drupal_lookup_path

• Drupal 4.7
• Drupal 5
• Drupal 6
• Drupal 7

Versions

4.7 – 5

drupal_lookup_path($action, $path = '')

6 – 7

drupal_lookup_path($action, $path = '', $path_language = '')

Given an alias, return its Drupal system URL if one exists. Given a Drupal system URL return one of its aliases if such a one exists. Otherwise, return FALSE.

Parameters

$action One of the following values:

• wipe: delete the alias cache.
• alias: return an alias for a given Drupal system path (if one exists).
• source: return the Drupal system URL for a path alias (if one exists).

$path The path to investigate for corresponding aliases or system URLs.

$path_language Optional language code to search the path with. Defaults to the page language. If there's no path defined for that language it will search paths without language.

Return value

Either a Drupal system path, an aliased path, or FALSE if no path was found.

Code

includes/path.inc, line 45

<?php
function drupal_lookup_path($action, $path = '', $path_language = '') {
  global $language;
  // Use the advanced drupal_static() pattern, since this is called very often.
  static $drupal_static = array();
  isset($drupal_static[__FUNCTION__]) || ($drupal_static[__FUNCTION__] = &drupal_static(__FUNCTION__));
  $cache = &$drupal_static[__FUNCTION__];

  if (!isset($cache)) {
    $cache = array(
      'map' => array(),
      'no_source' => array(),
      'whitelist' => NULL,
      'system_paths' => array(),
      'no_aliases' => array(),
      'first_call' => TRUE,
    );
  }

  // Retrieve the path alias whitelist.
  if (!isset($cache['whitelist'])) {
    $cache['whitelist'] = variable_get('path_alias_whitelist', NULL);
    if (!isset($cache['whitelist'])) {
      $cache['whitelist'] = drupal_path_alias_whitelist_rebuild();
    }
  }

  $path_language = $path_language ? $path_language : $language->language;

  if ($action == 'wipe') {
    $cache = array();
    $cache['whitelist'] = drupal_path_alias_whitelist_rebuild();
  }
  elseif ($cache['whitelist'] && $path != '') {
    if ($action == 'alias') {
      // During the first call to drupal_lookup_path() per language, load the
      // expected system paths for the page from cache.
      if (!empty($cache['first_call'])) {
        $cache['first_call'] = FALSE;

        $cache['map'][$path_language] = array();
        // Load system paths from cache.
        $cid = current_path();
        if ($cached = cache_get($cid, 'cache_path')) {
          $cache['system_paths'] = $cached->data;
          // Now fetch the aliases corresponding to these system paths.
          // We order by ASC and overwrite array keys to ensure the correct
          // alias is used when there are multiple aliases per path.
          $cache['map'][$path_language] = db_query("SELECT source, alias FROM {url_alias} WHERE source IN (:system) AND language IN (:language, '') ORDER BY language ASC, pid ASC", array(
            ':system' => $cache['system_paths'],
            ':language' => $path_language
          ))->fetchAllKeyed();
          // Keep a record of paths with no alias to avoid querying twice.
          $cache['no_aliases'][$path_language] = array_flip(array_diff_key($cache['system_paths'], array_keys($cache['map'][$path_language])));
        }
      }
      // If the alias has already been loaded, return it.
      if (isset($cache['map'][$path_language][$path])) {
        return $cache['map'][$path_language][$path];
      }
      // Check the path whitelist, if the top_level part before the first /
      // is not in the list, then there is no need to do anything further,
      // it is not in the database.
      elseif (!isset($cache['whitelist'][strtok($path, '/')])) {
        return FALSE;
      }
      // For system paths which were not cached, query aliases individually.
      else if (!isset($cache['no_aliases'][$path_language][$path])) {
        // Get the most fitting result falling back with alias without language
        $alias = db_query("SELECT alias FROM {url_alias} WHERE source = :source AND language IN (:language, '') ORDER BY language DESC, pid DESC", array(
          ':source' => $path,
          ':language' => $path_language
        ))->fetchField();
        $cache['map'][$path_language][$path] = $alias;
        return $alias;
      }
    }
    // Check $no_source for this $path in case we've already determined that there
    // isn't a path that has this alias
    elseif ($action == 'source' && !isset($cache['no_source'][$path_language][$path])) {
      // Look for the value $path within the cached $map
      $source = '';
      if (!isset($cache['map'][$path_language]) || !($source = array_search($path, $cache['map'][$path_language]))) {
        // Get the most fitting result falling back with alias without language
        if ($source = db_query("SELECT source FROM {url_alias} WHERE alias = :alias AND language IN (:language, '') ORDER BY language DESC, pid DESC", array(
                     ':alias' => $path,
                     ':language' => $path_language))
            ->fetchField()) {
          $cache['map'][$path_language][$source] = $path;
        }
        else {
          // We can't record anything into $map because we do not have a valid
          // index and there is no need because we have not learned anything
          // about any Drupal path. Thus cache to $no_source.
          $cache['no_source'][$path_language][$path] = TRUE;
        }
      }
      return $source;
    }
  }

  return FALSE;
}
?>

Login or register to post comments