taxonomy.module

<?php
// $Id$

function taxonomy_feed($taxonomy) {
  global $id, $type;

  if ($type == "voc") {
    //TODO - vocabulary feed.
  }
  else {
    $result = taxonomy_select_nodes($taxonomy, 0);
    $term = taxonomy_get_term($taxonomy->tids[0]);
    $channel["link"] = url("taxonomy/view/$taxonomy->operator/$taxonomy->str_tids", NULL, NULL, TRUE);
    $channel["title"] = variable_get("site_name", "drupal") ." - ". $term->name;
    $channel["description"] = $term->description;
    node_feed($result, $channel);
  }
}

function taxonomy_perm() {
  return array("administer taxonomy");
}

/**
 * Implementation of hook_link().
 *
 * This hook is extended with $type = 'taxonomy terms' to allow themes to
 * print lists of terms associated with a node. Themes can print taxonomy
 * links with:
 *
 * if (module_exist('taxonomy')) {
 *   $this->links(taxonomy_link('taxonomy terms', $node));
 * }
 */
function taxonomy_link($type, $node = NULL) {
  if ($type == 'system') {
      menu('admin/taxonomy', t('categories'), user_access('administer taxonomy') ? 'taxonomy_admin' : MENU_DENIED, 3);
      menu('admin/taxonomy/add/vocabulary', t('create new vocabulary'), user_access('administer taxonomy') ? 'taxonomy_admin' : MENU_DENIED);
      menu('admin/taxonomy/help', t('help'), user_access('administer taxonomy') ? 'taxonomy_admin' : MENU_DENIED, 9);

      menu('taxonomy', t('taxonomy'), user_access('access content') ? 'taxonomy_page' : MENU_DENIED, 0, MENU_HIDE, MENU_LOCKED);
  }
  else if ($type == 'taxonomy terms' && $node != NULL) {
    $links = array();
    if ($node->taxonomy) {
      foreach ($node->taxonomy as $tid) {
        $term = taxonomy_get_term($tid);
        $links[] = l($term->name, "taxonomy/page/or/$term->tid", $term->description ? array ('title' => $term->description) : array());
      }
    }
    else {
      $links = array();
      foreach (taxonomy_node_get_terms($node->nid) as $term) {
        $links[] = l($term->name, "taxonomy/page/or/$term->tid", $term->description ? array ('title' => $term->description) : array());
      }

    }
    return $links;
  }
}

/*
** admin pages (form, save, overview)
*/

function taxonomy_form_vocabulary($edit = array()) {
  foreach (node_list() as $type) {
    $nodetypes[$type] = node_invoke($type, "node_name");
  }

  $form .= form_textfield(t("Vocabulary name"), "name", $edit["name"], 50, 64, t("Required") .". ". t("The name for this vocabulary.  Example: 'Topic'") .".");
  $form .= form_textarea(t("Description"), "description", $edit["description"], 60, 5, t("Optional") .". ". t("Description of the vocabulary, can be used by modules."));
  $form .= form_textfield(t("Help text"), "help", $edit["help"], 50, 255, t("Optional") .". ". t("Instructions to present to the user when choosing a term.") .".");
  $form .= form_checkboxes(t("Types"), "nodes", explode(",", $edit["nodes"]), $nodetypes, t("Required") .". ". t("A list of node types you want to associate this vocabulary with."));
  $form .= form_checkbox(t("Related terms"), "relations", 1, $edit["relations"], t("Optional") .". ". t("Allows <a href=\"%help-url\">related terms</a> in this vocabulary.", array("%help-url" => url("admin/taxonomy/help", NULL, NULL, "related-terms"))));
  $form .= form_radios(t("Hierarchy"), "hierarchy", $edit["hierarchy"], array(t("Disabled"), t("Single"), t("Multiple")), t("Optional") .". ". t("Allows <a href=\"%help-url\">a tree-like hierarchy</a> between terms of this vocabulary.", array("%help-url" => url("admin/taxonomy/help", NULL, NULL, "hierarchy"))), "", 0);
  $form .= form_checkbox(t("Multiple select"), "multiple", 1, $edit["multiple"], t("Optional") .". ". t("Allows nodes to have more than one term in this vocabulary."));
  $form .= form_checkbox(t("Required"), "required", 1, $edit["required"], t("If enabled every node <strong>must</strong> have at least one term in this vocabulary"));
  $form .= form_weight(t("Weight"), "weight", $edit["weight"], 10, t("Optional. In listings, the heavier vocabularies will sink and the lighter vocabularies will be positioned nearer the top."));
  $form .= form_submit(t("Submit"));

  if ($edit["vid"]) {
    $form .= form_submit(t("Delete"));
    $form .= form_hidden("vid", $edit["vid"]);
  }

  return form($form);
}

function taxonomy_save_vocabulary($edit) {
  if (!$edit["nodes"]) {
    $edit["nodes"] = array();
  }

  $data = array("name" => $edit["name"], "nodes" => implode(",", $edit["nodes"]), "description" => $edit["description"], "help" => $edit["help"], "multiple" => $edit["multiple"], "required" => $edit["required"], "hierarchy" => $edit["hierarchy"], "relations" => $edit["relations"], "weight" => $edit["weight"]);
  if ($edit["vid"] && $edit["name"]) {
    db_query("UPDATE {vocabulary} SET ". _prepare_update($data) ." WHERE vid = %d", $edit["vid"]);
    module_invoke_all("taxonomy", "update", "vocabulary", $edit);
    $message = t("updated vocabulary '%name'.", array("%name" => $edit["name"]));
  }
  else if ($edit["vid"]) {
    $message = taxonomy_del_vocabulary($edit["vid"]);
  }
  else {
    $data["vid"] = $edit["vid"] = db_next_id("{vocabulary}_vid");
    db_query("INSERT INTO {vocabulary} ". _prepare_insert($data, 1) ." VALUES ". _prepare_insert($data, 2));
    module_invoke_all("taxonomy", "insert", "vocabulary", $edit);
    $message = t("created new vocabulary '%name'.", array("%name" => $edit["name"]));
  }

  cache_clear_all();

  drupal_set_message($message);
  return $edit;
}

function taxonomy_del_vocabulary($vid) {
  $vocabulary = taxonomy_get_vocabulary($vid);

  db_query("DELETE FROM {vocabulary} WHERE vid = %d", $vid);
  $result = db_query("SELECT tid FROM {term_data} WHERE vid = %d", $vid);
  while ($term = db_fetch_object($result)) {
    taxonomy_del_term($term->tid);
  }

  module_invoke_all("taxonomy", "delete", "vocabulary", $vocabulary);

  cache_clear_all();

  return t("deleted vocabulary '%name'.", array("%name" => $vocabulary->name));
}

function _taxonomy_confirm_del_vocabulary($vid) {
  $vocabulary = taxonomy_get_vocabulary($vid);

  $form .= form_hidden("confirm", 1);
  $form .= form_hidden("type", "vocabulary");
  $form .= form_hidden("vid", $vid);
  $form .= form_submit(t("Delete"));
  $form .= form_submit(t("Cancel"));

  return form(form_item(t("Delete vocabulary '%name'", array("%name" => $vocabulary->name)), $form, t("Are you sure you want to delete the vocabulary and all its terms?")));
}

function taxonomy_form_term($edit = array()) {
  $vocabulary_id = isset($edit["vid"]) ? $edit["vid"] : arg(4);
  $vocabulary = taxonomy_get_vocabulary($vocabulary_id);

  $form = form_textfield(t("Term name"), "name", $edit["name"], 50, 64, t("Required") .". ". t("The name for this term.  Example: 'Linux'."));
  $form .= form_textarea(t("Description"), "description", $edit["description"], 60, 5, t("Optional") .". ". t("A description of the term."));

  if ($vocabulary->hierarchy) {
    $parent = array_keys(taxonomy_get_parents($edit["tid"]));
    $children = taxonomy_get_tree($vocabulary_id, $edit["tid"]);

    // you can't be son of yourself nor of your children
    foreach ($children as $child) {
      $exclude[] = $child->tid;
    }
    $exclude[] = $edit["tid"];

    if ($vocabulary->hierarchy == 1) {
      $form .= _taxonomy_term_select(t("Parent"), "parent", $parent, $vocabulary_id, t("Required") .". ". l(t("Parent term"), "admin/taxonomy/help", NULL, NULL, "parent") .".", 0, "<". t("root") .">", $exclude);
    }
    elseif ($vocabulary->hierarchy == 2) {
      $form .= _taxonomy_term_select(t("Parents"), "parent", $parent, $vocabulary_id, t("Required") .". ". l(t("Parent terms"), "admin/taxonomy/help", NULL, NULL, "parent") .".", 1, "<". t("root") .">", $exclude);
    }
  }

  if ($vocabulary->relations) {
    $form .= _taxonomy_term_select(t("Related terms"), "relations", array_keys(taxonomy_get_related($edit["tid"])), $vocabulary_id, t("Optional") .". ", 1, "<". t("none") .">", array($edit["tid"]));
  }

  $form .= form_textarea(t("Synonyms"), "synonyms", implode("\n", taxonomy_get_synonyms($edit["tid"])), 30, 5, t("Optional") . ". ". t("<a href=\"%help-url\">Synonyms</a> of this term, one synonym per line.", array("%help-url" => url("admin/taxonomy/help", NULL, NULL, "synonyms"))));
  $form .= form_weight(t("Weight"), "weight", $edit["weight"], 10, t("Optional. In listings, the heavier terms will sink and the lighter terms will be positioned nearer the top."));
  $form .= form_hidden("vid", $vocabulary->vid);
  $form .= form_submit(t("Submit"));

  if ($edit["tid"]) {
    $form .= form_submit(t("Delete"));
    $form .= form_hidden("tid", $edit["tid"]);
  }

  return form($form);
}

function taxonomy_save_term($edit) {
  if ($edit["tid"] && $edit["name"]) {
    $data = array("name" => $edit["name"], "description" => $edit["description"], "weight" => $edit["weight"]);

    db_query("UPDATE {term_data} SET ". _prepare_update($data) ." WHERE tid = %d", $edit["tid"]);
    module_invoke_all("taxonomy", "update", "term", $edit);
    $message = t("the term '%a' has been updated.", array("%a" => $edit["name"]));
  }
  else if ($edit["tid"]) {
    return taxonomy_del_term($edit["tid"]);
  }
  else {
    $edit["tid"] = db_next_id("{term_data}_tid");
    $data = array("tid" => $edit["tid"], "name" => $edit["name"], "description" => $edit["description"], "vid" => $edit["vid"], "weight" => $edit["weight"]);
    db_query("INSERT INTO {term_data} ". _prepare_insert($data, 1) ." VALUES ". _prepare_insert($data, 2));
    module_invoke_all("taxonomy", "insert", "term", $edit);
    $message = t("created new term '%name'.", array("%name" => $edit["name"]));
  }

  // relations (seem very powerful, but I have to understand it completely)
  db_query("DELETE FROM {term_relation} WHERE tid1 = %d OR tid2 = %d", $edit["tid"], $edit["tid"]);
  if ($edit["relations"]) {
    foreach ($edit["relations"] as $related_id) {
      if ($related_id != 0) {
        db_query("INSERT INTO {term_relation} (tid1, tid2) VALUES (%d, %d)", $edit["tid"], $related_id);
      }
    }
  }

  // hierarchy
  db_query("DELETE FROM {term_hierarchy} WHERE tid = %d", $edit["tid"]);
  if (!isset($edit["parent"])) {
    $edit["parent"] = 0;
  }
  if (is_array($edit["parent"])) {
    foreach ($edit["parent"] as $parent) {
      db_query("INSERT INTO {term_hierarchy} (tid, parent) VALUES (%d, %d)", $edit["tid"], $parent);
    }
  }
  else {
    db_query("INSERT INTO {term_hierarchy} (tid, parent) VALUES (%d, %d)", $edit["tid"], $edit["parent"][0]);
  }

  db_query("DELETE FROM {term_synonym} WHERE tid = %d", $edit["tid"]);
  if ($edit["synonyms"]) {
    foreach (explode ("\n", str_replace("\r", "", $edit["synonyms"])) as $synonym) {
      if ($synonym) {
        db_query("INSERT INTO {term_synonym} (tid, name) VALUES (%d, '%s')", $edit["tid"], chop($synonym));
      }
    }
  }

  cache_clear_all();

  drupal_set_message($message);
  return $edit;
}

function taxonomy_del_term($tid) {
  $term = taxonomy_get_term($tid);

  db_query("DELETE FROM {term_data} WHERE tid = %d", $tid);
  db_query("DELETE FROM {term_hierarchy} WHERE tid = %d", $tid);
  db_query("DELETE FROM {term_relation} WHERE tid1 = %d OR tid2 = %d", $tid, $tid);
  db_query("DELETE FROM {term_synonym} WHERE tid = %d", $tid);
  db_query("DELETE FROM {term_node} WHERE tid = %d", $tid);

  module_invoke_all("taxonomy", "delete", "term", $term);

  cache_clear_all();

  return t("deleted term '%name'.", array("%name" => $term->name));
}

function _taxonomy_confirm_del_term($tid) {
  $term = taxonomy_get_term($tid);

  $form .= form_hidden("confirm", 1);
  $form .= form_hidden("type", "term");
  $form .= form_hidden("tid", $tid);
  $form .= form_submit(t("Delete"));
  $form .= form_submit(t("Cancel"));

  return form(form_item(t("Delete term '%name'", array("%name" => $term->name)), $form, t("Are you sure you want to delete the term?")));
}

function taxonomy_overview() {

  $output .= "<h3>". t("Vocabularies overview") ."</h3>";

  $header = array(t("name"), t("node types"), array("data" => t("operations"), "colspan" => 3));

  $vocabularies = taxonomy_get_vocabularies();

  foreach ($vocabularies as $vocabulary) {
    $links = array();
    $types = array();
    foreach(explode(",", $vocabulary->nodes) as $type) {
      $types[] = node_invoke($type, "node_name");
    }
    $rows[] = array($vocabulary->name, array("data" => implode(", ", $types), "align" => "center"), l(t("edit vocabulary"), "admin/taxonomy/edit/vocabulary/$vocabulary->vid"), l(t("add term"), "admin/taxonomy/add/term/$vocabulary->vid"), l(t("preview form"), "admin/taxonomy/preview/vocabulary/$vocabulary->vid"));

    $tree = taxonomy_get_tree($vocabulary->vid);
    if ($tree) {
      unset($data);
      foreach ($tree as $term) {
        $data .= _taxonomy_depth($term->depth) ." ". $term->name ." (". l(t("edit term"), "admin/taxonomy/edit/term/$term->tid") .")<br />";
      }
      $rows[] = array(array("data" => $data, "colspan" => 5));
    }
  }

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

function taxonomy_form($vocabulary_id, $value = 0, $error = array(), $help = NULL) {
  $vocabulary = taxonomy_get_vocabulary($vocabulary_id);
  $help = ($help) ? $help : $vocabulary->help;
  if ($vocabulary->required) {
    $blank = 0;
  }
  else {
    $blank = "<". t("none") .">";
  }

  $help .= $error['taxonomy'];

  return _taxonomy_term_select($vocabulary->name, 'taxonomy', $value, $vocabulary_id, $help, intval($vocabulary->multiple), $blank);
}

/*
** API functions
*/

// return array of vocabularies, as objects
function taxonomy_get_vocabularies($type = '', $key = "vid") {
  if ($type) {
    $result = db_query("SELECT * FROM {vocabulary} WHERE nodes LIKE '%%%s%%' ORDER BY weight, name", $type);
  }
  else {
    $result = db_query("SELECT * FROM {vocabulary} ORDER BY weight, name");
  }
  $vocabularies = array();
  while ($voc = db_fetch_object($result)) {
    $vocabularies[$voc->$key] = $voc;
  }

  return $vocabularies;
}

// return form with current term
function taxonomy_node_form($type, $node = '', $error = array()) {
  if (!$node->taxonomy) {
    if ($node->nid) {
      $terms = array_keys(taxonomy_node_get_terms($node->nid));
    }
    else {
      $terms = 0;
    }
  }
  else {
    $terms = $node->taxonomy;
  }

  $c = db_query("SELECT * FROM {vocabulary} WHERE nodes LIKE '%%%s%%' ORDER BY weight, name", $type);
  while ($vocabulary = db_fetch_object($c)) {
    $result[] .= taxonomy_form($vocabulary->vid, $terms, $error);
  }
  return $result ? $result : array();
}

// return 1 if node identified by $nid contains a taxonomy term identified by $tid in his body or title
function taxonomy_node_has_term($nid, $tid) {
  $term_name = db_result(db_query("SELECT name FROM {term_data} WHERE tid = %d", $tid));

  return db_result(db_query("SELECT COUNT(n.nid) FROM {node} n WHERE n.nid = %d AND ((n.body LIKE '%%%s%%') OR (n.body LIKE '%%%s%%'))", $nid, $term_name, $term_name));
}

// return array of terms of a node beloging to a particular vocabulary identified by $vid
function taxonomy_node_get_terms_by_vocabulary($nid, $vid, $key = "tid") {
  $result = db_query("SELECT t.* FROM {term_data} t, {term_node} r WHERE t.tid = r.tid AND t.vid = %d AND r.nid = %d ORDER BY weight", $vid, $nid);
  $terms = array();
  while ($term = db_fetch_object($result)) {
    $terms[$term->$key] = $term;
  }
  return $terms;
}

// return array of terms of a node
function taxonomy_node_get_terms($nid, $key = "tid") {
  static $terms;

  if (!isset($terms[$nid])) {
    $result = db_query("SELECT t.* FROM {term_data} t, {term_node} r WHERE r.tid = t.tid AND r.nid = %d ORDER BY weight, name", $nid);
    $terms[$nid] = array();
    while ($term = db_fetch_object($result)) {
      $terms[$nid][$term->$key] = $term;
    }
  }
  return $terms[$nid];
}

// save terms of a node
function taxonomy_node_save($nid, $terms) {
  taxonomy_node_delete($nid);

  if ($terms) {
    foreach ($terms as $term) {
      db_query("INSERT INTO {term_node} (nid, tid) VALUES (%d, %d)", $nid, $term);
    }
  }
}

// clean up terms
function taxonomy_node_delete($nid) {
  db_query("DELETE FROM {term_node} WHERE nid = %d", $nid);
}

// relations: return array of related terms
function taxonomy_get_related($tid, $key = "tid") {
  if ($tid) {
    $result = db_query("SELECT t.*, tid1, tid2 FROM {term_relation} , {term_data} t WHERE (t.tid = tid1 OR t.tid = tid2) AND (tid1 = %d OR tid2 = %d) AND t.tid != %d ORDER BY weight, name", $tid, $tid, $tid);
    $related = array();
    while ($term = db_fetch_object($result)) {
      $related[$term->$key] = $term;
    }
    return $related;
  }
  else {
    return array();
  }
}

// hierarchy: get parent terms
function taxonomy_get_parents($tid, $key = "tid") {
  if ($tid) {
    $result = db_query("SELECT t.* FROM {term_hierarchy} h, {term_data} t WHERE h.parent = t.tid AND h.tid = %d ORDER BY weight, name", $tid);
    $parents = array();
    while ($parent = db_fetch_object($result)) {
      $parents[$parent->$key] = $parent;
    }
    return $parents;
  }
  else {
    return array();
  }
}

// Gets all parents, parents of parents, etc.
function taxonomy_get_parents_all($tid, $key = "tid") {
  $parents = array();
  if ($tid) {
    $parents[] = taxonomy_get_term($tid);
    $n = 0;
    while ($parent = taxonomy_get_parents($parents[$n]->tid)) {
      $parents = array_merge($parents, $parent);
      $n++;
    }
  }
  return $parents;
}

// hierarchy: get children
function taxonomy_get_children($tid, $vid = 0, $key = "tid") {
  if ($vid) {
    $result = db_query("SELECT t.* FROM {term_hierarchy} h, {term_data} t WHERE t.vid = %d AND h.tid = t.tid AND h.parent = %d ORDER BY weight, name", $vid, $tid);
  }
  else {
    $result = db_query("SELECT t.* FROM {term_hierarchy} h, {term_data} t WHERE h.tid = t.tid AND parent = %d ORDER BY weight", $tid);
  }
  $children = array();
  while ($term = db_fetch_object($result)) {
    $children[$term->$key] = $term;
  }
  return $children;
}

// hierarchy: get whole family, with tid, parent and depth; useful to show
function taxonomy_get_tree($vocabulary_id, $parent = 0, $depth = -1, $key = "tid") {
  static $children, $parents, $terms;

  $depth++;

  // we cache trees, so it's not cpu-intensive to call get_tree on a term and its children too
  if (!isset($children[$vocabulary_id])) {
    $children[$vocabulary_id] = array();

    $result = db_query("SELECT t.*, parent FROM {term_data} t, {term_hierarchy} h WHERE t.tid = h.tid AND t.vid = %d ORDER BY weight, name", $vocabulary_id);
    while ($term = db_fetch_object($result)) {
      $children[$vocabulary_id][$term->parent][] = $term->tid;
      $parents[$vocabulary_id][$term->tid][] = $term->parent;
      $terms[$vocabulary_id][$term->tid] = $term;
    }
  }

  if ($children[$vocabulary_id][$parent]) {
    foreach ($children[$vocabulary_id][$parent] as $child) {
      $terms[$vocabulary_id][$child]->depth = $depth;
      unset($terms[$vocabulary_id][$child]->parent); // this is not useful as it would show one parent only
      $terms[$vocabulary_id][$child]->parents = $parents[$vocabulary_id][$child];
      $tree[] = $terms[$vocabulary_id][$child];

      $tree = array_merge($tree, taxonomy_get_tree($vocabulary_id, $child, $depth));
    }
  }

  return $tree ? $tree : array();
}

// synonyms: return array of synonyms
function taxonomy_get_synonyms($tid) {
  if ($tid) {
    $result = db_query("SELECT name FROM {term_synonym} WHERE tid = %d", $tid);
    while ($synonym = db_fetch_array($result)) {
      $synonyms[] = $synonym["name"];
    }
    return $synonyms ? $synonyms : array();
  }
  else {
    return array();
  }
}

// synonyms: return original term
function taxonomy_get_synonym_root($term) {
  return db_fetch_object(db_query("SELECT * FROM {term_synonym} s, {term_data} t WHERE t.tid = s.tid AND s.name = '%s'", $term));
}

// given a term id, count number of published nodes in it
function taxonomy_term_count_nodes($tid, $type = 0) {
  static $count;

  if (!isset($count[$type])) {
    // $type == 0 always evaluates true is $type is a string
    if (is_numeric($type)) {
      $result = db_query("SELECT t.tid, COUNT(*) AS c FROM {term_node} t INNER JOIN {node} n ON t.nid = n.nid WHERE n.status = 1 GROUP BY t.tid");
    }
    else {
      $result = db_query("SELECT t.tid, COUNT(*) AS c FROM {term_node} t, {node} n WHERE t.nid = n.nid AND n.status = 1 AND n.type = '%s' GROUP BY t.tid", $type);
    }
    while ($term = db_fetch_object($result)) {
      $count[$type][$term->tid] = $term->c;
    }
  }

  foreach (_taxonomy_term_children($tid) as $c) {
    $children_count += taxonomy_term_count_nodes($c, $type);
  }
  return $count[$type][$tid] + $children_count;
}

// helper for above function
function _taxonomy_term_children($tid) {
  static $children;

  if (!isset($children)) {
    $result = db_query("SELECT tid, parent FROM {term_hierarchy} ");
    while ($term = db_fetch_object($result)) {
      $children[$term->parent][] = $term->tid;
    }
  }
  return $children[$tid] ? $children[$tid] : array();
}

/**
 * Try to map a string to existing vocabularies. Provide case insensitive and
 * trimmed map so as to maximize likelihood of successful mapping.
 *
 * @param $name Name of the vocabulary to search
 * @return array of matching vocabularies, as objects
 */
function taxonomy_get_vocabulary_by_name($name) {
  // LOWER is ANSI SQL-92
  $db_result = db_query("SELECT * FROM {vocabulary} WHERE LOWER('%s') LIKE LOWER(name)", trim($name));
  $result = array();
  while ($vocabulary = db_fetch_object($db_result)) {
    $result[] = $vocabulary;
  }

  return $result;
}

/**
 * Try to map a string to existing terms Provide case insensitive and trimmed
 * map so as to maximize likelihood of successful mapping.
 *
 * @param name Name of the term to search
 * @return rray of matching terms, as objects
 */
function taxonomy_get_term_by_name($name) {
  // LOWER is ANSI SQL-92
  $db_result = db_query("SELECT * FROM {term_data} WHERE LOWER('%s') LIKE LOWER(name)", trim($name));
  $result = array();
  while ($term = db_fetch_object($db_result)) {
    $result[] = $term;
  }

  return $result;
}

function taxonomy_get_vocabulary($vid) {
  // simple cache using a static var?
  return db_fetch_object(db_query("SELECT * FROM {vocabulary} WHERE vid = %d", $vid));
}

function taxonomy_get_term($tid) {
  // simple cache using a static var?
  return db_fetch_object(db_query("SELECT * FROM {term_data} WHERE tid = %d", $tid));
}

/*
** service functions
*/

function _taxonomy_term_select($title, $name, $value, $vocabulary_id, $description, $multiple, $blank, $exclude = array()) {
  $tree = taxonomy_get_tree($vocabulary_id);

  // We store the last selected ID in a session variable:
  if (!$value) {
    $value = $_SESSION['vocabulary']["$vocabulary_id"];
  }
  else {
    $_SESSION['vocabulary']["$vocabulary_id"] = $value;
  }

  if ($blank) {
    $options[] = array("tid" => 0, "name" => $blank);
  }

  if ($tree) {
    foreach ($tree as $term) {
      if (!in_array($term->tid, $exclude)) {
        $options[] = array("tid" => $term->tid, "name" => _taxonomy_depth($term->depth, '-').$term->name);
      }
    }
    if (!$blank && !$value) {
      // required but without a predefined value, so set first as predefined
      $value = $tree[0]->tid;
    }
  }

  if (count($options) > 0) {
    foreach ($options as $option) {
      $select .= "<option value=\"". $option["tid"] ."\"". (is_array($value) ? (in_array($option["tid"], $value) ? " selected=\"selected\"" : "") : ($option["tid"] == $value ? " selected=\"selected\"" : "")) .">". check_form($option["name"]) ."</option>";
    }

    $size = min(12, count($options));

    return form_item($title, "<select name=\"edit[$name][]\"". ($multiple ? " multiple=\"multiple\" size=\"$size\"" : "") . ($extra ? " $extra" : "") .">$select</select>", $description);
  }
}

function _taxonomy_depth($depth, $graphic = '--') {
  for ($n = 0; $n < $depth; $n++) {
    $result .= $graphic;
  }
  return $result;
}

function _prepare_update($data) {
  foreach ($data as $key => $value) {
    $q[] = "$key = '". check_query($value) ."'";
  }
  $result = implode(", ", $q);
  return $result;
}

function _prepare_insert($data, $stage) {
  if ($stage == 1) {
    $result = implode(", ", array_keys($data));
  }
  else {
    foreach (array_values($data) as $value) {
      $q[] = "'". check_query($value) ."'";
    }
    $result = implode(", ", $q);
  }
  return "($result)";
}

/*
** Accepts taxonomy conditions and returns a resource identifier.  If
** you intend to use the nodes without a pager (eg. in a XML feed),
** then set $pager to false.
*/
function taxonomy_select_nodes($taxonomy, $pager = 1) {
  global $user;

  if ($taxonomy->str_tids) {
    if ($taxonomy->operator == "or") {
      $sql = "SELECT DISTINCT(n.nid), n.title, n.type, n.created, n.changed, n.uid, n.static, n.created, u.name FROM {node} n INNER JOIN {term_node} r ON n.nid = r.nid INNER JOIN {users} u ON n.uid = u.uid WHERE r.tid IN ($taxonomy->str_tids) AND n.status = '1' ORDER BY static DESC, created DESC";
      $sql_count = "SELECT COUNT(DISTINCT(n.nid)) FROM {node} n INNER JOIN {term_node} r ON n.nid = r.nid INNER JOIN {users} u ON n.uid = u.uid WHERE r.tid IN ($taxonomy->str_tids) AND n.status = '1'";
    }
    else {
      $sql = "SELECT n.nid, n.title, n.type, n.created, n.changed, n.uid, u.name FROM {node} n INNER JOIN {term_node} r ON n.nid = r.nid INNER JOIN {users} u ON n.uid = u.uid WHERE r.tid IN ($taxonomy->str_tids) AND n.status = '1' GROUP BY n.nid, n.title, n.type, n.created, n.changed, n.uid, u.name HAVING COUNT(n.nid) = ". count($taxonomy->tids) ." ORDER BY static DESC, created DESC";

      // Special trick as we could not find anything better:
      $count = db_num_rows(db_query("SELECT n.nid FROM {node} n INNER JOIN {term_node} r ON n.nid = r.nid WHERE r.tid IN ($taxonomy->str_tids) AND n.status = '1' GROUP BY n.nid HAVING COUNT(n.nid) = ". count($taxonomy->tids)));
      $sql_count = "SELECT $count";
    }

    if ($pager) {
      $result = pager_query($sql, variable_get("default_nodes_main", 10) , 0, $sql_count);
    }
    else {
      $result = db_query_range($sql, 0, 15);
    }
  }

  return $result;
}

/*
** Accepts the result of a db_query() and formats each node along
** with a pager.
*/
function taxonomy_render_nodes($result) {

  while ($node = db_fetch_object($result)) {
    $output .= node_view(node_load(array("nid" => $node->nid, "type" => $node->type)), 1);
  }
  $output .= theme("pager", NULL, variable_get("default_nodes_main", 10), 0);
  return $output;
}

function taxonomy_nodeapi($node, $op, $arg = 0) {

  switch ($op) {
    case "insert":
      taxonomy_node_save($node->nid, $node->taxonomy);
      break;
    case "update":
      taxonomy_node_save($node->nid, $node->taxonomy);
      break;
    case "delete":
      taxonomy_node_delete($node->nid);
      break;
  }
}

function taxonomy_page() {

  $taxonomy->operator = arg(2);
  $taxonomy->str_tids = check_query(arg(3));
  $taxonomy->tids = explode(",", $taxonomy->str_tids);

  if (ereg("^([0-9]+,){0,}[0-9]+$", $taxonomy->str_tids)) {
    switch (arg(1)) {
      case "feed":
        taxonomy_feed($taxonomy);
      break;
      default:
      // Build title:
      $sql = 'SELECT name FROM {term_data} WHERE tid IN (%s)';
      $result = db_query($sql, $taxonomy->str_tids);
      $names = array();
      while ($term = db_fetch_object($result)) {
        $names[] = $term->name;
      }

      // Build breadcrumb based on first hierarchy of first term:
      $current->tid = $taxonomy->tids[0];
      while ($parents = taxonomy_get_parents($current->tid)) {
        $current = array_shift($parents);
        $breadcrumbs[] = l($current->name, "taxonomy/view/or/$current->tid");
      }
      $breadcrumbs[] = l(t('Home'), '');
      $breadcrumbs = array_reverse($breadcrumbs);

      drupal_set_html_head('<link rel="alternate" type="application/rss+xml" title="RSS - '. implode(' : ', $names) .'" href="'. url("taxonomy/feed/or/$taxonomy->str_tids") .'" />');

      $output = taxonomy_render_nodes(taxonomy_select_nodes($taxonomy));
      print theme("page", $output, implode(', ', $names), $breadcrumbs);
      break;
    }
  }
  else {
    drupal_not_found();
  }
}

/*
** admin
*/

function taxonomy_admin() {
  $op = $_POST["op"];
  $edit = $_POST["edit"];

  if (empty($op)) {
    $op = arg(2);
  }

  switch ($op) {
    case "add":
      if (arg(3) == "vocabulary") {
        $output .= taxonomy_form_vocabulary();
      }
      else if (arg(3) == "term") {
        $output .= taxonomy_form_term();
      }
      break;
    case "edit":
      if (arg(3) == "vocabulary") {
        $output .= taxonomy_form_vocabulary(object2array(taxonomy_get_vocabulary(arg(4))));
      }
      else if (arg(3) == "term") {
        $output .= taxonomy_form_term(object2array(taxonomy_get_term(arg(4))));
      }
      break;
    case "preview":
      $output .= taxonomy_form(arg(4));
      break;
    case "help":
      $output .= taxonomy_help();
      break;
    case t("Delete"):
      if (!$edit["confirm"]) {
        if (arg(3) == "vocabulary") {
          $output .= _taxonomy_confirm_del_vocabulary($edit["vid"]);
        }
        else {
          $output .= _taxonomy_confirm_del_term($edit["tid"]);
        }
        break;
      }
      else {
        $edit["name"] = 0;
        // fall through:
      }
    case t("Submit"):
      if (arg(3) == "vocabulary") {
        taxonomy_save_vocabulary($edit);
      }
      else {
        taxonomy_save_term($edit);
        if (!$edit["tid"]) {
          // if INSERT show form again
          $output .= taxonomy_form_term();
          break;
        }
        // else (UPDATE or DELETE) fall through
      }
      // fall through:
    default:
      $output .= taxonomy_overview();
  }

  print theme("page", $output);
}

function taxonomy_help($section = "admin/help#taxonomy") {
  $output = "";

  switch ($section) {
    case 'admin/system/modules#description':
      $output = t("Enables the organization of content into categories.");
      break;
    case 'admin/taxonomy':
      $output = t("The taxonomy module allows you to classify content into categories and subcategories; it allows multiple lists of categories for classification (controlled vocabularies) and offers the possibility of creating thesauri (controlled vocabularies that indicate the relationship of terms) and taxonomies (controlled vocabularies where relationships are indicated hierarchically). To delete a term choose \"edit term\". To delete a vocabulary, and all its terms, choose \"edit vocabulary\".");
      break;
    case 'admin/taxonomy/add/vocabulary':
      $output = t("When you create a controlled vocabulary you are creating a set of terms to use for describing content (known as descriptors in indexing lingo).  Drupal allows you to describe each node type (blog, story, etc.) using one or many of these terms. For simple implementations, you might create a set of categories without subcategories, similar to Slashdot.org's or Kuro5hin.org's sections. For more complex implementations, you might create a hierarchical list of categories.");
      break;
    case 'admin/help#taxonomy':
      $output .= t("
      <h3>Background</h3>
      <p>Taxonomy is the study of classification. Drupal's taxonomy module allows you to define categories which are used to classify co