taxonomy.module

<?php
// $Id$

/**
 * @file
 * Enables the organization of content into categories.
 */

/**
 * Implementation of hook_perm().
 */
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 == 'taxonomy terms' && $node != NULL) {
    $links = array();
    if (array_key_exists('taxonomy', $node)) {
      foreach ($node->taxonomy as $term) {
        $links['taxonomy_term_'. $term->tid] = array(
          'title' => $term->name,
          'href' => taxonomy_term_path($term),
          'attributes' => array('rel' => 'tag', 'title' => strip_tags($term->description))
        );
      }
    }

    // We call this hook again because some modules and themes call taxonomy_link('taxonomy terms') directly
    foreach (module_implements('link_alter') AS $module) {
      $function = $module .'_link_alter';
      $function($node, $links);
    }

    return $links;
  }
}

function taxonomy_term_path($term) {
  $vocabulary = taxonomy_get_vocabulary($term->vid);
  if ($vocabulary->module != 'taxonomy' && $path = module_invoke($vocabulary->module, 'term_path', $term)) {
    return $path;
  }
  return 'taxonomy/term/'. $term->tid;
}

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

  if ($may_cache) {
    $items[] = array('path' => 'admin/content/taxonomy',
      'title' => t('categories'),
      'description' => t('Create vocabularies and terms to categorize your content.'),
      'callback' => 'taxonomy_overview_vocabularies',
      'access' => user_access('administer taxonomy'));

    $items[] = array('path' => 'admin/content/taxonomy/list',
      'title' => t('list'),
      'type' => MENU_DEFAULT_LOCAL_TASK,
      'weight' => -10);

    $items[] = array('path' => 'admin/content/taxonomy/add/vocabulary',
      'title' => t('add vocabulary'),
      'callback' => 'taxonomy_admin_vocabulary_edit',
      'access' => user_access('administer taxonomy'),
      'type' => MENU_LOCAL_TASK);

    $items[] = array('path' => 'admin/content/taxonomy/edit/vocabulary',
      'title' => t('edit vocabulary'),
      'callback' => 'taxonomy_admin_vocabulary_edit',
      'access' => user_access('administer taxonomy'),
      'type' => MENU_CALLBACK);

    $items[] = array('path' => 'admin/content/taxonomy/edit/term',
      'title' => t('edit term'),
      'callback' => 'taxonomy_admin_term_edit',
      'access' => user_access('administer taxonomy'),
      'type' => MENU_CALLBACK);

    $items[] = array('path' => 'taxonomy/term',
      'title' => t('taxonomy term'),
      'callback' => 'taxonomy_term_page',
      'access' => user_access('access content'),
      'type' => MENU_CALLBACK);

    $items[] = array('path' => 'taxonomy/autocomplete',
      'title' => t('autocomplete taxonomy'),
      'callback' => 'taxonomy_autocomplete',
      'access' => user_access('access content'),
      'type' => MENU_CALLBACK);
  }
  else {
    if (is_numeric(arg(3))) {
      $items[] = array('path' => 'admin/content/taxonomy/' . arg(3),
        'title' => t('list terms'),
        'callback' => 'taxonomy_overview_terms',
        'callback arguments' => array(arg(3)),
        'access' => user_access('administer taxonomy'),
        'type' => MENU_CALLBACK);

      $items[] = array('path' => 'admin/content/taxonomy/' . arg(3) . '/list',
        'title' => t('list'),
        'type' => MENU_DEFAULT_LOCAL_TASK,
        'weight' => -10);

      $items[] = array('path' => 'admin/content/taxonomy/' . arg(3) . '/add/term',
        'title' => t('add term'),
        'callback' => 'taxonomy_form_term',
        'callback arguments' => array(array('vid' => arg(3))),
        'access' => user_access('administer taxonomy'),
        'type' => MENU_LOCAL_TASK);
    }
  }

  return $items;
}

/**
 * List and manage vocabularies.
 */
function taxonomy_overview_vocabularies() {
  $vocabularies = taxonomy_get_vocabularies();
  $rows = array();
  foreach ($vocabularies as $vocabulary) {
    $types = array();
    foreach ($vocabulary->nodes as $type) {
      $node_type = node_get_name($type);
      $types[] = $node_type ? $node_type : $type;
    }
    $rows[] = array('name' => check_plain($vocabulary->name),
      'type' => implode(', ', $types),
      'edit' => l(t('edit vocabulary'), "admin/content/taxonomy/edit/vocabulary/$vocabulary->vid"),
      'list' => l(t('list terms'), "admin/content/taxonomy/$vocabulary->vid"),
      'add' => l(t('add terms'), "admin/content/taxonomy/$vocabulary->vid/add/term")
    );
  }
  if (empty($rows)) {
    $rows[] = array(array('data' => t('No categories available.'), 'colspan' => '5', 'class' => 'message'));
  }
  $header = array(t('Name'), t('Type'), array('data' => t('Operations'), 'colspan' => '3'));

  return theme('table', $header, $rows, array('id' => 'taxonomy'));
}

/**
 * Display a tree of all the terms in a vocabulary, with options to edit
 * each one.
 */
function taxonomy_overview_terms($vid) {
  $destination = drupal_get_destination();

  $header = array(t('Name'), t('Operations'));
  $vocabulary = taxonomy_get_vocabulary($vid);

  drupal_set_title(check_plain($vocabulary->name));
  $start_from      = $_GET['page'] ? $_GET['page'] : 0;
  $total_entries   = 0;  // total count for pager
  $page_increment  = 25; // number of tids per page
  $displayed_count = 0;  // number of tids shown

  $tree = taxonomy_get_tree($vocabulary->vid);
  foreach ($tree as $term) {
    $total_entries++; // we're counting all-totals, not displayed
    if (($start_from && ($start_from * $page_increment) >= $total_entries) || ($displayed_count == $page_increment)) { continue; }
    $rows[] = array(_taxonomy_depth($term->depth) . ' ' . l($term->name, "taxonomy/term/$term->tid"), l(t('edit'), "admin/content/taxonomy/edit/term/$term->tid", array(), $destination));
    $displayed_count++; // we're counting tids displayed
  }

  if (!$rows) {
    $rows[] = array(array('data' => t('No terms available.'), 'colspan' => '2'));
  }

  $GLOBALS['pager_page_array'][] = $start_from;  // FIXME
  $GLOBALS['pager_total'][] = intval($total_entries / $page_increment) + 1; // FIXME

  if ($total_entries >= $page_increment) {
    $rows[] = array(array('data' => theme('pager', NULL, $page_increment), 'colspan' => '2'));
  }

  return theme('table', $header, $rows, array('id' => 'taxonomy'));
}

/**
 * Display form for adding and editing vocabularies.
 */
function taxonomy_form_vocabulary($edit = array()) {
  $form['name'] = array('#type' => 'textfield',
    '#title' => t('Vocabulary name'),
    '#default_value' => $edit['name'],
    '#maxlength' => 64,
    '#description' => t('The name for this vocabulary. Example: "Topic".'),
    '#required' => TRUE,
  );
  $form['description'] = array('#type' => 'textarea',
    '#title' => t('Description'),
    '#default_value' => $edit['description'],
    '#description' => t('Description of the vocabulary; can be used by modules.'),
  );
  $form['help'] = array('#type' => 'textfield',
    '#title' => t('Help text'),
    '#default_value' => $edit['help'],
    '#description' => t('Instructions to present to the user when choosing a term.'),
  );
  $form['nodes'] = array('#type' => 'checkboxes',
    '#title' => t('Types'),
    '#default_value' => $edit['nodes'],
    '#options' => node_get_types(),
    '#description' => t('A list of node types you want to associate with this vocabulary.'),
    '#required' => TRUE,
  );
  $form['hierarchy'] = array('#type' => 'radios',
    '#title' => t('Hierarchy'),
    '#default_value' => $edit['hierarchy'],
    '#options' => array(t('Disabled'), t('Single'), t('Multiple')),
    '#description' => t('Allows <a href="%help-url">a tree-like hierarchy</a> between terms of this vocabulary.', array('%help-url' => url('admin/help/taxonomy', NULL, NULL, 'hierarchy'))),
  );
  $form['relations'] = array('#type' => 'checkbox',
    '#title' => t('Related terms'),
    '#default_value' => $edit['relations'],
    '#description' => t('Allows <a href="%help-url">related terms</a> in this vocabulary.', array('%help-url' => url('admin/help/taxonomy', NULL, NULL, 'related-terms'))),
  );
  $form['tags'] = array('#type' => 'checkbox',
    '#title' => t('Free tagging'),
    '#default_value' => $edit['tags'],
    '#description' => t('Content is categorized by typing terms instead of choosing from a list.'),
  );
  $form['multiple'] = array('#type' => 'checkbox',
    '#title' => t('Multiple select'),
    '#default_value' => $edit['multiple'],
    '#description' => t('Allows nodes to have more than one term from this vocabulary (always true for free tagging).'),
  );
  $form['required'] = array('#type' => 'checkbox',
    '#title' => t('Required'),
    '#default_value' => $edit['required'],
    '#description' => t('If enabled, every node <strong>must</strong> have at least one term in this vocabulary.'),
  );
  $form['weight'] = array('#type' => 'weight',
    '#title' => t('Weight'),
    '#default_value' => $edit['weight'],
    '#description' => t('In listings, the heavier vocabularies will sink and the lighter vocabularies will be positioned nearer the top.'),
  );

  // Add extra vocabulary form elements.
  $extra = module_invoke_all('taxonomy', 'form', 'vocabulary');
  if (is_array($extra)) {
    foreach ($extra as $key => $element) {
      $extra[$key]['#weight'] = isset($extra[$key]['#weight']) ? $extra[$key]['#weight'] : -18;
    }
    $form = array_merge($form, $extra);
  }

  $form['submit'] = array('#type' => 'submit', '#value' => t('Submit'));
  if ($edit['vid']) {
    $form['delete'] = array('#type' => 'submit', '#value' => t('Delete'));
    $form['vid'] = array('#type' => 'value', '#value' => $edit['vid']);
    $form['module'] = array('#type' => 'value', '#value' => $edit['module']);
  }
  return drupal_get_form('taxonomy_form_vocabulary', $form);
}

/**
 * Accept the form submission for a vocabulary and save the results.
 */
function taxonomy_form_vocabulary_submit($form_id, $form_values) {
  // Fix up the nodes array to remove unchecked nodes.
  $form_values['nodes'] = array_filter($form_values['nodes']);
  switch (taxonomy_save_vocabulary($form_values)) {
  case SAVED_NEW:
    drupal_set_message(t('Created new vocabulary %name.', array('%name' => theme('placeholder', $form_values['name']))));
    break;
  case SAVED_UPDATED:
    drupal_set_message(t('Updated vocabulary %name.', array('%name' => theme('placeholder', $form_values['name']))));
    break;
  }
  return 'admin/content/taxonomy';
}

function taxonomy_save_vocabulary(&$edit) {
  $edit['nodes'] = empty($edit['nodes']) ? array() : $edit['nodes'];

  if ($edit['vid'] && $edit['name']) {
    db_query("UPDATE {vocabulary} SET name = '%s', description = '%s', help = '%s', multiple = %d, required = %d, hierarchy = %d, relations = %d, tags = %d, weight = %d, module = '%s' WHERE vid = %d", $edit['name'], $edit['description'], $edit['help'], $edit['multiple'], $edit['required'], $edit['hierarchy'], $edit['relations'], $edit['tags'], $edit['weight'], isset($edit['module']) ? $edit['module'] : 'taxonomy', $edit['vid']);
    db_query("DELETE FROM {vocabulary_node_types} WHERE vid = %d", $edit['vid']);
    foreach ($edit['nodes'] as $type => $selected) {
      db_query("INSERT INTO {vocabulary_node_types} (vid, type) VALUES (%d, '%s')", $edit['vid'], $type);
    }
    module_invoke_all('taxonomy', 'update', 'vocabulary', $edit);
    $status = SAVED_UPDATED;
  }
  else if ($edit['vid']) {
    $status = taxonomy_del_vocabulary($edit['vid']);
  }
  else {
    $edit['vid'] = db_next_id('{vocabulary}_vid');
    db_query("INSERT INTO {vocabulary} (vid, name, description, help, multiple, required, hierarchy, relations, tags, weight, module) VALUES (%d, '%s', '%s', '%s', %d, %d, %d, %d, %d, %d, '%s')", $edit['vid'], $edit['name'], $edit['description'], $edit['help'], $edit['multiple'], $edit['required'], $edit['hierarchy'], $edit['relations'], $edit['tags'], $edit['weight'], isset($edit['module']) ? $edit['module'] : 'taxonomy');
    foreach ($edit['nodes'] as $type => $selected) {
      db_query("INSERT INTO {vocabulary_node_types} (vid, type) VALUES (%d, '%s')", $edit['vid'], $type);
    }
    module_invoke_all('taxonomy', 'insert', 'vocabulary', $edit);
    $status = SAVED_NEW;
  }

  cache_clear_all();

  return $status;
}

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

  db_query('DELETE FROM {vocabulary} WHERE vid = %d', $vid);
  db_query('DELETE FROM {vocabulary_node_types} 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 SAVED_DELETED;
}

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

  $form['type'] = array('#type' => 'value', '#value' => 'vocabulary');
  $form['vid'] = array('#type' => 'value', '#value' => $vid);
  $form['name'] = array('#type' => 'value', '#value' => $vocabulary->name);
  return confirm_form('taxonomy_vocabulary_confirm_delete', $form,
                  t('Are you sure you want to delete the vocabulary %title?',
                  array('%title' => theme('placeholder', $vocabulary->name))),
                  'admin/content/taxonomy', t('Deleting a vocabulary will delete all the terms in it. This action cannot be undone.'),
                  t('Delete'),
                  t('Cancel'));
}

function taxonomy_vocabulary_confirm_delete_submit($form_id, $form_values) {
  $status = taxonomy_del_vocabulary($form_values['vid']);
  drupal_set_message(t('Deleted vocabulary %name.', array('%name' => theme('placeholder', $form_values['name']))));
  return 'admin/content/taxonomy';
}

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

  $form['name'] = array('#type' => 'textfield', '#title' => t('Term name'), '#default_value' => $edit['name'], '#maxlength' => 64, '#description' => t('The name for this term. Example: "Linux".'), '#required' => TRUE);

  $form['description'] = array('#type' => 'textarea', '#title' => t('Description'), '#default_value' => $edit['description'], '#description' => 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']);

    // A term can't be the child of itself, nor of its children.
    foreach ($children as $child) {
      $exclude[] = $child->tid;
    }
    $exclude[] = $edit['tid'];

    if ($vocabulary->hierarchy == 1) {
      $form['parent'] = _taxonomy_term_select(t('Parent'), 'parent', $parent, $vocabulary_id, l(t('Parent term'), 'admin/help/taxonomy', NULL, NULL, 'parent') .'.', 0, '<'. t('root') .'>', $exclude);
    }
    elseif ($vocabulary->hierarchy == 2) {
      $form['parent'] = _taxonomy_term_select(t('Parents'), 'parent', $parent, $vocabulary_id, l(t('Parent terms'), 'admin/help/taxonomy', NULL, NULL, 'parent') .'.', 1, '<'. t('root') .'>', $exclude);
    }
  }

  if ($vocabulary->relations) {
    $form['relations'] = _taxonomy_term_select(t('Related terms'), 'relations', array_keys(taxonomy_get_related($edit['tid'])), $vocabulary_id, NULL, 1, '<'. t('none') .'>', array($edit['tid']));
  }

  $form['synonyms'] = array('#type' => 'textarea', '#title' => t('Synonyms'), '#default_value' => implode("\n", taxonomy_get_synonyms($edit['tid'])), '#description' => t('<a href="%help-url">Synonyms</a> of this term, one synonym per line.', array('%help-url' => url('admin/help/taxonomy', NULL, NULL, 'synonyms'))));
  $form['weight'] = array('#type' => 'weight', '#title' => t('Weight'), '#default_value' => $edit['weight'], '#description' => t('In listings, the heavier terms will sink and the lighter terms will be positioned nearer the top.'));

  // Add extra term form elements.
  $extra = module_invoke_all('taxonomy', 'term', 'vocabulary');
  if (is_array($extra)) {
    foreach ($extra as $key => $element) {
      $extra[$key]['#weight'] = isset($extra[$key]['#weight']) ? $extra[$key]['#weight'] : -18;
    }
    $form = array_merge($form, $extra);
  }


  $form['vid'] = array('#type' => 'value', '#value' => $vocabulary->vid);
  $form['submit'] = array('#type' => 'submit', '#value' => t('Submit'));

  if ($edit['tid']) {
    $form['delete'] = array('#type' => 'submit', '#value' => t('Delete'));
    $form['tid'] = array('#type' => 'value', '#value' => $edit['tid']);
  }
  else {
    $form['destination'] = array('#type' => 'hidden', '#value' => $_GET['q']);
  }

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

/**
 * Accept the form submission for a taxonomy term and save the result.
 */
function taxonomy_form_term_submit($form_id, $form_values) {
  switch (taxonomy_save_term($form_values)) {
    case SAVED_NEW:
      drupal_set_message(t('Created new term %term.', array('%term' => theme('placeholder', $form_values['name']))));
      break;
    case SAVED_UPDATED:
      drupal_set_message(t('The term %term has been updated.', array('%term' => theme('placeholder', $form_values['name']))));
      break;
  }
  return 'admin/content/taxonomy';
}

function taxonomy_save_term(&$edit) {
  if ($edit['tid'] && $edit['name']) {
    db_query("UPDATE {term_data} SET name = '%s', description = '%s', weight = %d WHERE tid = %d", $edit['name'], $edit['description'], $edit['weight'], $edit['tid']);
    module_invoke_all('taxonomy', 'update', 'term', $edit);
    $status = SAVED_UPDATED;
  }
  else if ($edit['tid']) {
    return taxonomy_del_term($edit['tid']);
  }
  else {
    $edit['tid'] = db_next_id('{term_data}_tid');
    db_query("INSERT INTO {term_data} (tid, name, description, vid, weight) VALUES (%d, '%s', '%s', %d, %d)", $edit['tid'], $edit['name'], $edit['description'], $edit['vid'], $edit['weight']);
    module_invoke_all('taxonomy', 'insert', 'term', $edit);
    $status = SAVED_NEW;
  }

  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);
      }
    }
  }

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

  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();

  return $status;
}

function taxonomy_del_term($tid) {
  $tids = array($tid);
  while ($tids) {
    $children_tids = $orphans = array();
    foreach ($tids as $tid) {
      // See if any of the term's children are about to be become orphans:
      if ($children = taxonomy_get_children($tid)) {
        foreach ($children as $child) {
          // If the term has multiple parents, we don't delete it.
          $parents = taxonomy_get_parents($child->tid);
          if (count($parents) == 1) {
            $orphans[] = $child->tid;
          }
        }
      }

      $term = (array) taxonomy_get_term($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);
    }

    $tids = $orphans;
  }

  cache_clear_all();

  return SAVED_DELETED;
}

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

  $form['type'] = array('#type' => 'value', '#value' => 'term');
  $form['name'] = array('#type' => 'value', '#value' => $term->name);
  $form['tid'] = array('#type' => 'value', '#value' => $tid);
  return confirm_form('taxonomy_term_confirm_delete', $form,
                  t('Are you sure you want to delete the term %title?',
                  array('%title' => theme('placeholder', $term->name))),
                  'admin/content/taxonomy',
                  t('Deleting a term will delete all its children if there are any. This action cannot be undone.'),
                  t('Delete'),
                  t('Cancel'));
}

function taxonomy_term_confirm_delete_submit($form_id, $form_values) {
  taxonomy_del_term($form_values['tid']);
  drupal_set_message(t('Deleted term %name.', array('%name' => theme('placeholder', $form_values['name']))));
  return 'admin/content/taxonomy';
}

/**
 * Generate a form element for selecting terms from a vocabulary.
 */
function taxonomy_form($vid, $value = 0, $help = NULL, $name = 'taxonomy') {
  $vocabulary = taxonomy_get_vocabulary($vid);
  $help = ($help) ? $help : $vocabulary->help;
  if ($vocabulary->required) {
    $blank = 0;
  }
  else {
    $blank = '<'. t('none') .'>';
  }

  return _taxonomy_term_select(check_plain($vocabulary->name), $name, $value, $vid, $help, intval($vocabulary->multiple), $blank);
}

/**
 * Generate a set of options for selecting a term from all vocabularies. Can be
 * passed to form_select.
 */
function taxonomy_form_all($free_tags = 0) {
  $vocabularies = taxonomy_get_vocabularies();
  $options = array();
  foreach ($vocabularies as $vid => $vocabulary) {
    if ($vocabulary->tags && !$free_tags) { continue; }
    $tree = taxonomy_get_tree($vid);
    $options[$vocabulary->name] = array();
    if ($tree) {
      foreach ($tree as $term) {
        $options[$vocabulary->name][$term->tid] = _taxonomy_depth($term->depth, '-') . $term->name;
      }
    }
  }
  return $options;
}

/**
 * Return an array of all vocabulary objects.
 *
 * @param $type
 *   If set, return only those vocabularies associated with this node type.
 */
function taxonomy_get_vocabularies($type = NULL) {
  if ($type) {
    $result = db_query(db_rewrite_sql("SELECT v.vid, v.*, n.type FROM {vocabulary} v LEFT JOIN {vocabulary_node_types} n ON v.vid = n.vid WHERE n.type = '%s' ORDER BY v.weight, v.name", 'v', 'vid'), $type);
  }
  else {
    $result = db_query(db_rewrite_sql('SELECT v.*, n.type FROM {vocabulary} v LEFT JOIN {vocabulary_node_types} n ON v.vid = n.vid ORDER BY v.weight, v.name', 'v', 'vid'));
  }

  $vocabularies = array();
  $node_types = array();
  while ($voc = db_fetch_object($result)) {
    $node_types[$voc->vid][] = $voc->type;
    unset($voc->type);
    $voc->nodes = $node_types[$voc->vid];
    $vocabularies[$voc->vid] = $voc;
  }

  return $vocabularies;
}

/**
 * Generate a form for selecting terms to associate with a node.
 */
function taxonomy_form_alter($form_id, &$form) {
  if (isset($form['type']) && $form['type']['#value'] .'_node_form' == $form_id) {
    $node = $form['#node'];

    if (!isset($node->taxonomy)) {
      if ($node->nid) {
        $terms = taxonomy_node_get_terms($node->nid);
      }
      else {
        $terms = array();
      }
    }
    else {
      $terms = $node->taxonomy;
    }

    $c = db_query(db_rewrite_sql("SELECT v.* FROM {vocabulary} v INNER JOIN {vocabulary_node_types} n ON v.vid = n.vid WHERE n.type = '%s' ORDER BY v.weight, v.name", 'v', 'vid'), $node->type);

    while ($vocabulary = db_fetch_object($c)) {
      if ($vocabulary->tags) {
        $typed_terms = array();
        foreach ($terms as $term) {
          // Extract terms belonging to the vocabulary in question.
          if ($term->vid == $vocabulary->vid) {

            // Commas and quotes in terms are special cases, so encode 'em.
            if (preg_match('/,/', $term->name) || preg_match('/"/', $term->name)) {
              $term->name = '"'.preg_replace('/"/', '""', $term->name).'"';
            }

            $typed_terms[] = $term->name;
          }
        }
        $typed_string = implode(', ', $typed_terms) . (array_key_exists('tags', $terms) ? $terms['tags'][$vocabulary->vid] : NULL);

        if ($vocabulary->help) {
          $help = $vocabulary->help;
        }
        else {
          $help = t('A comma-separated list of terms describing this content. Example: funny, bungee jumping, "Company, Inc.".');
        }
        $form['taxonomy']['tags'][$vocabulary->vid] = array('#type' => 'textfield',
          '#title' => $vocabulary->name,
          '#description' => $help,
          '#required' => $vocabulary->required,
          '#default_value' => $typed_string,
          '#autocomplete_path' => 'taxonomy/autocomplete/'. $vocabulary->vid,
          '#weight' => $vocabulary->weight,
          '#maxlength' => 255,
        );
      }
      else {
        // Extract terms belonging to the vocabulary in question.
        $default_terms = array();
        foreach ($terms as $term) {
          if ($term->vid == $vocabulary->vid) {
            $default_terms[$term->tid] = $term;
          }
        }
        $form['taxonomy'][$vocabulary->vid] = taxonomy_form($vocabulary->vid, array_keys($default_terms), $vocabulary->help);
        $form['taxonomy'][$vocabulary->vid]['#weight'] = $vocabulary->weight;
        $form['taxonomy'][$vocabulary->vid]['#required'] = $vocabulary->required;
      }
    }
    if (isset($form['taxonomy'])) {
      $form['taxonomy'] += array('#type' => 'fieldset', '#title' => t('Categories'), '#collapsible' => TRUE, '#collapsed' => FALSE, '#tree' => TRUE, '#weight' => -3);
    }
  }
}

/**
 * Find all terms associated to the given node, within one vocabulary.
 */
function taxonomy_node_get_terms_by_vocabulary($nid, $vid, $key = 'tid') {
  $result = db_query(db_rewrite_sql('SELECT t.tid, t.* FROM {term_data} t INNER JOIN {term_node} r ON r.tid = t.tid WHERE t.vid = %d AND r.nid = %d ORDER BY weight', 't', 'tid'), $vid, $nid);
  $terms = array();
  while ($term = db_fetch_object($result)) {
    $terms[$term->$key] = $term;
  }
  return $terms;
}

/**
 * Find all terms associated to the given node, ordered by vocabulary and term weight.
 */
function taxonomy_node_get_terms($nid, $key = 'tid') {
  static $terms;

  if (!isset($terms[$nid])) {
    $result = db_query(db_rewrite_sql('SELECT t.* FROM {term_node} r INNER JOIN {term_data} t ON r.tid = t.tid INNER JOIN {vocabulary} v ON t.vid = v.vid WHERE r.nid = %d ORDER BY v.weight, t.weight, t.name', 't', 'tid'), $nid);
    $terms[$nid] = array();
    while ($term = db_fetch_object($result)) {
      $terms[$nid][$term->$key] = $term;
    }
  }
  return $terms[$nid];
}

/**
 * Make sure incoming vids are free tagging enabled.
 */
function taxonomy_node_validate(&$node) {
  if ($node->taxonomy) {
    $terms = $node->taxonomy;
    if ($terms['tags']) {
      foreach ($terms['tags'] as $vid => $vid_value) {
        $vocabulary = taxonomy_get_vocabulary($vid);
        if (!$vocabulary->tags) {
          // see form_get_error $key = implode('][', $element['#parents']);
          // on why this is the key
          form_set_error("taxonomy][tags][$vid", t('The %name vocabulary can not be modified in this way.', array('%name' => theme('placeholder', $vocabulary->name))));
        }
      }
    }
  }
}

/**
 * Save term associations for a given node.
 */
function taxonomy_node_save($nid, $terms) {
  taxonomy_node_delete($nid);

  // Free tagging vocabularies do not send their tids in the form,
  // so we'll detect them here and process them independently.
  if (isset($terms['tags'])) {
    $typed_input = $terms['tags'];
    unset($terms['tags']);

    foreach ($typed_input as $vid => $vid_value) {
      // This regexp allows the following types of user input:
      // this, "somecmpany, llc", "and ""this"" w,o.rks", foo bar
      $regexp = '%(?:^|,\ *)("(?>[^"]*)(?>""[^"]* )*"|(?: [^",]*))%x';
      preg_match_all($regexp, $vid_value, $matches);
      $typed_terms = array_unique($matches[1]);

      $inserted = array();
      foreach ($typed_terms as $typed_term) {
        // If a user has escaped a term (to demonstrate that it is a group,
        // or includes a comma or quote character), we remove the escape
        // formatting so to save the term into the DB as the user intends.
        $typed_term = str_replace('""', '"', preg_replace('/^"(.*)"$/', '\1', $typed_term));
        $typed_term = trim($typed_term);
        if ($typed_term == "") { continue; }

        // See if the term exists in the chosen vocabulary
        // and return the tid, otherwise, add a new record.
        $possibilities = taxonomy_get_term_by_name($typed_term);
        $typed_term_tid = NULL; // tid match if any.
        foreach ($possibilities as $possibility) {
          if ($possibility->vid == $vid) {
            $typed_term_tid = $possibility->tid;
          }
        }

        if (!$typed_term_tid) {
          $edit = array('vid' => $vid, 'name' => $typed_term);
          $status = taxonomy_save_term($edit);
          $typed_term_tid = $edit['tid'];
        }

        // Defend against duplicate, different cased tags
        if (!isset($inserted[$typed_term_tid])) {
          db_query('INSERT INTO {term_node} (nid, tid) VALUES (%d, %d)', $nid, $typed_term_tid);
          $inserted[$typed_term_tid] = TRUE;
        }
      }
    }
  }

  if (is_array($terms)) {
    foreach ($terms as $term) {
      if (is_array($term)) {
        foreach ($term as $tid) {
          if ($tid) {
            db_query('INSERT INTO {term_node} (nid, tid) VALUES (%d, %d)', $nid, $tid);
          }
        }
      }
      else if (is_object($term)) {
        db_query('INSERT INTO {term_node} (nid, tid) VALUES (%d, %d)', $nid, $term->tid);
      }
      else if ($term) {
        db_query('INSERT INTO {term_node} (nid, tid) VALUES (%d, %d)', $nid, $term);
      }
    }
  }
}

/**
 * Remove associations of a node to its terms.
 */
function taxonomy_node_delete($nid) {
  db_query('DELETE FROM {term_node} WHERE nid = %d', $nid);
}

/**
 * Find all term objects related to a given term ID.
 */
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();
  }
}

/**
 * Find all parents of a given term ID.
 */
function taxonomy_get_parents($tid, $key = 'tid') {
  if ($tid) {
    $result = db_query(db_rewrite_sql('SELECT t.tid, t.* FROM {term_data} t INNER JOIN {term_hierarchy} h ON h.parent = t.tid WHERE h.tid = %d ORDER BY weight, name', 't', 'tid'), $tid);
    $parents = array();
    while ($parent = db_fetch_object($result)) {
      $parents[$parent->$key] = $parent;
    }
    return $parents;
  }
  else {
    return array();
  }
}

/**
 * Find all ancestors of a given term ID.
 */
function taxonomy_get_parents_all($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;
}

/**
 * Find all children of a term ID.
 */
function taxonomy_get_children($tid, $vid = 0, $key = 'tid') {
  if ($vid) {
    $result = db_query(db_rewrite_sql('SELECT t.* FROM {term_data} t INNER JOIN {term_hierarchy} h ON h.tid = t.tid WHERE t.vid = %d AND h.parent = %d ORDER BY weight, name', 't', 'tid'), $vid, $tid);
  }
  else {
    $result = db_query(db_rewrite_sql('SELECT t.* FROM {term_data} t INNER JOIN {term_hierarchy} h ON h.tid = t.tid WHERE parent = %d ORDER BY weight, name', 't', 'tid'), $tid);
  }
  $children = array();
  while ($term = db_fetch_object($result)) {
    $children[$term->$key] = $term;
  }
  return $children;
}

/**
 * Create a hierarchical representation of a vocabulary.
 *
 * @param $vid
 *   Which vocabulary to generate the tree for.
 *
 * @param $parent
 *   The term ID under which to generate the tree. If 0, generate the tree
 *   for the entire vocabulary.
 *
 * @param $depth
 *   Internal use only.
 *
 * @param $max_depth
 *   The number of levels of the tree to return. Leave NULL to return all levels.
 *
 * @return
 *   An array of all term objects in the tree. Each term object is extended
 *   to have "depth" and "parents" attributes in addition to its normal ones.
 */
function taxonomy_get_tree($vid, $parent = 0, $depth = -1, $max_depth = NULL) {
  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($children[$vid])) {
    $children[$vid] = array();

    $result = db_query(db_rewrite_sql('SELECT t.tid, t.*, parent FROM {term_data} t INNER JOIN  {term_hierarchy} h ON t.tid = h.tid WHERE t.vid = %d ORDER BY weight, name', 't', 'tid'), $vid);
    while ($term = db_fetch_object($result)) {
      $children[$vid][$term->parent][] = $term->tid;
      $parents[$vid][$term->tid][] = $term->parent;
      $terms[$vid][$term->tid] = $term;
    }
  }

  $max_depth = (is_null($max_depth)) ? count($children[$vid]) : $max_depth;
  if ($children[$vid][$parent]) {
    foreach ($children[$vid][$parent] as $child) {
      if ($max_depth > $depth) {
        $terms[$vid][$child]->depth = $depth;
        // The "parent" attribute is not useful, as it would show one parent only.
        unset($terms[$vid][$child]->parent);
        $terms[$vid][$child]->parents = $parents[$vid][$child];
        $tree[] = $terms[$vid][$child];

        if ($children[$vid][$child]) {
          $tree = array_merge($tree, taxonomy_get_tree($vid, $child, $depth, $max_depth));
        }
      }
    }
  }

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

/**
 * Return an array of synonyms of the given term ID.
 */
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'];
    }