class languageHierarchyPaths in Language Hierarchy 7

@file Class to extend Drupal path handling with fallbacks by language hierarchy.

Hierarchy

• class \languageHierarchyPaths extends \DrupalPathinc

1 string reference to 'languageHierarchyPaths'

language_hierarchy_paths_enable in modules/language_hierarchy_paths/language_hierarchy_paths.install

Implements hook_enable().

File

modules/language_hierarchy_paths/languageHierarchyPaths.class.inc, line 7

Class to extend Drupal path handling with fallbacks by language hierarchy.

class languageHierarchyPaths extends DrupalPathinc {

  /**
   * 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.
   *
   * @param $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).
   * @param $path
   *   The path to investigate for corresponding aliases or system URLs.
   * @param $path_language
   *   Optional language code to search the path with. Defaults to the page language.
   *   If there's no path defined for that language it will search paths without
   *   language.
   *
   * @return
   *   Either a Drupal system path, an aliased path, or FALSE if no path was
   *   found.
   */
  function drupal_lookup_path($action, $path = '', $path_language = NULL) {
    global $language_url;

    // Use the advanced drupal_static() pattern, since this is called very often.
    static $drupal_static_fast;
    if (!isset($drupal_static_fast)) {
      $drupal_static_fast['cache'] =& drupal_static(__FUNCTION__);
    }
    $cache =& $drupal_static_fast['cache'];
    if (!isset($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'] = $this
          ->drupal_path_alias_whitelist_rebuild();
      }
    }

    // If no language is explicitly specified we default to the current URL
    // language. If we used a language different from the one conveyed by the
    // requested URL, we might end up being unable to check if there is a path
    // alias matching the URL path.
    $path_language = $path_language ? $path_language : $language_url->language;
    if ($action == 'wipe') {
      $cache = array();
      $cache['whitelist'] = $this
        ->drupal_path_alias_whitelist_rebuild();
    }
    elseif ($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 = $this
            ->current_path();
          if ($cached = cache_get($cid, 'cache_path')) {
            $cache['system_paths'] = $cached->data;

            // Now fetch the aliases corresponding to these system paths.
            $args = array(
              ':system' => $cache['system_paths'],
              ':language' => $path_language,
              ':language_none' => LANGUAGE_NONE,
            );

            // Always get the language-specific alias before the language-neutral
            // one. For example 'de' is less than 'und' so the order needs to be
            // ASC, while 'xx-lolspeak' is more than 'und' so the order needs to
            // be DESC. We also order by pid ASC so that fetchAllKeyed() returns
            // the most recently created alias for each source. Subsequent queries
            // using fetchField() must use pid DESC to have the same effect.
            // For performance reasons, the query builder is not used here.
            if ($path_language == LANGUAGE_NONE) {

              // Prevent PDO from complaining about a token the query doesn't use.
              unset($args[':language']);
              $result = db_query('SELECT source, alias FROM {url_alias} WHERE source IN (:system) AND language = :language_none ORDER BY pid ASC', $args);
            }
            elseif ($candidates = language_hierarchy_get_ancestors($path_language, TRUE)) {

              // Build up a select query that will get all source-alias pairs
              // for the cached paths, for all languages in the fallback tree.
              // Each language will be given a numerical index to be ordered by,
              // using the ORDER BY CASE ... END DESC construct. For example:
              // ORDER BY CASE
              //   WHEN language = 'pt-br' THEN 0
              //   WHEN language = 'pt' THEN 1
              //   WHEN language = 'und' THEN 2
              // END DESC
              // This ensures the most specific language comes last in the
              // result set (and most recent aliases come last within that due
              // to the secondary sort on pid). The use of fetchAllKeyed()
              // ensures that the last result for any source-alias pair is the
              // one that gets used.
              $candidates = array_keys($candidates);
              array_unshift($candidates, $path_language);
              $candidates[] = LANGUAGE_NONE;
              unset($args[':language'], $args[':language_none']);
              $query = "SELECT source, alias FROM {url_alias} WHERE source IN (:system) AND language IN (";
              $candidate_args = array();
              $order = "";
              foreach (array_values($candidates) as $i => $candidate_langcode) {
                $candidate_args[':candidate_' . $i] = $candidate_langcode;
                $order .= " WHEN language = :candidate_{$i} THEN {$i}";
              }
              $args += $candidate_args;
              $query .= implode(', ', array_keys($candidate_args)) . ") ORDER BY CASE {$order} END DESC, pid ASC";
              $result = db_query($query, $args);
            }
            elseif ($path_language > LANGUAGE_NONE) {
              $result = db_query('SELECT source, alias FROM {url_alias} WHERE source IN (:system) AND language IN (:language, :language_none) ORDER BY language ASC, pid ASC', $args);
            }
            else {
              $result = db_query('SELECT source, alias FROM {url_alias} WHERE source IN (:system) AND language IN (:language, :language_none) ORDER BY language DESC, pid ASC', $args);
            }
            $cache['map'][$path_language] = $result
              ->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][$path];
        }
        elseif (!isset($cache['whitelist'][strtok($path, '/')])) {
          return FALSE;
        }
        elseif (!isset($cache['no_aliases'][$path_language][$path])) {
          $args = array(
            ':source' => $path,
            ':language' => $path_language,
            ':language_none' => LANGUAGE_NONE,
          );

          // See the queries above.
          if ($path_language == LANGUAGE_NONE) {
            unset($args[':language']);
            $alias = db_query("SELECT alias FROM {url_alias} WHERE source = :source AND language = :language_none ORDER BY pid DESC", $args)
              ->fetchField();
          }
          elseif ($candidates = language_hierarchy_get_ancestors($path_language, TRUE)) {
            $candidates = array_keys($candidates);
            array_unshift($candidates, $path_language);
            $candidates[] = LANGUAGE_NONE;
            unset($args[':language'], $args[':language_none']);
            $query = "SELECT alias FROM {url_alias} WHERE source = :source AND language IN (";
            $candidate_args = array();
            $order = "";
            foreach (array_values($candidates) as $i => $candidate_langcode) {
              $candidate_args[':candidate_' . $i] = $candidate_langcode;
              $order .= " WHEN language = :candidate_{$i} THEN {$i}";
            }
            $args += $candidate_args;
            $query .= implode(', ', array_keys($candidate_args)) . ") ORDER BY CASE {$order} END ASC, pid DESC";
            $alias = db_query($query, $args)
              ->fetchField();
          }
          elseif ($path_language > LANGUAGE_NONE) {
            $alias = db_query("SELECT alias FROM {url_alias} WHERE source = :source AND language IN (:language, :language_none) ORDER BY language DESC, pid DESC", $args)
              ->fetchField();
          }
          else {
            $alias = db_query("SELECT alias FROM {url_alias} WHERE source = :source AND language IN (:language, :language_none) ORDER BY language ASC, pid DESC", $args)
              ->fetchField();
          }
          $cache['map'][$path_language][$path] = $alias;
          return $alias;
        }
      }
      elseif ($action == 'source' && !isset($cache['no_source'][$path_language][$path])) {

        // Look for the value $path within the cached $map
        $source = FALSE;
        if (!isset($cache['map'][$path_language]) || !($source = array_search($path, $cache['map'][$path_language]))) {
          $args = array(
            ':alias' => $path,
            ':language' => $path_language,
            ':language_none' => LANGUAGE_NONE,
          );

          // See the queries above.
          if ($path_language == LANGUAGE_NONE) {
            unset($args[':language']);
            $result = db_query("SELECT source FROM {url_alias} WHERE alias = :alias AND language = :language_none ORDER BY pid DESC", $args);
          }
          elseif ($candidates = language_hierarchy_get_ancestors($path_language, TRUE)) {
            $candidates = array_keys($candidates);
            array_unshift($candidates, $path_language);
            $candidates[] = LANGUAGE_NONE;
            unset($args[':language'], $args[':language_none']);
            $query = "SELECT source FROM {url_alias} WHERE alias = :alias AND language IN (";
            $candidate_args = array();
            $order = "";
            foreach (array_values($candidates) as $i => $candidate_langcode) {
              $candidate_args[':candidate_' . $i] = $candidate_langcode;
              $order .= " WHEN language = :candidate_{$i} THEN {$i}";
            }
            $args += $candidate_args;
            $query .= implode(', ', array_keys($candidate_args)) . ") ORDER BY CASE {$order} END ASC, pid DESC";
            $result = db_query($query, $args);
          }
          elseif ($path_language > LANGUAGE_NONE) {
            $result = db_query("SELECT source FROM {url_alias} WHERE alias = :alias AND language IN (:language, :language_none) ORDER BY language DESC, pid DESC", $args);
          }
          else {
            $result = db_query("SELECT source FROM {url_alias} WHERE alias = :alias AND language IN (:language, :language_none) ORDER BY language ASC, pid DESC", $args);
          }
          if ($source = $result
            ->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;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
languageHierarchyPaths::drupal_lookup_path		function	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.