forum.module.php

<?php

function forum_block($op = 'list', $delta = 0, $edit = array()) {
  switch ($op) {
    case 'list':
      $blocks[0]['info'] = t('Active forum topics');
      $blocks[1]['info'] = t('New forum topics');
      return $blocks;

    case 'configure':
      $form['forum_block_num_'. $delta] = array('#type' => 'select', '#title' => t('Number of topics'), '#default_value' => variable_get('forum_block_num_'. $delta, '5'), '#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;

    case 'save':
      variable_set('forum_block_num_'. $delta, $edit['forum_block_num_'. $delta]);
      break;

    case 'view':
      if (user_access('access content')) {
        $block = cache_get(__FUNCTION__.$delta);
        if ($block !== 0) {
          return $block->data;
        }
        
        switch ($delta) {
          case 0:
            $title = t('Active forum topics');
            $sql = db_rewrite_sql("SELECT n.nid, n.title, l.comment_count, l.last_comment_timestamp FROM {node} n INNER JOIN {term_node} tn ON tn.vid = n.vid INNER JOIN {term_data} td ON td.tid = tn.tid INNER JOIN {node_comment_statistics} l ON n.nid = l.nid WHERE n.status = 1 AND td.vid = %d ORDER BY l.last_comment_timestamp DESC");
            $result = db_query_range($sql, variable_get('forum_nav_vocabulary', ''), 0, variable_get('forum_block_num_0', '5'));
            $content = node_title_list($result);
            break;

          case 1:
            $title = t('New forum topics');
            $sql = db_rewrite_sql("SELECT n.nid, n.title, l.comment_count FROM {node} n INNER JOIN {term_node} tn ON tn.vid = n.vid INNER JOIN {term_data} td ON td.tid = tn.tid INNER JOIN {node_comment_statistics} l ON n.nid = l.nid WHERE n.status = 1 AND td.vid = %d ORDER BY n.nid DESC");
            $result = db_query_range($sql, variable_get('forum_nav_vocabulary', ''), 0, variable_get('forum_block_num_1', '5'));
            $content = node_title_list($result);
            break;
        }

        if (!empty($content)) {
          $block = array();
          $block['subject'] = $title;
          $block['content'] = $content . theme('more_link', url('forum'), t('Read the latest forum topics.'));
          cache_set(__FUNCTION__.$delta, $block, 'cache_block', time() + 300);
          return $block;
        }
      }
  }
}