_table_values = array('nid' => $node->nid, 'vid' => $node->vid,
                    'title' => $node->title, 'type' => $node->type, 'uid' => $node->uid,
                    'status' => $node->status, 'created' => $node->created,
                    'changed' => $node->changed, 'comment' => $node->comment,
                    'promote' => $node->promote, 'moderate' => $node->moderate,
                    'sticky' => $node->sticky);
  $node_table_types = array('nid' => '%d', 'vid' => '%d',
                    'title' => "'%s'", 'type' => "'%s'", 'uid' => '%d',
                    'status' => '%d', 'created' => '%d',
                    'changed' => '%d', 'comment' => '%d',
                    'promote' => '%d', 'moderate' => '%d',
                    'sticky' => '%d');

  //Generate the node table query and the
  //the node_revisions table query
  if ($node->is_new) {
    $node_query = 'INSERT INTO {node} ('. implode(', ', array_keys($node_table_types)) .') VALUES ('. implode(', ', $node_table_types) .')';
    $revisions_query = 'INSERT INTO {node_revisions} ('. implode(', ', array_keys($revisions_table_types)) .') VALUES ('. implode(', ', $revisions_table_types) .')';
  }
  else {
    $arr = array();
    foreach ($node_table_types as $key => $value) {
      $arr[] = $key .' = '. $value;
    }
    $node_table_values[] = $node->nid;
    $node_query = 'UPDATE {node} SET '. implode(', ', $arr) .' WHERE nid = %d';
    if ($node->revision) {
      $revisions_query = 'INSERT INTO {node_revisions} ('. implode(', ', array_keys($revisions_table_types)) .') VALUES ('. implode(', ', $revisions_table_types) .')';
    }
    else {
      $arr = array();
      foreach ($revisions_table_types as $key => $value) {
        $arr[] = $key .' = '. $value;
      }
      $revisions_table_values[] = $node->vid;
      $revisions_query = 'UPDATE {node_revisions} SET '. implode(', ', $arr) .' WHERE vid = %d';
    }
  }

  // Insert the node into the database:
  db_query($node_query, $node_table_values);
  db_query($revisions_query, $revisions_table_values);

  // Call the node specific callback (if any):
  if ($node->is_new) {
    node_invoke($node, 'insert');
    node_invoke_nodeapi($node, 'insert');
  }
  else {
    node_invoke($node, 'update');
    node_invoke_nodeapi($node, 'update');
  }

  // Clear the cache so an anonymous poster can see the node being added or updated.
  cache_clear_all();
}

/**
 * Generate a display of the given node.
 *
 * @param $node
 *   A node array or node object.
 * @param $teaser
 *   Whether to display the teaser only, as on the main page.
 * @param $page
 *   Whether the node is being displayed by itself as a page.
 * @param $links
 *   Whether or not to display node links. Links are omitted for node previews.
 *
 * @return
 *   An HTML representation of the themed node.
 */
function node_view($node, $teaser = FALSE, $page = FALSE, $links = TRUE) {
  $node = array2object($node);

  // Remove the delimiter (if any) that separates the teaser from the body.
  // TODO: this strips legitimate uses of '<!--break-->' also.
  $node->body = str_replace('<!--break-->', '', $node->body);

  if ($node->log != '' && !$teaser && $node->moderate) {
    $node->body .= '<div class="log"><div class="title">'. t('Log') .':</div>'. $node->log .'</div>';
  }

  // The 'view' hook can be implemented to overwrite the default function
  // to display nodes.
  if (node_hook($node, 'view')) {
    node_invoke($node, 'view', $teaser, $page);
  }
  else {
    $node = node_prepare($node, $teaser);
  }
  // Allow modules to change $node->body before viewing.
  node_invoke_nodeapi($node, 'view', $teaser, $page);
  if ($links) {
    $node->links = module_invoke_all('link', 'node', $node, !$page);
  }
  // unset unused $node part so that a bad theme can not open a security hole
  if ($teaser) {
    unset($node->body);
  }
  else {
    unset($node->teaser);
  }

  return theme('node', $node, $teaser, $page);
}

/**
 * Apply filters to a node in preparation for theming.
 */
function node_prepare($node, $teaser = FALSE) {
  $node->readmore = (strlen($node->teaser) < strlen($node->body));
  if ($teaser == FALSE) {
    $node->body = check_markup($node->body, $node->format, FALSE);
  }
  else {
    $node->teaser = check_markup($node->teaser, $node->format, FALSE);
  }
  return $node;
}

/**
 * Generate a page displaying a single node, along with its comments.
 */
function node_show($node, $cid) {
  $output = node_view($node, FALSE, TRUE);

  if (function_exists('comment_render') && $node->comment) {
    $output .= comment_render($node, $cid);
  }

  // Update the history table, stating that this user viewed this node.
  node_tag_new($node->nid);

  return $output;
}

/**
 * Implementation of hook_perm().
 */
function node_perm() {
  return array('administer nodes', 'access content');
}

/**
 * Implementation of hook_search().
 */
function node_search($op = 'search', $keys = null) {
  switch ($op) {
    case 'name':
      return t('content');

    case 'reset':
      variable_del('node_cron_last');
      return;

    case 'status':
      $last = variable_get('node_cron_last', 0);
      $total = db_result(db_query('SELECT COUNT(*) FROM {node} WHERE status = 1 AND moderate = 0'));
      $remaining = db_result(db_query('SELECT COUNT(*) FROM {node} n LEFT JOIN {node_comment_statistics} c ON n.nid = c.nid WHERE n.status = 1 AND n.moderate = 0 AND (n.created > %d OR n.changed > %d OR c.last_comment_timestamp > %d)', $last, $last, $last));
      return array('remaining' => $remaining, 'total' => $total);

    case 'admin':
      $form = array();
      // Output form for defining rank factor weights.
      $form['content_ranking'] = array('#type' => 'fieldset', '#title' => t('Content ranking'));
      $form['content_ranking']['#theme'] = 'node_search_admin';
      $form['content_ranking']['info'] = array('#type' => 'markup', '#value' => '<em>'. t('The following numbers control which properties the content search should favor when ordering the results. Higher numbers mean more influence. Zero means the property is ignored.') .'</em>');

      $ranking = array('node_rank_relevance' => t('Keyword relevance'),
                       'node_rank_recent' => t('Recently posted'));
      if (module_exist('comment')) {
        $ranking['node_rank_comments'] = t('Number of comments');
      }
      if (module_exist('statistics') && variable_get('statistics_count_content_views', 0)) {
        $ranking['node_rank_views'] = t('Number of views');
      }

      // Note: reversed to reflect that higher number = higher ranking.
      $options = drupal_map_assoc(range(0, 10));
      foreach ($ranking as $var => $title) {
        $form['content_ranking']['factors'][$var] = array('#title' => $title, '#type' => 'select', '#options' => $options, '#default_value' => variable_get($var, 5));
      }
      return $form;

    case 'search':
      // Build matching conditions
      list($join1, $where1) = _db_rewrite_sql();
      $arguments1 = array();
      $conditions1 = 'n.status = 1';

      if ($type = search_query_extract($keys, 'type')) {
        $types = array();
        foreach (explode(',', $type) as $t) {
          $types[] = "n.type = '%s'";
          $arguments1[] = $t;
        }
        $conditions1 .= ' AND ('. implode(' OR ', $types) .')';
        $keys = search_query_insert($keys, 'type');
      }

      if ($category = search_query_extract($keys, 'category')) {
        $categories = array();
        foreach (explode(',', $category) as $c) {
          $categories[] = "tn.tid = %d";
          $arguments1[] = $c;
        }
        $conditions1 .= ' AND ('. implode(' OR ', $categories) .')';
        $join1 .= ' INNER JOIN {term_node} tn ON n.nid = tn.nid';
        $keys = search_query_insert($keys, 'category');
      }

      // Build ranking expression (we try to map each parameter to a
      // uniform distribution in the range 0..1).
      $ranking = array();
      $arguments2 = array();
      $join2 = '';
      // Used to avoid joining on node_comment_statistics twice
      $stats_join = false;
      if ($weight = (int)variable_get('node_rank_relevance', 5)) {
        // Average relevance values hover around 0.15
        $ranking[] = '%d * i.relevance';
        $arguments2[] = $weight;
      }
      if ($weight = (int)variable_get('node_rank_recent', 5)) {
        // Exponential decay with half-life of 6 months, starting at last indexed node
        $ranking[] = '%d * POW(2, (GREATEST(n.created, n.changed, c.last_comment_timestamp) - %d) * 6.43e-8)';
        $arguments2[] = $weight;
        $arguments2[] = (int)variable_get('node_cron_last', 0);
        $join2 .= ' INNER JOIN {node} n ON n.nid = i.sid LEFT JOIN {node_comment_statistics} c ON c.nid = i.sid';
        $stats_join = true;
      }
      if (module_exist('comment') && $weight = (int)variable_get('node_rank_comments', 5)) {
        // Inverse law that maps the highest reply count on the site to 1 and 0 to 0.
        $scale = variable_get('node_cron_comments_scale', 0.0);
        $ranking[] = '%d * (2.0 - 2.0 / (1.0 + c.comment_count * %f))';
        $arguments2[] = $weight;
        $arguments2[] = $scale;
        if (!$stats_join) {
          $join2 .= ' LEFT JOIN {node_comment_statistics} c ON c.nid = i.sid';
        }
      }
      if (module_exist('statistics') && variable_get('statistics_count_content_views', 0) &&
          $weight = (int)variable_get('node_rank_views', 5)) {
        // Inverse law that maps the highest view count on the site to 1 and 0 to 0.
        $scale = variable_get('node_cron_views_scale', 0.0);
        $ranking[] = '%d * (2.0 - 2.0 / (1.0 + nc.totalcount * %f))';
        $arguments2[] = $weight;
        $arguments2[] = $scale;
        $join2 .= ' LEFT JOIN {node_counter} nc ON n.nid = nc.nid';
      }
      $select2 = (count($ranking) ? implode(' + ', $ranking) : 'i.relevance') . ' AS score';

      // Do search
      $find = do_search($keys, 'node', 'INNER JOIN {node} n ON n.nid = i.sid '. $join1 .' INNER JOIN {users} u ON n.uid = u.uid', $conditions1 . (empty($where1) ? '' : ' AND '. $where1), $arguments1, $select2, $join2, $arguments2);

      // Load results
      $results = array();
      foreach ($find as $item) {
        $node = node_load($item);

        // Get node output (filtered and with module-specific fields).
        if (node_hook($node, 'view')) {
          node_invoke($node, 'view', false, false);
        }
        else {
          $node = node_prepare($node, false);
        }
        // Allow modules to change $node->body before viewing.
        node_invoke_nodeapi($node, 'view', false, false);

        // Fetch comments for snippet
        $node->body .= module_invoke('comment', 'nodeapi', $node, 'update index');

        $extra = node_invoke_nodeapi($node, 'search result');
        $results[] = array('link' => url('node/'. $item),
                           'type' => node_get_name($node),
                           'title' => $node->title,
                           'user' => theme('username', $node),
                           'date' => $node->changed,
                           'node' => $node,
                           'extra' => $extra,
                           'snippet' => search_excerpt($keys, $node->body));
      }
      return $results;

    case 'form':
      $form = array();

      // Keyword boxes
      $form['advanced'] = array('#type' => 'fieldset', '#title' => t('Advanced search'), '#collapsible' => TRUE, '#collapsed' => TRUE, '#attributes' => array('class' => 'search-advanced'));

      $form['advanced']['keywords'] = array('#type' => 'markup', '#prefix' => '<div class="criterium">', '#suffix' => '</div>');
      $form['advanced']['keywords']['or'] = array('#type' => 'textfield', '#title' => t('Containing any of the words'), '#size' => 30, '#maxlength' => 255);
      $form['advanced']['keywords']['phrase'] = array('#type' => 'textfield', '#title' => t('Containing the phrase'), '#size' => 30, '#maxlength' => 255);
      $form['advanced']['keywords']['negative'] = array('#type' => 'textfield', '#title' => t('Containing none of the words'), '#size' => 30, '#maxlength' => 255);

      // Taxonomy box
      if ($taxonomy = module_invoke('taxonomy', 'form_all')) {
        $form['advanced']['category'] = array('#type' => 'select', '#title' => t('Only in the category'), '#prefix' => '<div class="criterium">', '#suffix' => '</div>', '#options' => $taxonomy, '#extra' => 'size="10"', '#multiple' => true);
      }

      // Node types
      $types = node_get_types();
      $form['advanced']['type'] = array('#type' => 'checkboxes', '#title' => t('Only of the type'), '#prefix' => '<div class="criterium">', '#suffix' => '</div>', '#options' => $types, '#multiple' => true);
      $form['advanced']['submit'] = array('#type' => 'submit', '#value' => t('Advanced Search'), '#prefix' => '<div class="action">', '#suffix' => '</div>');
      return $form;

    case 'post':
      // Insert extra restrictions into the search keywords string.
      $edit = &$_POST['edit'];
      if (isset($edit['type']) && is_array($edit['type'])) {
        $keys = search_query_insert($keys, 'type', implode(',', array_keys($edit['type'])));
      }
      if (isset($edit['category']) && is_array($edit['category'])) {
        $keys = search_query_insert($keys, 'category', implode(',', $edit['category']));
      }
      if ($edit['or'] != '') {
        if (preg_match_all('/ ("[^"]+"|[^" ]+)/i', ' '. $edit['or'], $matches)) {
          $keys = $keys .' '. implode(' OR ', $matches[1]);
        }
      }
      if ($edit['negative'] != '') {
        if (preg_match_all('/ ("[^"]+"|[^" ]+)/i', ' '. $edit['negative'], $matches)) {
          $keys = $keys .' -'. implode(' -', $matches[1]);
        }
      }
      if ($edit['phrase'] != '') {
        $keys .= ' "'. str_replace('"', ' ', $edit['phrase']) .'"';
      }
      return trim($keys);
  }
}

function theme_node_search_admin($form) {
  $output = form_render($form['info']);

  $header = array(t('Factor'), t('Weight'));
  foreach (element_children($form['factors']) as $key) {
    $row = array();
    $row[] = $form['factors'][$key]['#title'];
    unset($form['factors'][$key]['#title']);
    $row[] = form_render($form['factors'][$key]);
    $rows[] = $row;
  }
  $output .= theme('table', $header, $rows);

  $output .= form_render($form);
  return $output;
}

/**
 * Menu callback; presents general node configuration options.
 */
function node_configure() {

  $form['default_nodes_main'] = array(
    '#type' => 'select', '#title' => t('Number of posts on main page'), '#default_value' => variable_get('default_nodes_main', 10),
    '#options' =>  drupal_map_assoc(array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30)),
    '#description' => t('The default maximum number of posts to display per page on overview pages such as the main page.')
  );

  $form['teaser_length'] = array(
    '#type' => 'select', '#title' => t('Length of trimmed posts'), '#default_value' => variable_get('teaser_length', 600),
    '#options' => array(0 => t('Unlimited'), 200 => t('200 characters'), 400 => t('400 characters'), 600 => t('600 characters'),
      800 => t('800 characters'), 1000 => t('1000 characters'), 1200 => t('1200 characters'), 1400 => t('1400 characters'),
      1600 => t('1600 characters'), 1800 => t('1800 characters'), 2000 => t('2000 characters')),
    '#description' => t("The maximum number of characters used in the trimmed version of a post.  Drupal will use this setting to determine at which offset long posts should be trimmed.  The trimmed version of a post is typically used as a teaser when displaying the post on the main page, in XML feeds, etc.  To disable teasers, set to 'Unlimited'. Note that this setting will only affect new or updated content and will not affect existing teasers.")
  );

  $form['node_preview'] = array(
    '#type' => 'radios', '#title' => t('Preview post'), '#default_value' => variable_get('node_preview', 0),
    '#options' => array(t('Optional'), t('Required')), '#description' => t('Must users preview posts before submitting?')
  );

  return system_settings_form('node_configure', $form);
}

/**
 * Retrieve the comment mode for the given node ID (none, read, or read/write).
 */
function node_comment_mode($nid) {
  static $comment_mode;
  if (!isset($comment_mode[$nid])) {
    $comment_mode[$nid] = db_result(db_query('SELECT comment FROM {node} WHERE nid = %d', $nid));
  }
  return $comment_mode[$nid];
}

/**
 * Implementation of hook_link().
 */
function node_link($type, $node = 0, $main = 0) {
  $links = array();

  if ($type == 'node') {
    if (array_key_exists('links', $node)) {
      $links = $node->links;
    }

    if ($main == 1 && $node->teaser && $node->readmore) {
      $links[] = l(t('read more'), "node/$node->nid", array('title' => t('Read the rest of this posting.'), 'class' => 'read-more'));
    }
  }

  return $links;
}

/**
 * Implementation of hook_menu().
 */
function node_menu($may_cache) {
  $items = array();

  if ($may_cache) {
    $items[] = array('path' => 'admin/node', 'title' => t('content'),
      'callback' => 'node_admin_nodes',
      'access' => user_access('administer nodes'));
    $items[] = array('path' => 'admin/node/overview', 'title' => t('list'),
      'type' => MENU_DEFAULT_LOCAL_TASK, 'weight' => -10);
    $items[] = array('path' => 'admin/node/action', 'title' => t('content'),
      'callback' => 'node_admin_nodes',
      'type' => MENU_CALLBACK);

    if (module_exist('search')) {
      $items[] = array('path' => 'admin/node/search', 'title' => t('search'),
        'callback' => 'node_admin_search',
        'access' => user_access('administer nodes'),
        'type' => MENU_LOCAL_TASK);
    }

    $items[] = array('path' => 'admin/settings/node', 'title' => t('posts'),
      'callback' => 'node_configure',
      'access' => user_access('administer nodes'));
    $items[] = array('path' => 'admin/settings/content-types', 'title' => t('content types'),
      'callback' => 'node_types_configure',
      'access' => user_access('administer nodes'));

    $items[] = array('path' => 'node', 'title' => t('content'),
      'callback' => 'node_page',
      'access' => user_access('access content'),
      'type' => MENU_SUGGESTED_ITEM);
    $items[] = array('path' => 'node/add', 'title' => t('create content'),
      'callback' => 'node_page',
      'access' => user_access('access content'),
      'type' => MENU_ITEM_GROUPING,
      'weight' => 1);
    $items[] = array('path' => 'rss.xml', 'title' => t('rss feed'),
      'callback' => 'node_feed',
      'access' => user_access('access content'),
      'type' => MENU_CALLBACK);
  }
  else {
    if (arg(0) == 'node' && is_numeric(arg(1))) {
      $node = node_load(arg(1));
      if ($node->nid) {
        $items[] = array('path' => 'node/'. arg(1), 'title' => t('view'),
          'callback' => 'node_page',
          'access' => node_access('view', $node),
          'type' => MENU_CALLBACK);
        $items[] = array('path' => 'node/'. arg(1) .'/view', 'title' => t('view'),
            'type' => MENU_DEFAULT_LOCAL_TASK, 'weight' => -10);
        $items[] = array('path' => 'node/'. arg(1) .'/edit', 'title' => t('edit'),
          'callback' => 'node_page',
          'access' => node_access('update', $node),
          'weight' => 1,
          'type' => MENU_LOCAL_TASK);
        $items[] = array('path' => 'node/'. arg(1) .'/delete', 'title' => t('delete'),
          'callback' => 'node_delete_confirm',
          'access' => node_access('delete', $node),
          'weight' => 1,
          'type' => MENU_CALLBACK);
        if (user_access('administer nodes') && db_result(db_query('SELECT COUNT(vid) FROM {node_revisions} WHERE nid = %d', arg(1))) > 1) {
          $items[] = array('path' => 'node/'. arg(1) .'/revisions', 'title' => t('revisions'),
            'callback' => 'node_page',
            'access' => user_access('administer nodes'),
            'weight' => 2,
            'type' => MENU_LOCAL_TASK);
        }
      }
    }
    else if (arg(0) == 'admin' && arg(1) == 'settings' && arg(2) == 'content-types' && is_string(arg(3))) {
      $items[] = array('path' => 'admin/settings/content-types/'. arg(3),
        'title' => t("'%name' content type", array('%name' => node_get_name(arg(3)))),
        'type' => MENU_CALLBACK);
    }
  }

  return $items;
}

function node_last_changed($nid) {
  $node = db_fetch_object(db_query('SELECT changed FROM {node} WHERE nid = %d', $nid));
  return ($node->changed);
}

/*
** Node operations
*/
function node_operations() {
  $operations = array(
    'approve' =>   array(t('Approve the selected posts'), 'UPDATE {node} SET status = 1, moderate = 0 WHERE nid = %d'),
    'promote' =>   array(t('Promote the selected posts'), 'UPDATE {node} SET status = 1, promote = 1 WHERE nid = %d'),
    'sticky' =>    array(t('Make the selected posts sticky'), 'UPDATE {node} SET status = 1, sticky = 1 WHERE nid = %d'),
    'demote' =>    array(t('Demote the selected posts'), 'UPDATE {node} SET promote = 0 WHERE nid = %d'),
    'unpublish' => array(t('Unpublish the selected posts'), 'UPDATE {node} SET status = 0 WHERE nid = %d'),
    'delete' =>    array(t('Delete the selected posts'), '')
  );
  return $operations;
}

/*
** Filters
*/
function node_filters() {
  // Regular filters
  $filters = array(
    'status'   => array('title' => t('status'),
                        'options' => array('status-1'   => t('published'),     'status-0' => t('not published'),
                                           'moderate-1' => t('in moderation'), 'moderate-0' => t('not in moderation'),
                                           'promote-1'  => t('promoted'),      'promote-0' => t('not promoted'),
                                           'sticky-1'   => t('sticky'),        'sticky-0' => t('not sticky'))),
    'type'     => array('title' => t('type'), 'where' => "n.type = '%s'",
                        'options' => node_get_types()));
  // Merge all vocabularies into one for retrieving $value below
  if ($taxonomy = module_invoke('taxonomy', 'form_all')) {
    $terms = array();
    foreach ($taxonomy as $value) {
      $terms = $terms + $value;
    }
    $filters['category'] = array('title' => t('category'), 'where' => 'tn.tid = %d',
                                 'options' => $terms, 'join' => 'INNER JOIN {term_node} tn ON n.nid = tn.nid');
  }
  if (isset($filters['category'])) {
    $filters['category']['options'] = $taxonomy;
  }

  return $filters;
}

function node_build_filter_query() {
  $filters = node_filters();

  // Build query
  $where = $args = array();
  $join = '';
  foreach ($_SESSION['node_overview_filter'] as $filter) {
    list($key, $value) = $filter;
    if ($key == 'status') {
      // Note: no exploit hole as $value has already been checked
      list($key, $value) = explode('-', $value, 2);
      $where[] = 'n.'. $key .' = %d';
    }
    else {
      $where[] = $filters[$key]['where'];
    }
    $args[] = $value;
    $join .= $filters[$key]['join'];
  }
  $where = count($where) ? 'WHERE '. implode(' AND ', $where) : '';

  return array('where' => $where, 'join' => $join, 'args' => $args);
}

function node_filter_form() {
  $session = &$_SESSION['node_overview_filter'];
  $session = is_array($session) ? $session : array();
  $filters = node_filters();

  $i = 0;
  $form['filters'] = array('#type' => 'fieldset', '#title' => t('Show only items where'), '#theme' => 'node_filters');
  foreach ($session as $filter) {
    list($type, $value) = $filter;
    $string = ($i++ ? '<em>and</em> where <strong>%a</strong> is <strong>%b</strong>' : '<strong>%a</strong> is <strong>%b</strong>');
    $form['filters']['current'][] = array('#value' => t($string, array('%a' => $filters[$type]['title'] , '%b' => $filters[$type]['options'][$value])));
  }

  foreach ($filters as $key => $filter) {
    $names[$key] = $filter['title'];
    $form['filters']['status'][$key] = array('#type' => 'select', '#options' => $filter['options']);
  }

  $form['filters']['filter'] = array('#type' => 'radios', '#options' => $names, '#default_value' => 'status');
  $form['filters']['buttons']['submit'] = array('#type' => 'submit', '#value' => (count($session) ? t('Refine') : t('Filter')));
  if (count($session)) {
    $form['filters']['buttons']['undo'] = array('#type' => 'submit', '#value' => t('Undo'));
    $form['filters']['buttons']['reset'] = array('#type' => 'submit', '#value' => t('Reset'));
  }

  return drupal_get_form('node_filter_form', $form);
}

function theme_node_filter_form(&$form) {
  $output .= '<div id="node-admin-filter">';
  $output .= form_render($form['filters']);
  $output .= '</div>';
  $output .= form_render($form);
  return $output;
}

function theme_node_filters(&$form) {
  $output .= '<ul>';
  if (sizeof($form['current'])) {
    foreach (element_children($form['current']) as $key) {
      $output .= '<li>' . form_render($form['current'][$key]) . '</li>';
    }
  }

  $output .= '<li><dl class="multiselect">' . (sizeof($form['current']) ? '<dt><em>and</em> where</dt>' : '') . '<dd class="a">';
  foreach(element_children($form['filter']) as $key) {
    $output .= form_render($form['filter'][$key]);
  }
  $output .= '</dd>';

  $output .= '<dt>is</dt>' . '<dd class="b">';

  foreach(element_children($form['status']) as $key) {
    $output .= form_render($form['status'][$key]);
  }
  $output .= '</dd>';


  $output .= '</dl>';
  $output .= '<div class="container-inline" id="node-admin-buttons">'. form_render($form['buttons']) .'</div>';
  $output .= '</li></ul><br class="clear" />';

  return $output;
}


function node_filter_form_submit() {