drupal/modules/forum/forum.module

<?php
// $Id$

function forum_help($section = 'admin/help#forum') {
  $output = '';

  switch ($section) {
    case 'admin/help#forum':
      $output = t("
      <h3>Creating a forum</h3>
      <p>The forum module uses taxonomy to organize itself. To create a forum you first have to create a <a href=\"%taxonomy\">taxonomy vocabulary</a>. When doing this, choose a sensible name for it (such as \"fora\") and make sure under \"Types\" that \"forum\" is selected. Once you have done this, <a href=\"%taxo-terms\">add some terms</a> to it. Each term will become a forum. If you fill in the description field, users will be given additonal information about the forum on the main forum page. For example: \"troubleshooting\" - \"Please ask your questions here.\"</p>
      <p>When you are happy with your vocabulary, go to <a href=\"%forums\">administer &raquo; configutation &raquo; modules &raquo; forum</a> and set <strong>Forum vocabulary</strong> to the one you have just created. There will now be fora active on the site. For users to access them they must have the \"access content\" <a href=\"%permission\">permission</a> and to create a topic they must have the \"create forum topics\" <a href=\"%permission\">permission</a>. These permissions can be set in the <a href=\"%permission\">permission</a> pages.</p>
      <h4>Icons</h4>
      <p>To disable icons, set the icon path as blank in <a href=\"%forums\">administer &raquo; configutation &raquo; modules &raquo; forum</a>.</p>
      <p>All files in the icon directory are assumed to be images. You may use images of whatever size you wish, but it is recommended to use 15x15 or 16x16.</p>", array("%taxonomy" => url("admin/taxonomy/add/vocabulary"), "%taxo-terms" => url("admin/taxonomy"), "%forums" => url("admin/system/modules/forum"), "%permission" => url("admin/user/permission")));
      break;
    case 'admin/system/modules#description':
      $output = t('Enable threaded discussions about general topics.');
      break;
    case 'admin/system/modules/forum':
      $output = t("Forums are threaded discussions based on the taxonomy system.  For the forums to work, the taxonomy module has to be installed and enabled.  When activated, a taxonomy vocabulary (eg. \"forums\") needs to be <a href=\"%created\">created</a> and bound to the node type \"forum topic\".", array('%created' => url('admin/taxonomy/add/vocabulary')));
      break;
    case 'node/add/forum':
      $output = variable_get('forum_help', '');
      break;
    case 'node/add#forum':
      $output = t('A forum is a threaded discussion, enabling users to communicate about a particular topic.');
      break;
  }

  return $output;
}

function forum_node_name($node) {
  return t('forum topic');
}

function forum_access($op, $node) {
  if ($op == 'view') {
    return $node->status;
  }
  if ($op == 'create') {
    return user_access('create forum topics');
  }
}

function forum_perm() {
  return array('create forum topics');
}

function forum_settings() {

  if (module_exist('taxonomy')) {
    $vocs[0] = '<'. t('none') .'>';
    foreach (taxonomy_get_vocabularies('forum') as $vid => $voc) {
      $vocs[$vid] = $voc->name;
    }

    if ($voc) {
      $group  = form_select(t('Forum vocabulary'), 'forum_nav_vocabulary', variable_get('forum_nav_vocabulary', ''), $vocs, t("The taxonomy vocabulary that will be used as the navigation tree.  The vacabulary's terms define the forums."));
      $group .= _taxonomy_term_select(t('Containers'), 'forum_containers', variable_get('forum_containers', array()), variable_get('forum_nav_vocabulary', ''), t('You can choose forums which will not have topics, but will be just containers for other forums.  This lets you both group and nest forums.'), 1, '<'. t('none') .'>');

      $output = form_group(t('Forum structure settings'), $group);

      $group  = form_textarea(t('Explanation or submission guidelines'), 'forum_help', variable_get('forum_help', ''), 70, 5, t('This text will be displayed at the top of the forum submission form.  Useful for helping or instructing your users.'));
      $group .= form_textfield(t('Forum icon path'), 'forum_icon_path', variable_get('forum_icon_path', ''), 30, 255, t("The path to the forum icons.  Leave blank to disable icons.  Don't add a trailing slash.  Default icons are available in the 'misc' directory."));
      $number = drupal_map_assoc(array(5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 80, 100, 10000));
      $group .= form_select(t('Hot topic threshold'), 'forum_hot_topic', variable_get('forum_hot_topic', 15), $number, t('The number of posts a topic must have to be considered <strong>hot</strong>.'));
      $number = drupal_map_assoc(array(10, 25, 50, 75, 100));
      $group .= form_select(t('Topics per page'), 'forum_per_page', variable_get('forum_per_page', 25), $number, t('The default number of topics displayed per page; links to browse older messages are automatically being displayed.'));
      $forder = array(1 => t('Date - newest first'), 2 => t('Date - oldest first'), 3 => t('Posts - most active first'), 4=> t('Posts - least active first'));
      $group .= form_radios(t('Default order'), 'forum_order', variable_get('forum_order', '1'), $forder, t('The default display order for topics.'));
      $output .= form_group(t('Forum viewing options'), $group);

      $group = form_textfield(t('Number of topics in block'), 'forum_block_num', variable_get('forum_block_num', '5'), 5, 5, t("The number of topics to show in the \"Forum topics\" block.  To enable the block, go to the <a href=\"%block-administration\">block administration</a> page.", array('%block-administration' => url('admin/system/block'))));
      $output .= form_group(t('"Forum topic" block settings'), $group);
    }
  }

  return $output;
}

function forum_taxonomy($op, $type, $object) {
  if ($type == 'vocabulary' && ($op == 'insert' || $op == 'update')) {
    if (variable_get('forum_nav_vocabulary', '') == '' && in_array('forum', $object['nodes'])) {
      // since none is already set, silently set this vocabulary as the navigation vocabulary
      variable_set('forum_nav_vocabulary', $object['vid']);
    }
  }
}

function forum_load($node) {
  $forum = db_fetch_object(db_query('SELECT * FROM {forum} WHERE nid = %d', $node->nid));

  return $forum;
}

function forum_block($op = 'list', $delta = 0) {
  if ($op == 'list') {
    $blocks[0]['info'] = t('Forum topics');
  }
  else {
    if (user_access('access content')) {
      $content = node_title_list(db_query_range("SELECT n.nid, n.title, GREATEST(n.created, MAX(c.timestamp)) AS sort FROM {node} n LEFT JOIN {comments} c ON n.nid = c.nid WHERE n.type = 'forum' AND n.status = 1 GROUP BY n.nid, n.title, n.created ORDER BY sort DESC", 0, variable_get('forum_block_num', '5')), t('Active forum topics:'));

      $content .= node_title_list(db_query_range("SELECT nid, title FROM {node} WHERE type = 'forum' AND status = 1 ORDER BY nid DESC", 0, variable_get('forum_block_num', '5')), t('New forum topics:'));

      if ($content) {
        $content .= "<div class=\"more-link\">". l(t('more'), 'forum', array('title' => t('Read the latest forum topics.'))) .'</div>';
      }

      $blocks['subject'] = t('Forum topics');
      $blocks['content'] = $content;
    }
  }

  return $blocks;
}

function forum_link($type, $node = 0, $main = 0) {
  global $user;

  $links = array();

  if ($type == 'page' && user_access('access content')) {
    $links[] = l(t('forums'), 'forum');
  }

  if ($type == 'system') {
    if (user_access('create forum topics')) {
      menu('node/add/forum', t('forum topic'), 'node_page');
    }
    if (user_access('access content')) {
      menu('forum', t('forums'), 'forum_page', 0, MENU_HIDE);
    }
  }

  if (!$main && $type == 'node' && $node->type == 'forum') {
    // get previous and next topic

    $result = db_query('SELECT n.nid, n.title, GREATEST(n.created, MAX(c.timestamp)) AS date_sort, COUNT(c.nid) AS num_comments FROM {node} n INNER JOIN {forum} f ON n.nid = f.nid INNER JOIN {comments} c ON n.nid = c.nid WHERE n.nid = f.nid AND f.tid = %d AND n.status = 1 GROUP BY n.nid, n.title, n.created ORDER BY '. _forum_get_topic_order(isset($user->sortby) ? $user->sortby : variable_get('forum_order', 1)), $node->tid);

    while ($topic = db_fetch_object($result)) {
      if ($stop == 1) {
        $next->nid = $topic->nid;
        $next->title = $topic->title;
        break;
      }
      if ($topic->nid == $node->nid) {
        $stop = 1;
      }
      else {
        $prev->nid = $topic->nid;
        $prev->title = $topic->title;
      }
    }

    if ($prev) {
      $links[] = l(t('previous forum topic'), "node/view/$prev->nid", array('title' => $prev->title));
    }

    if ($next) {
      $links[] = l(t('next forum topic'), "node/view/$next->nid", array('title' => $next->title));
    }
  }

  return $links;
}

function forum_content($node, $main = 0) {
  return node_prepare($node, $main);
}

function forum_view($node, $main = 0, $page = 0) {

  if ($page) {
    $vocabulary = taxonomy_get_vocabulary(variable_get('forum_nav_vocabulary', ''));
    // Breadcrumb navigation
    $breadcrumb = array(l(t('Home'), NULL), l($vocabulary->name, 'forum'));
    if ($parents = taxonomy_get_parents_all($node->tid)) {
      $parents = array_reverse($parents);
      foreach ($parents as $p) {
        $breadcrumb[] = l($p->name, "forum/$p->tid");
      }
    }
    drupal_set_breadcrumb($breadcrumb);
  }

  return theme('node', forum_content($node, $main), $main, $page);
}

function forum_validate(&$node) {
  // Make sure all fields are set properly:
  $node->icon = $node->icon ? $node->icon : '';
  $node->shadow = $node->shadow ? $node->shadow : 0;

  if ($node->taxonomy) {
    // Extract the node's proper topic ID.
    $vocabulary = variable_get('forum_nav_vocabulary', '');
    $containers = variable_get('forum_containers', array());
    foreach ($node->taxonomy as $term) {
      if (db_result(db_query('SELECT COUNT(*) FROM {term_data} WHERE tid = %d AND vid = %d', $term, $vocabulary))) {
        if (in_array($term, $containers)) {
          $term = taxonomy_get_term($term);
          $error['taxonomy'] = theme('error', t('The item \'%forum\' is only a container for forums. Please select one of the forums below it.', array('%forum' => $term->name)));
        }
        else {
          $node->tid = $term;
        }
      }
    }
  }
  return $error;
}

function forum_form(&$node, &$error) {
  if (!$node->nid) {
    // new topic
    $node->taxonomy[] = arg(3);
  }

  $output = implode('', taxonomy_node_form('forum', $node, $error));

  if ($node->nid) {
    // if editing, give option to leave shadows
    $output .= form_checkbox(t('Leave shadow copy'), 'shadow', 1, $node->shadow, t('If you move this topic, you can leave a link in the old forum to the new forum.'));
  }

  $output .= form_textarea(t('Body'), 'body', $node->body, 60, 10, filter_tips_short());

  return $output;
}

function forum_insert($node) {
  db_query('INSERT INTO {forum} (nid, shadow, tid) VALUES (%d, %d, %d)', $node->nid, $node->shadow, $node->tid);
}

function forum_update($node) {
  db_query('UPDATE {forum} SET shadow = %d, tid = %d WHERE nid = %d', $node->shadow, $node->tid, $node->nid);
}

function forum_delete(&$node) {
  db_query('DELETE FROM {forum} WHERE nid = %d', $node->nid);
}

function _forum_num_comments($nid) {
  $value = db_fetch_object(db_query('SELECT COUNT(cid) AS count FROM {comments} WHERE nid = %d AND status = 0', $nid));
  return ($value) ? $value->count : 0;
}

function _forum_last_comment($nid) {
  $value = db_fetch_object(db_query_range('SELECT timestamp FROM {comments} WHERE nid = %d AND status = 0 ORDER BY timestamp DESC', $nid, 0, 1));
  return ($value) ? format_date($value->timestamp, 'small') : '&nbsp;';
}

function _forum_last_reply($nid) {
  $value = db_fetch_object(db_query_range('SELECT c.timestamp, u.name, u.uid FROM {comments} c INNER JOIN {users} u ON c.uid = u.uid WHERE c.nid = %d AND c.status = 0 ORDER BY c.timestamp DESC', $nid, 0, 1));
  return $value;
}

function _forum_format($topic) {
  if ($topic) {
    return t('%time ago<br />by %author', array('%time' => format_interval(time() - $topic->timestamp), '%author' => format_name($topic)));
  }
  else {
    return message_na();
  }
}

function forum_get_forums($tid = 0) {
  global $user;

  if (!$tid) {
    $tid = 0;
  }

  $cache = cache_get("forum:$tid");

  if (empty($cache)) {
    $forums = array();
    $_forums = taxonomy_get_tree(variable_get('forum_nav_vocabulary', ''), $tid);
    $n = 0;
    foreach ($_forums as $forum) {
      if (in_array($forum->tid, variable_get('forum_containers', array()))) {
        $forum->container = 1;
      }
      $forum->num_topics = _forum_num_topics($forum->tid);
      $forum->num_posts = _forum_num_replies($forum->tid) + $forum->num_topics;
      $forum->last_post = _forum_last_post($forum->tid);
      $forums[$forum->tid] = $forum;
      $n++;
    }

    cache_set("forum:$tid", serialize($forums), 1);
  }
  else {
    $forums = unserialize($cache->data);
  }

  return $forums;
}

function _forum_num_topics($term) {
  return db_result(db_query('SELECT COUNT(*) FROM {forum} f INNER JOIN {node} n ON n.nid = f.nid WHERE f.tid = %d AND n.status = 1 AND f.shadow = 0', $term));
}

function _forum_num_replies($term) {
  return db_result(db_query("SELECT COUNT(*) AS count FROM {comments} c INNER JOIN {node} n ON n.nid = c.nid INNER JOIN {forum} f ON n.nid = f.nid WHERE f.tid = %d AND n.nid = f.nid AND n.nid = c.nid AND n.status = 1 AND c.status = 0 AND n.type = 'forum'", $term));
}

function _forum_topics_read($term, $uid) {
  // Calculate the number of topics the user has read. Assume all entries older
  // than NODE_NEW_LIMIT are read, and include the recent posts that user has
  // read.
  $ancient = db_result(db_query('SELECT COUNT(*) FROM {forum} f INNER JOIN {node} n ON f.nid = n.nid WHERE f.tid = %d AND n.status = 1 AND n.created <= %d AND f.shadow = 0', $term, NODE_NEW_LIMIT));
  $recent = db_result(db_query('SELECT COUNT(*) FROM {forum} f INNER JOIN {node} n ON f.nid = n.nid INNER JOIN {history} h ON n.nid = h.nid WHERE n.status = 1 AND f.tid = %d AND h.uid = %d AND n.created > %d AND f.shadow = 0', $term, $uid, NODE_NEW_LIMIT));

  return $ancient + $recent;
}

function _forum_last_post($term) {
  $topic = db_fetch_object(db_query_range("SELECT n.nid, n.created AS timestamp, u.name AS name, u.uid AS uid FROM {forum} f INNER JOIN {node} n ON n.nid = f.nid INNER JOIN {users} u ON n.uid = u.uid WHERE f.tid = %d AND n.nid = f.nid AND n.type = 'forum' AND n.status = 1 ORDER BY timestamp DESC", $term, 0, 1));

  $reply = db_fetch_object(db_query_range("SELECT n.nid, c.timestamp, u.name AS name, u.uid AS uid FROM {forum} f INNER JOIN {node} n ON n.nid = f.nid INNER JOIN {comments} c ON n.nid = c.nid INNER JOIN {users} u ON c.uid = u.uid WHERE f.tid = %d AND n.nid = f.nid AND n.type = 'forum' AND n.status = 1 AND c.status = 0 ORDER BY c.timestamp DESC", $term, 0, 1));

  $value = ($topic->timestamp > $reply->timestamp) ? $topic : $reply;

  return $value;
}

function forum_get_topics($tid, $sortby, $forum_per_page) {
  global $user, $forum_topic_list_header;

  $forum_topic_list_header = array(
    array('data' => '&nbsp;'),
    array('data' => t('Topic'), 'field' => 'n.title'),
    array('data' => t('Replies'), 'field' => 'num_comments'),
    array('data' => t('Created'), 'field' => 'n.created'),
    array('data' => t('Last reply'), 'field' => 'date_sort', 'sort' => 'desc'),
  );

  $sql_sortby = _forum_get_topic_order($sortby);
  for ($i = 0; $i < count($forum_topic_list_header); $i++) {
    if ($forum_topic_list_header[$i]['field'] == $sql_sortby) {
      $forum_topic_list_header[$i]['order'] = $sql_sortby;
    }
  }

  $term = taxonomy_get_term($tid);
  $voc = taxonomy_get_vocabulary($term->vid);
  $check_tid = $tid ? "'". check_query($tid) ."'" : 'NULL';

  // show topics with the correct tid, or in the forum but with shadow = 1
  // @TODO: this is not ANSI SQL! ("user error: 'n.created' isn't in GROUP BY")
  // @TODO: timestamp is a sql reserved word. are there more?
  $sql = "SELECT n.nid, n.title, u.name AS name, u.uid AS uid, n.created AS timestamp, GREATEST(n.created, MAX(c.timestamp)) AS date_sort, COUNT(c.nid) AS num_comments, n.comment AS comment_mode, f.tid FROM {node} n INNER JOIN {term_node} r ON n.nid = r.nid INNER JOIN {users} u ON n.uid = u.uid LEFT JOIN {comments} c ON n.nid = c.nid INNER JOIN {forum} f ON n.nid = f.nid WHERE n.nid = r.nid AND ((r.tid = $check_tid AND f.shadow = 1) OR f.tid = $check_tid) AND n.status = 1 AND n.type = 'forum' GROUP BY n.nid, n.title, u.name, u.uid, n.created, n.comment, f.tid";
  $sql .= tablesort_sql($forum_topic_list_header);

  $sql_count = "SELECT COUNT(DISTINCT(n.nid)) FROM {node} n INNER JOIN {forum} f ON n.nid = f.nid INNER JOIN {term_node} r ON n.nid = r.nid WHERE n.nid = r.nid AND ( (r.tid = $check_tid AND f.shadow = 1) OR f.tid = $check_tid) AND n.status = 1 AND n.type = 'forum'";

  $result = pager_query($sql, $forum_per_page, 0, $sql_count);
  $topic_num = db_num_rows($result);

  $n = 0;
  while ($topic = db_fetch_object($result)) {
    if ($user->uid) {
      $history = _forum_user_last_visit($topic->nid);
      // folder is new if topic is new or there are new comments since last visit
      if ($topic->shadow > 0) {
        $topic->new = 0;
      }
      else {
        $topic->new_replies = db_result(db_query('SELECT COUNT(c.nid) FROM {node} n INNER JOIN {comments} c ON n.nid = c.nid WHERE n.nid = %d AND n.status = 1 AND c.status = 0 AND c.timestamp > %d', $topic->nid, $history));
        $topic->new = $topic->new_replies || ($topic->timestamp > $history);
      }
    }
    else {
      // you're not logged in eh?
      $topic->new_replies = 0;
      $topic->new = 0;
    }

    $topic->last_reply = _forum_last_reply($topic->nid);
    $topics[] = $topic;
  }

  return $topics;
}

function _forum_new($tid) {
  global $user;
  $result = db_query("SELECT n.nid FROM {node} n, {history} h, {forum} f WHERE n.type = 'forum' AND n.status = 1 AND h.nid = n.nid AND f.nid = h.nid AND f.tid = %d AND h.uid = %d", $tid, $user->uid);
  while ($r = db_fetch_object($result)) {
    $read[] = $r->nid;
  }

  $nid = db_result(db_query_range("SELECT n.nid FROM {node} n INNER JOIN {forum} f ON n.nid = f.nid WHERE n.type = 'forum' AND f.nid = n.nid AND n.status = 1 AND f.tid = %d ". ($read ? "AND NOT (n.nid IN (". implode(',', $read) .")) " : '') ."ORDER BY created", $tid, 0, 1));

  return $nid ? $nid : 0;
}

function forum_page() {
  global $sortby, $forum_per_page, $from, $user;

  $op = $_POST['op'];

  if (module_exist('taxonomy')) {
    $tid = arg(1);

    if (arg(2) == 'new') {
      if ($nid = _forum_new($tid)) {
        drupal_goto("node/view/$nid");
      }
    }

    if (empty($sortby)) {
      $sortby = isset($user->sortby) ? $user->sortby : variable_get('forum_order', 1);
    }

    if (empty($forum_per_page)) {
      $forum_per_page = isset($user->forum_per_page) ? $user->forum_per_page : variable_get('forum_per_page', 25);
    }

    $offset = ($from / $forum_per_page) + 1;

    $forums = forum_get_forums($tid);
    $parents = taxonomy_get_parents_all($tid);
    if ($tid && !in_array($tid, variable_get('forum_containers', array()))) {
      $topics = forum_get_topics($tid, $sortby, $forum_per_page);
    }

    print theme('forum_display', $forums, $topics, $parents, $tid, $sortby, $forum_per_page, $offset);
  }
  else {
    print theme('page', forum_help('admin/system/modules/forum'), t('Warning'));
  }
}

/**
 * @addtogroup themeable
 * @{
 */

/**
 * Format the forum body.
 *
 * @param forums
 * @param topics
 * @param parents
 * @param tid
 * @param sortby
 * @param forum_per_page
 * @param offset
 *
 * @return the output for the forum body.
 */
function theme_forum_display($forums, $topics, $parents, $tid, $sortby, $forum_per_page, $offset) {
  // forum list, topics list, topic browser and 'add new topic' link

  $vocabulary = taxonomy_get_vocabulary(variable_get('forum_nav_vocabulary', ''));
  $title = $vocabulary->name;

  /*
  ** Breadcrumb navigation:
  */
  $breadcrumb[] = l(t('Home'), '');
  if ($tid) {
    $breadcrumb[] = l($title, 'forum');
  }

  if ($parents) {
    $parents = array_reverse($parents);
    foreach ($parents as $p) {
      if ($p->tid == $tid) {
        $title = $p->name;
      }
      else {
        $breadcrumb[] = l($p->name, "forum/$p->tid");
      }
    }
  }

  if (count($forums) || count($parents)) {
    $output  = "<div id=\"forum\">";
    $output .= theme('forum_list', $forums, $parents, $tid);

    if ($tid && !in_array($tid, variable_get('forum_containers', array()))) {
      $output .= theme('forum_topic_list', $tid, $topics, $sortby, $forum_per_page, $offset);
    }
    $output .= "</div>";
  }
  else {
    $title = t('No forums defined');
    $output = '';
  }

  print theme('page', $output, $title, $breadcrumb);
}

/**
 * Format the forum listing.
 *
 * @param forums
 * @param parents
 * @param tid
 *
 * @return output for the forum listing.
 */
function theme_forum_list($forums, $parents, $tid) {
  global $user;

  if ($forums) {

    $header = array(t('Forum'), t('Topics'), t('Posts'), t('Last post'));

    foreach ($forums as $forum) {
      if ($forum->container) {
        $description  = "<div style=\"margin-left: ". ($forum->depth * 30) ."px;\">\n";
        $description .= " <div class=\"name\">". l($forum->name, "forum/$forum->tid") ."</div>\n";

        if ($forum->description) {
          $description .= " <div class=\"description\">$forum->description</div>\n";
        }
        $description .= "</div>\n";

        $rows[] = array(array('data' => $description, 'class' => 'container', 'colspan' => 4));
      }
      else {
        $forum->old_topics = _forum_topics_read($forum->tid, $user->uid);
        if ($user->uid) {
          $new_topics = $forum->num_topics - $forum->old_topics;
        }
        else {
          $new_topics = 0;
        }

        $links = array();

        $description  = "<div style=\"margin-left: ". ($forum->depth * 30) ."px;\">\n";
        $description .= " <div class=\"name\">". l($forum->name, "forum/$forum->tid") ."</div>\n";

        if ($forum->description) {
          $description .= " <div class=\"description\">$forum->description</div>\n";
        }
        if ($links) {
          $description .= " <div class=\"links\">". t('Jump to: %links', array('%links' => implode(', ', $links))) .".</div>\n";
        }
        $description .= "</div>\n";

        $rows[] = array(
          array('data' => $description, 'class' => 'forum'),
          array('data' => $forum->num_topics . ($new_topics ? "<br />". l(t('%a new', array('%a' => $new_topics)), "forum/$forum->tid", NULL, NULL, 'new') : ''), 'class' => 'topics'),
          array('data' => $forum->num_posts, 'class' => 'posts'),
          array('data' => _forum_format($forum->last_post), 'class' => 'last-reply'));
      }
    }
  }

  return theme('table', $header, $rows);
}

/**
 * Format the topic listing.
 *
 * @param tid
 * @param topics
 * @param sortby
 * @param forum_per_page
 * @param offset
 *
 * @return output for the topic list.
 */
function theme_forum_topic_list($tid, $topics, $sortby, $forum_per_page, $offset) {
  global $user, $id, $status, $user, $pager_total, $forum_topic_list_header;

  if ($topics) {

    foreach ($topics as $topic) {
      // folder is new if topic is new or there are new comments since last visit
      if ($topic->tid != $tid) {
        $rows[] = array(
          array('data' => _forum_icon($topic->new, $topic->num_comments, $topic->comment_mode), 'class' => 'icon'),
          array('data' => $topic->title, 'class' => 'title'),
          array('data' => l(t('This topic has been moved'), "forum/$topic->tid"), 'colspan' => '3')
        );
      }
      else {
        $rows[] = array(
          array('data' => _forum_icon($topic->new, $topic->num_comments, $topic->comment_mode), 'class' => 'icon'),
          array('data' => l($topic->title, "node/view/$topic->nid"), 'class' => 'topic'),
          array('data' => $topic->num_comments . ($topic->new_replies ? "<br />". l(t('%a new', array('%a' => $topic->new_replies)), "node/view/$topic->nid", NULL, NULL, 'new') : ''), 'class' => 'replies'),
          array('data' => _forum_format($topic), 'class' => 'created'),
          array('data' => _forum_format($topic->last_reply), 'class' => 'last-reply')
        );
      }
    }

    if ($pager = theme('pager', NULL, $forum_per_page, 0, tablesort_pager())) {
      $rows[] = array(array('data' => $pager, 'colspan' => '5', 'class' => 'pager'));
    }
  }

  if (user_access('create forum topics')) {
    $output = '<p>'. t('You can <a href="%post">post</a> new forum topics.', array('%post' => url("node/add/forum/$tid"))) .'</p>';
  }
  else if ($user->uid) {
    $output = '<p>'. t('You are not allowed to post new forum topics.') .'</p>';
  }
  else {
    $output = '<p>'. t('You must <a href="%login">login</a> to post new forum topics.', array('%login' => url('user/login'))) .'</p>';
  }

  $output .= theme('table', $forum_topic_list_header, $rows);

  return $output;
}

/** @} End of addtogroup themeable */

function _forum_icon($new_posts, $num_posts = 0, $comment_mode = 0) {

  $base_path = variable_get('forum_icon_path', '');
  if ($base_path) {
    if ($num_posts > variable_get('forum_hot_topic', 15)) {
      $icon = $new_posts ? 'hot-new' : 'hot';
    }
    else {
      $icon = $new_posts ? 'new' : 'default';
    }

    if ($comment_mode == 1) {
      $icon = 'closed';
    }

    // default
    $file = $base_path ."/forum-$icon.gif";

    $output = "<img src=\"$file\" alt=\"\" title=\"\" />";
  }
  else {
    $output = '&nbsp;';
  }

  if ($new_posts) {
    $output = "<a name=\"new\">$output</a>";
  }

  return $output;
}

function _forum_user_last_visit($nid) {
  global $user;
  static $history = array();

  if (empty($history)) {
    $result = db_query('SELECT nid, timestamp FROM {history} WHERE uid = %d', $user->uid);
    while ($t = db_fetch_object($result)) {
      $history[$t->nid] = $t->timestamp > NODE_NEW_LIMIT ? $t->timestamp : NODE_NEW_LIMIT;
    }
  }
  return $history[$nid] ? $history[$nid] : NODE_NEW_LIMIT;
}

function _forum_get_topic_order($sortby) {
  switch ($sortby) {
    case 1:
      return 'date_sort DESC';
      break;
    case 2:
      return 'date_sort ASC';
      break;
    case 3:
      return 'num_comments DESC';
      break;
    case 4:
      return 'num_comments ASC';
      break;
  }
}

?>