--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/includes/path.inc	Tue Dec 23 14:28:28 2008 +0100
@@ -0,0 +1,242 @@
+<?php
+// $Id: path.inc,v 1.19 2007/11/04 16:42:45 goba Exp $
+
+/**
+ * @file
+ * Functions to handle paths in Drupal, including path aliasing.
+ *
+ * These functions are not loaded for cached pages, but modules that need
+ * to use them in hook_init() or hook exit() can make them available, by
+ * executing "drupal_bootstrap(DRUPAL_BOOTSTRAP_PATH);".
+ */
+
+/**
+ * Initialize the $_GET['q'] variable to the proper normal path.
+ */
+function drupal_init_path() {
+  if (!empty($_GET['q'])) {
+    $_GET['q'] = drupal_get_normal_path(trim($_GET['q'], '/'));
+  }
+  else {
+    $_GET['q'] = drupal_get_normal_path(variable_get('site_frontpage', 'node'));
+  }
+}
+
+/**
+ * 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 = '') {
+  global $language;
+  // $map is an array with language keys, holding arrays of Drupal paths to alias relations
+  static $map = array(), $no_src = array(), $count;
+
+  $path_language = $path_language ? $path_language : $language->language;
+
+  // Use $count to avoid looking up paths in subsequent calls if there simply are no aliases
+  if (!isset($count)) {
+    $count = db_result(db_query('SELECT COUNT(pid) FROM {url_alias}'));
+  }
+
+  if ($action == 'wipe') {
+    $map = array();
+    $no_src = array();
+  }
+  elseif ($count > 0 && $path != '') {
+    if ($action == 'alias') {
+      if (isset($map[$path_language][$path])) {
+        return $map[$path_language][$path];
+      }
+      // Get the most fitting result falling back with alias without language
+      $alias = db_result(db_query("SELECT dst FROM {url_alias} WHERE src = '%s' AND language IN('%s', '') ORDER BY language DESC", $path, $path_language));
+      $map[$path_language][$path] = $alias;
+      return $alias;
+    }
+    // Check $no_src for this $path in case we've already determined that there
+    // isn't a path that has this alias
+    elseif ($action == 'source' && !isset($no_src[$path_language][$path])) {
+      // Look for the value $path within the cached $map
+      $src = '';
+      if (!isset($map[$path_language]) || !($src = array_search($path, $map[$path_language]))) {
+        // Get the most fitting result falling back with alias without language
+        if ($src = db_result(db_query("SELECT src FROM {url_alias} WHERE dst = '%s' AND language IN('%s', '') ORDER BY language DESC", $path, $path_language))) {
+          $map[$path_language][$src] = $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_src.
+          $no_src[$path_language][$path] = TRUE;
+        }
+      }
+      return $src;
+    }
+  }
+
+  return FALSE;
+}
+
+/**
+ * Given an internal Drupal path, return the alias set by the administrator.
+ *
+ * @param $path
+ *   An internal Drupal path.
+ * @param $path_language
+ *   An optional language code to look up the path in.
+ *
+ * @return
+ *   An aliased path if one was found, or the original path if no alias was
+ *   found.
+ */
+function drupal_get_path_alias($path, $path_language = '') {
+  $result = $path;
+  if ($alias = drupal_lookup_path('alias', $path, $path_language)) {
+    $result = $alias;
+  }
+  return $result;
+}
+
+/**
+ * Given a path alias, return the internal path it represents.
+ *
+ * @param $path
+ *   A Drupal path alias.
+ * @param $path_language
+ *   An optional language code to look up the path in.
+ *
+ * @return
+ *   The internal path represented by the alias, or the original alias if no
+ *   internal path was found.
+ */
+function drupal_get_normal_path($path, $path_language = '') {
+  $result = $path;
+  if ($src = drupal_lookup_path('source', $path, $path_language)) {
+    $result = $src;
+  }
+  if (function_exists('custom_url_rewrite_inbound')) {
+    // Modules may alter the inbound request path by reference.
+    custom_url_rewrite_inbound($result, $path, $path_language);
+  }
+  return $result;
+}
+
+/**
+ * Return a component of the current Drupal path.
+ *
+ * When viewing a page at the path "admin/content/types", for example, arg(0)
+ * would return "admin", arg(1) would return "content", and arg(2) would return
+ * "types".
+ *
+ * Avoid use of this function where possible, as resulting code is hard to read.
+ * Instead, attempt to use named arguments in menu callback functions. See the
+ * explanation in menu.inc for how to construct callbacks that take arguments.
+ *
+ * @param $index
+ *   The index of the component, where each component is separated by a '/'
+ *   (forward-slash), and where the first component has an index of 0 (zero).
+ *
+ * @return
+ *   The component specified by $index, or NULL if the specified component was
+ *   not found.
+ */
+function arg($index = NULL, $path = NULL) {
+  static $arguments;
+
+  if (!isset($path)) {
+    $path = $_GET['q'];
+  }
+  if (!isset($arguments[$path])) {
+    $arguments[$path] = explode('/', $path);
+  }
+  if (!isset($index)) {
+    return $arguments[$path];
+  }
+  if (isset($arguments[$path][$index])) {
+    return $arguments[$path][$index];
+  }
+}
+
+/**
+ * Get the title of the current page, for display on the page and in the title bar.
+ *
+ * @return
+ *   The current page's title.
+ */
+function drupal_get_title() {
+  $title = drupal_set_title();
+
+  // during a bootstrap, menu.inc is not included and thus we cannot provide a title
+  if (!isset($title) && function_exists('menu_get_active_title')) {
+    $title = check_plain(menu_get_active_title());
+  }
+
+  return $title;
+}
+
+/**
+ * Set the title of the current page, for display on the page and in the title bar.
+ *
+ * @param $title
+ *   Optional string value to assign to the page title; or if set to NULL
+ *   (default), leaves the current title unchanged.
+ *
+ * @return
+ *   The updated title of the current page.
+ */
+function drupal_set_title($title = NULL) {
+  static $stored_title;
+
+  if (isset($title)) {
+    $stored_title = $title;
+  }
+  return $stored_title;
+}
+
+/**
+ * Check if the current page is the front page.
+ *
+ * @return
+ *   Boolean value: TRUE if the current page is the front page; FALSE if otherwise.
+ */
+function drupal_is_front_page() {
+  // As drupal_init_path updates $_GET['q'] with the 'site_frontpage' path,
+  // we can check it against the 'site_frontpage' variable.
+  return $_GET['q'] == drupal_get_normal_path(variable_get('site_frontpage', 'node'));
+}
+
+/**
+ * Check if a path matches any pattern in a set of patterns.
+ *
+ * @param $path
+ *   The path to match.
+ * @param $patterns
+ *   String containing a set of patterns separated by \n, \r or \r\n.
+ *
+ * @return
+ *   Boolean value: TRUE if the path matches a pattern, FALSE otherwise.
+ */
+function drupal_match_path($path, $patterns) {
+  static $regexps;
+
+  if (!isset($regexps[$patterns])) {
+    $regexps[$patterns] = '/^('. preg_replace(array('/(\r\n?|\n)/', '/\\\\\*/', '/(^|\|)\\\\<front\\\\>($|\|)/'), array('|', '.*', '\1'. preg_quote(variable_get('site_frontpage', 'node'), '/') .'\2'), preg_quote($patterns, '/')) .')$/';
+  }
+  return preg_match($regexps[$patterns], $path);
+}