Tag list block for Drupal 6.x

tag-list.php

<?php
  /**
   * Abstraction-breaking custom tag lister.
   * This block lists all tags under the given taxonomy vocabulary,
   * in order of frequency, and then name. The tags are hyperlinked.
   */
  $vocabulary_id = 8;
  $cutoff = 15;       // don't show results that don't pass the threshold
  $threshold = 5;     // after cutoff, don't show tags with counts less than this
  $tag_query = "SELECT td.tid, td.name, COUNT(DISTINCT tn.nid) as num " .
               "FROM term_data td, " .
               "     term_node tn " .
               "WHERE td.vid = %d AND " .
               "      td.tid = tn.tid " .
               "GROUP BY td.tid, td.name " .
               "ORDER BY num DESC, td.name ASC ";
  $result = db_query($tag_query, $vocabulary_id);

  if ($result) {

    print "<div class=\"item-list\">";
    print "<ul>";
    $results_so_far = 0;
    while ($row = db_fetch_object($result)) {
      $results_so_far++;
      if ($results_so_far > $cutoff && $row->num <= $threshold)
        break;
      print "<li>" .
            "<a href=\"/site/taxonomy/term/" . $row->tid . "\">" .
            $row->name .
            "</a>" .
            " (" . $row->num . ")" .
            "</li>";
    }
    print "</ul>";
    print "</div>";

  } else {

    print "Tags unavailable.";

  }
?>