Club Drupal

<?php

/**

 * @file

 * API for the Drupal menu system.

 */

/**

 * @defgroup menu Menu system

 * @{

 * Define the navigation menus, and route page requests to code based on URLs.

 *

 * The Drupal menu system drives both the navigation system from a user

 * perspective and the callback system that Drupal uses to respond to URLs

 * passed from the browser. For this reason, a good understanding of the

 * menu system is fundamental to the creation of complex modules. As a note,

 * this is related to, but separate from menu.module, which allows menus

 * (which in this context are hierarchical lists of links) to be customized from

 * the Drupal administrative interface.

 *

 * Drupal's menu system follows a simple hierarchy defined by paths.

 * Implementations of hook_menu() define menu items and assign them to

 * paths (which should be unique). The menu system aggregates these items

 * and determines the menu hierarchy from the paths. For example, if the

 * paths defined were a, a/b, e, a/b/c/d, f/g, and a/b/h, the menu system

 * would form the structure:

 * - a

 *   - a/b

 *     - a/b/c/d

 *     - a/b/h

 * - e

 * - f/g

 * Note that the number of elements in the path does not necessarily

 * determine the depth of the menu item in the tree.

 *

 * When responding to a page request, the menu system looks to see if the

 * path requested by the browser is registered as a menu item with a

 * callback. If not, the system searches up the menu tree for the most

 * complete match with a callback it can find. If the path a/b/i is

 * requested in the tree above, the callback for a/b would be used.

 *

 * The found callback function is called with any arguments specified

 * in the "page arguments" attribute of its menu item. The

 * attribute must be an array. After these arguments, any remaining

 * components of the path are appended as further arguments. In this

 * way, the callback for a/b above could respond to a request for

 * a/b/i differently than a request for a/b/j.

 *

 * For an illustration of this process, see page_example.module.

 *

 * Access to the callback functions is also protected by the menu system.

 * The "access callback" with an optional "access arguments" of each menu

 * item is called before the page callback proceeds. If this returns TRUE,

 * then access is granted; if FALSE, then access is denied. Default local task

 * menu items (see next paragraph) may omit this attribute to use the value

 * provided by the parent item.

 *

 * In the default Drupal interface, you will notice many links rendered as

 * tabs. These are known in the menu system as "local tasks", and they are

 * rendered as tabs by default, though other presentations are possible.

 * Local tasks function just as other menu items in most respects. It is

 * convention that the names of these tasks should be short verbs if

 * possible. In addition, a "default" local task should be provided for

 * each set. When visiting a local task's parent menu item, the default

 * local task will be rendered as if it is selected; this provides for a

 * normal tab user experience. This default task is special in that it

 * links not to its provided path, but to its parent item's path instead.

 * The default task's path is only used to place it appropriately in the

 * menu hierarchy.

 *

 * Everything described so far is stored in the menu_router table. The

 * menu_links table holds the visible menu links. By default these are

 * derived from the same hook_menu definitions, however you are free to

 * add more with menu_link_save().

 */

/**

 * @defgroup menu_flags Menu flags

 * @{

 * Flags for use in the "type" attribute of menu items.

 */

/**

 * Internal menu flag -- menu item is the root of the menu tree.

 */

define('MENU_IS_ROOT', 0x0001);

/**

 * Internal menu flag -- menu item is visible in the menu tree.

 */

define('MENU_VISIBLE_IN_TREE', 0x0002);

/**

 * Internal menu flag -- menu item is visible in the breadcrumb.

 */

define('MENU_VISIBLE_IN_BREADCRUMB', 0x0004);

/**

 * Internal menu flag -- menu item links back to its parent.

 */

define('MENU_LINKS_TO_PARENT', 0x0008);

/**

 * Internal menu flag -- menu item can be modified by administrator.

 */

define('MENU_MODIFIED_BY_ADMIN', 0x0020);

/**

 * Internal menu flag -- menu item was created by administrator.

 */

define('MENU_CREATED_BY_ADMIN', 0x0040);

/**

 * Internal menu flag -- menu item is a local task.

 */

define('MENU_IS_LOCAL_TASK', 0x0080);

/**

 * Internal menu flag -- menu item is a local action.

 */

define('MENU_IS_LOCAL_ACTION', 0x0100);

/**

 * @} End of "Menu flags".

 */

/**

 * @defgroup menu_item_types Menu item types

 * @{

 * Definitions for various menu item types.

 *

 * Menu item definitions provide one of these constants, which are shortcuts for

 * combinations of @link menu_flags Menu flags @endlink.

 */

/**

 * Menu type -- A "normal" menu item that's shown in menu and breadcrumbs.

 *

 * Normal menu items show up in the menu tree and can be moved/hidden by

 * the administrator. Use this for most menu items. It is the default value if

 * no menu item type is specified.

 */

define('MENU_NORMAL_ITEM', MENU_VISIBLE_IN_TREE | MENU_VISIBLE_IN_BREADCRUMB);

/**

 * Menu type -- A hidden, internal callback, typically used for API calls.

 *

 * Callbacks simply register a path so that the correct function is fired

 * when the URL is accessed. They do not appear in menus or breadcrumbs.

 */

define('MENU_CALLBACK', 0x0000);

/**

 * Menu type -- A normal menu item, hidden until enabled by an administrator.

 *

 * Modules may "suggest" menu items that the administrator may enable. They act

 * just as callbacks do until enabled, at which time they act like normal items.

 * Note for the value: 0x0010 was a flag which is no longer used, but this way

 * the values of MENU_CALLBACK and MENU_SUGGESTED_ITEM are separate.

 */

define('MENU_SUGGESTED_ITEM', MENU_VISIBLE_IN_BREADCRUMB | 0x0010);

/**

 * Menu type -- A task specific to the parent item, usually rendered as a tab.

 *

 * Local tasks are menu items that describe actions to be performed on their

 * parent item. An example is the path "node/52/edit", which performs the

 * "edit" task on "node/52".

 */

define('MENU_LOCAL_TASK', MENU_IS_LOCAL_TASK | MENU_VISIBLE_IN_BREADCRUMB);

/**

 * Menu type -- The "default" local task, which is initially active.

 *

 * Every set of local tasks should provide one "default" task, that links to the

 * same path as its parent when clicked.

 */

define('MENU_DEFAULT_LOCAL_TASK', MENU_IS_LOCAL_TASK | MENU_LINKS_TO_PARENT | MENU_VISIBLE_IN_BREADCRUMB);

/**

 * Menu type -- An action specific to the parent, usually rendered as a link.

 *

 * Local actions are menu items that describe actions on the parent item such

 * as adding a new user, taxonomy term, etc.

 */

define('MENU_LOCAL_ACTION', MENU_IS_LOCAL_TASK | MENU_IS_LOCAL_ACTION | MENU_VISIBLE_IN_BREADCRUMB);

/**

 * @} End of "Menu item types".

 */

/**

 * @defgroup menu_context_types Menu context types

 * @{

 * Flags for use in the "context" attribute of menu router items.

 */

/**

 * Internal menu flag: Invisible local task.

 *

 * This flag may be used for local tasks like "Delete", so custom modules and

 * themes can alter the default context and expose the task by altering menu.

 */

define('MENU_CONTEXT_NONE', 0x0000);

/**

 * Internal menu flag: Local task should be displayed in page context.

 */

define('MENU_CONTEXT_PAGE', 0x0001);

/**

 * Internal menu flag: Local task should be displayed inline.

 */

define('MENU_CONTEXT_INLINE', 0x0002);

/**

 * @} End of "Menu context types".

 */

/**

 * @defgroup menu_status_codes Menu status codes

 * @{

 * Status codes for menu callbacks.

 */

/**

 * Internal menu status code -- Menu item was found.

 */

define('MENU_FOUND', 1);

/**

 * Internal menu status code -- Menu item was not found.

 */

define('MENU_NOT_FOUND', 2);

/**

 * Internal menu status code -- Menu item access is denied.

 */

define('MENU_ACCESS_DENIED', 3);

/**

 * Internal menu status code -- Menu item inaccessible because site is offline.

 */

define('MENU_SITE_OFFLINE', 4);

/**

 * Internal menu status code -- Everything is working fine.

 */

define('MENU_SITE_ONLINE', 5);

/**

 * @} End of "Menu status codes".

 */

/**

 * @defgroup menu_tree_parameters Menu tree parameters

 * @{

 * Parameters for a menu tree.

 */

 /**

 * The maximum number of path elements for a menu callback

 */

define('MENU_MAX_PARTS', 9);

/**

 * The maximum depth of a menu links tree - matches the number of p columns.

 */

define('MENU_MAX_DEPTH', 9);

/**

 * @} End of "Menu tree parameters".

 */

/**

 * Reserved key to identify the most specific menu link for a given path.

 *

 * The value of this constant is a hash of the constant name. We use the hash

 * so that the reserved key is over 32 characters in length and will not

 * collide with allowed menu names:

 * @code

 * sha1('MENU_PREFERRED_LINK') = 1cf698d64d1aa4b83907cf6ed55db3a7f8e92c91

 * @endcode

 *

 * @see menu_link_get_preferred()

 */

define('MENU_PREFERRED_LINK', '1cf698d64d1aa4b83907cf6ed55db3a7f8e92c91');

/**

 * Returns the ancestors (and relevant placeholders) for any given path.

 *

 * For example, the ancestors of node/12345/edit are:

 * - node/12345/edit

 * - node/12345/%

 * - node/%/edit

 * - node/%/%

 * - node/12345

 * - node/%

 * - node

 *

 * To generate these, we will use binary numbers. Each bit represents a

 * part of the path. If the bit is 1, then it represents the original

 * value while 0 means wildcard. If the path is node/12/edit/foo

 * then the 1011 bitstring represents node/%/edit/foo where % means that

 * any argument matches that part. We limit ourselves to using binary

 * numbers that correspond the patterns of wildcards of router items that

 * actually exists. This list of 'masks' is built in menu_rebuild().

 *

 * @param $parts

 *   An array of path parts; for the above example, 

 *   array('node', '12345', 'edit').

 *

 * @return

 *   An array which contains the ancestors and placeholders. Placeholders

 *   simply contain as many '%s' as the ancestors.

 */

function menu_get_ancestors($parts) {

  $number_parts = count($parts);

  $ancestors = array();

  $length =  $number_parts - 1;

  $end = (1 << $number_parts) - 1;

  $masks = variable_get('menu_masks');

  // If the optimized menu_masks array is not available use brute force to get

  // the correct $ancestors and $placeholders returned. Do not use this as the

  // default value of the menu_masks variable to avoid building such a big

  // array.

  if (!$masks) {

    $masks = range(511, 1);

  }

  // Only examine patterns that actually exist as router items (the masks).

  foreach ($masks as $i) {

    if ($i > $end) {

      // Only look at masks that are not longer than the path of interest.

      continue;

    }

    elseif ($i < (1 << $length)) {

      // We have exhausted the masks of a given length, so decrease the length.

      --$length;

    }

    $current = '';

    for ($j = $length; $j >= 0; $j--) {

      // Check the bit on the $j offset.

      if ($i & (1 << $j)) {

        // Bit one means the original value.

        $current .= $parts[$length - $j];

      }

      else {

        // Bit zero means means wildcard.

        $current .= '%';

      }

      // Unless we are at offset 0, add a slash.

      if ($j) {

        $current .= '/';

      }

    }

    $ancestors[] = $current;

  }

  return $ancestors;

}

/**

 * Unserializes menu data, using a map to replace path elements.

 *

 * The menu system stores various path-related information (such as the 'page

 * arguments' and 'access arguments' components of a menu item) in the database

 * using serialized arrays, where integer values in the arrays represent

 * arguments to be replaced by values from the path. This function first

 * unserializes such menu information arrays, and then does the path

 * replacement.

 *

 * The path replacement acts on each integer-valued element of the unserialized

 * menu data array ($data) using a map array ($map, which is typically an array

 * of path arguments) as a list of replacements. For instance, if there is an

 * element of $data whose value is the number 2, then it is replaced in $data

 * with $map[2]; non-integer values in $data are left alone.

 *

 * As an example, an unserialized $data array with elements ('node_load', 1)

 * represents instructions for calling the node_load() function. Specifically,

 * this instruction says to use the path component at index 1 as the input

 * parameter to node_load(). If the path is 'node/123', then $map will be the

 * array ('node', 123), and the returned array from this function will have

 * elements ('node_load', 123), since $map[1] is 123. This return value will

 * indicate specifically that node_load(123) is to be called to load the node

 * whose ID is 123 for this menu item.

 *

 * @param $data

 *   A serialized array of menu data, as read from the database.

 * @param $map

 *   A path argument array, used to replace integer values in $data; an integer

 *   value N in $data will be replaced by value $map[N]. Typically, the $map

 *   array is generated from a call to the arg() function.

 *

 * @return

 *   The unserialized $data array, with path arguments replaced.

 */

function menu_unserialize($data, $map) {

  if ($data = unserialize($data)) {

    foreach ($data as $k => $v) {

      if (is_int($v)) {

        $data[$k] = isset($map[$v]) ? $map[$v] : '';

      }

    }

    return $data;

  }

  else {

    return array();

  }

}

/**

 * Replaces the statically cached item for a given path.

 *

 * @param $path

 *   The path.

 * @param $router_item

 *   The router item. Usually a router entry from menu_get_item() is either

 *   modified or set to a different path. This allows the navigation block,

 *   the page title, the breadcrumb, and the page help to be modified in one

 *   call.

 */

function menu_set_item($path, $router_item) {

  menu_get_item($path, $router_item);

}

/**

 * Gets a router item.

 *

 * @param $path

 *   The path; for example, 'node/5'. The function will find the corresponding

 *   node/% item and return that.

 * @param $router_item

 *   Internal use only.

 *

 * @return

 *   The router item or, if an error occurs in _menu_translate(), FALSE. A

 *   router item is an associative array corresponding to one row in the

 *   menu_router table. The value corresponding to the key 'map' holds the

 *   loaded objects. The value corresponding to the key 'access' is TRUE if the

 *   current user can access this page. The values corresponding to the keys

 *   'title', 'page_arguments', 'access_arguments', and 'theme_arguments' will

 *   be filled in based on the database values and the objects loaded.

 */

function menu_get_item($path = NULL, $router_item = NULL) {

  $router_items = &drupal_static(__FUNCTION__);

  if (!isset($path)) {

    $path = $_GET['q'];

  }

  if (isset($router_item)) {

    $router_items[$path] = $router_item;

  }

  if (!isset($router_items[$path])) {

    // Rebuild if we know it's needed, or if the menu masks are missing which

    // occurs rarely, likely due to a race condition of multiple rebuilds.

    if (variable_get('menu_rebuild_needed', FALSE) || !variable_get('menu_masks', array())) {

      if (_menu_check_rebuild()) {

        menu_rebuild();

      }

    }

    $original_map = arg(NULL, $path);

    $parts = array_slice($original_map, 0, MENU_MAX_PARTS);

    $ancestors = menu_get_ancestors($parts);

    $router_item = db_query_range('SELECT * FROM {menu_router} WHERE path IN (:ancestors) ORDER BY fit DESC', 0, 1, array(':ancestors' => $ancestors))->fetchAssoc();

    if ($router_item) {

      // Allow modules to alter the router item before it is translated and

      // checked for access.

      drupal_alter('menu_get_item', $router_item, $path, $original_map);

      $map = _menu_translate($router_item, $original_map);

      $router_item['original_map'] = $original_map;

      if ($map === FALSE) {

        $router_items[$path] = FALSE;

        return FALSE;

      }

      if ($router_item['access']) {

        $router_item['map'] = $map;

        $router_item['page_arguments'] = array_merge(menu_unserialize($router_item['page_arguments'], $map), array_slice($map, $router_item['number_parts']));

        $router_item['theme_arguments'] = array_merge(menu_unserialize($router_item['theme_arguments'], $map), array_slice($map, $router_item['number_parts']));

      }

    }

    $router_items[$path] = $router_item;

  }

  return $router_items[$path];

}

/**

 * Execute the page callback associated with the current path.

 *

 * @param $path

 *   The drupal path whose handler is to be be executed. If set to NULL, then

 *   the current path is used.

 * @param $deliver

 *   (optional) A boolean to indicate whether the content should be sent to the

 *   browser using the appropriate delivery callback (TRUE) or whether to return

 *   the result to the caller (FALSE).

 */

function menu_execute_active_handler($path = NULL, $deliver = TRUE) {

  // Check if site is offline.

  $page_callback_result = _menu_site_is_offline() ? MENU_SITE_OFFLINE : MENU_SITE_ONLINE;

  // Allow other modules to change the site status but not the path because that

  // would not change the global variable. hook_url_inbound_alter() can be used

  // to change the path. Code later will not use the $read_only_path variable.

  $read_only_path = !empty($path) ? $path : $_GET['q'];

  drupal_alter('menu_site_status', $page_callback_result, $read_only_path);

  // Only continue if the site status is not set.

  if ($page_callback_result == MENU_SITE_ONLINE) {

    if ($router_item = menu_get_item($path)) {

      if ($router_item['access']) {

        if ($router_item['include_file']) {

          require_once DRUPAL_ROOT . '/' . $router_item['include_file'];

        }

        $page_callback_result = call_user_func_array($router_item['page_callback'], $router_item['page_arguments']);

      }

      else {

        $page_callback_result = MENU_ACCESS_DENIED;

      }

    }

    else {

      $page_callback_result = MENU_NOT_FOUND;

    }

  }

  // Deliver the result of the page callback to the browser, or if requested,

  // return it raw, so calling code can do more processing.

  if ($deliver) {

    $default_delivery_callback = (isset($router_item) && $router_item) ? $router_item['delivery_callback'] : NULL;

    drupal_deliver_page($page_callback_result, $default_delivery_callback);

  }

  else {

    return $page_callback_result;

  }

}

/**

 * Loads objects into the map as defined in the $item['load_functions'].

 *

 * @param $item

 *   A menu router or menu link item

 * @param $map

 *   An array of path arguments; for example, array('node', '5').

 *

 * @return

 *   Returns TRUE for success, FALSE if an object cannot be loaded.

 *   Names of object loading functions are placed in $item['load_functions'].

 *   Loaded objects are placed in $map[]; keys are the same as keys in the

 *   $item['load_functions'] array.

 *   $item['access'] is set to FALSE if an object cannot be loaded.

 */

function _menu_load_objects(&$item, &$map) {

  if ($load_functions = $item['load_functions']) {

    // If someone calls this function twice, then unserialize will fail.

    if (!is_array($load_functions)) {

      $load_functions = unserialize($load_functions);

    }

    $path_map = $map;

    foreach ($load_functions as $index => $function) {

      if ($function) {

        $value = isset($path_map[$index]) ? $path_map[$index] : '';

        if (is_array($function)) {

          // Set up arguments for the load function. These were pulled from

          // 'load arguments' in the hook_menu() entry, but they need

          // some processing. In this case the $function is the key to the

          // load_function array, and the value is the list of arguments.

          list($function, $args) = each($function);

          $load_functions[$index] = $function;

          // Some arguments are placeholders for dynamic items to process.

          foreach ($args as $i => $arg) {

            if ($arg === '%index') {

              // Pass on argument index to the load function, so multiple

              // occurrences of the same placeholder can be identified.

              $args[$i] = $index;

            }

            if ($arg === '%map') {

              // Pass on menu map by reference. The accepting function must

              // also declare this as a reference if it wants to modify

              // the map.

              $args[$i] = &$map;

            }

            if (is_int($arg)) {

              $args[$i] = isset($path_map[$arg]) ? $path_map[$arg] : '';

            }

          }

          array_unshift($args, $value);

          $return = call_user_func_array($function, $args);

        }

        else {

          $return = $function($value);

        }

        // If callback returned an error or there is no callback, trigger 404.

        if ($return === FALSE) {

          $item['access'] = FALSE;

          $map = FALSE;

          return FALSE;

        }

        $map[$index] = $return;

      }

    }

    $item['load_functions'] = $load_functions;

  }

  return TRUE;

}

/**

 * Checks access to a menu item using the access callback.

 *

 * @param $item

 *   A menu router or menu link item

 * @param $map

 *   An array of path arguments; for example, array('node', '5').

 *

 * @return

 *   $item['access'] becomes TRUE if the item is accessible, FALSE otherwise.

 */

function _menu_check_access(&$item, $map) {

  $item['access'] = FALSE;

  // Determine access callback, which will decide whether or not the current

  // user has access to this path.

  $callback = empty($item['access_callback']) ? 0 : trim($item['access_callback']);

  // Check for a TRUE or FALSE value.

  if (is_numeric($callback)) {

    $item['access'] = (bool) $callback;

  }

  else {

    $arguments = menu_unserialize($item['access_arguments'], $map);

    // As call_user_func_array is quite slow and user_access is a very common

    // callback, it is worth making a special case for it.

    if ($callback == 'user_access') {

      $item['access'] = (count($arguments) == 1) ? user_access($arguments[0]) : user_access($arguments[0], $arguments[1]);

    }

    elseif (function_exists($callback)) {

      $item['access'] = call_user_func_array($callback, $arguments);

    }

  }

}

/**

 * Localizes the router item title using t() or another callback.

 *

 * Translate the title and description to allow storage of English title

 * strings in the database, yet display of them in the language required

 * by the current user.

 *

 * @param $item

 *   A menu router item or a menu link item.

 * @param $map

 *   The path as an array with objects already replaced. E.g., for path

 *   node/123 $map would be array('node', $node) where $node is the node

 *   object for node 123.

 * @param $link_translate

 *   TRUE if we are translating a menu link item; FALSE if we are

 *   translating a menu router item.

 *

 * @return

 *   No return value.

 *   $item['title'] is localized according to $item['title_callback'].

 *   If an item's callback is check_plain(), $item['options']['html'] becomes

 *   TRUE.

 *   $item['description'] is translated using t().

 *   When doing link translation and the $item['options']['attributes']['title']

 *   (link title attribute) matches the description, it is translated as well.

 */

function _menu_item_localize(&$item, $map, $link_translate = FALSE) {

  $callback = $item['title_callback'];

  $item['localized_options'] = $item['options'];

  // All 'class' attributes are assumed to be an array during rendering, but

  // links stored in the database may use an old string value.

  // @todo In order to remove this code we need to implement a database update

  //   including unserializing all existing link options and running this code

  //   on them, as well as adding validation to menu_link_save().

  if (isset($item['options']['attributes']['class']) && is_string($item['options']['attributes']['class'])) {

    $item['localized_options']['attributes']['class'] = explode(' ', $item['options']['attributes']['class']);

  }

  // If we are translating the title of a menu link, and its title is the same

  // as the corresponding router item, then we can use the title information

  // from the router. If it's customized, then we need to use the link title

  // itself; can't localize.

  // If we are translating a router item (tabs, page, breadcrumb), then we

  // can always use the information from the router item.

  if (!$link_translate || ($item['title'] == $item['link_title'])) {

    // t() is a special case. Since it is used very close to all the time,

    // we handle it directly instead of using indirect, slower methods.

    if ($callback == 't') {

      if (empty($item['title_arguments'])) {

        $item['title'] = t($item['title']);

      }

      else {

        $item['title'] = t($item['title'], menu_unserialize($item['title_arguments'], $map));

      }

    }

    elseif ($callback && function_exists($callback)) {

      if (empty($item['title_arguments'])) {

        $item['title'] = $callback($item['title']);

      }

      else {

        $item['title'] = call_user_func_array($callback, menu_unserialize($item['title_arguments'], $map));

      }

      // Avoid calling check_plain again on l() function.

      if ($callback == 'check_plain') {

        $item['localized_options']['html'] = TRUE;

      }

    }

  }

  elseif ($link_translate) {

    $item['title'] = $item['link_title'];

  }

  // Translate description, see the motivation above.

  if (!empty($item['description'])) {

    $original_description = $item['description'];

    $item['description'] = t($item['description']);

    if ($link_translate && isset($item['options']['attributes']['title']) && $item['options']['attributes']['title'] == $original_description) {

      $item['localized_options']['attributes']['title'] = $item['description'];

    }

  }

}

/**

 * Handles dynamic path translation and menu access control.

 *

 * When a user arrives on a page such as node/5, this function determines

 * what "5" corresponds to, by inspecting the page's menu path definition,

 * node/%node. This will call node_load(5) to load the corresponding node

 * object.

 *

 * It also works in reverse, to allow the display of tabs and menu items which

 * contain these dynamic arguments, translating node/%node to node/5.

 *

 * Translation of menu item titles and descriptions are done here to

 * allow for storage of English strings in the database, and translation

 * to the language required to generate the current page.

 *

 * @param $router_item

 *   A menu router item

 * @param $map

 *   An array of path arguments; for example, array('node', '5').

 * @param $to_arg

 *   Execute $item['to_arg_functions'] or not. Use only if you want to render a

 *   path from the menu table, for example tabs.

 *

 * @return

 *   Returns the map with objects loaded as defined in the

 *   $item['load_functions']. $item['access'] becomes TRUE if the item is

 *   accessible, FALSE otherwise. $item['href'] is set according to the map.

 *   If an error occurs during calling the load_functions (like trying to load

 *   a non-existent node) then this function returns FALSE.

 */

function _menu_translate(&$router_item, $map, $to_arg = FALSE) {

  if ($to_arg && !empty($router_item['to_arg_functions'])) {

    // Fill in missing path elements, such as the current uid.

    _menu_link_map_translate($map, $router_item['to_arg_functions']);

  }

  // The $path_map saves the pieces of the path as strings, while elements in

  // $map may be replaced with loaded objects.

  $path_map = $map;

  if (!empty($router_item['load_functions']) && !_menu_load_objects($router_item, $map)) {

    // An error occurred loading an object.

    $router_item['access'] = FALSE;

    return FALSE;

  }

  // Generate the link path for the page request or local tasks.

  $link_map = explode('/', $router_item['path']);

  if (isset($router_item['tab_root'])) {

    $tab_root_map = explode('/', $router_item['tab_root']);

  }

  if (isset($router_item['tab_parent'])) {

    $tab_parent_map = explode('/', $router_item['tab_parent']);

  }

  for ($i = 0; $i < $router_item['number_parts']; $i++) {

    if ($link_map[$i] == '%') {

      $link_map[$i] = $path_map[$i];

    }

    if (isset($tab_root_map[$i]) && $tab_root_map[$i] == '%') {

      $tab_root_map[$i] = $path_map[$i];

    }

    if (isset($tab_parent_map[$i]) && $tab_parent_map[$i] == '%') {

      $tab_parent_map[$i] = $path_map[$i];

    }

  }

  $router_item['href'] = implode('/', $link_map);

  $router_item['tab_root_href'] = implode('/', $tab_root_map);

  $router_item['tab_parent_href'] = implode('/', $tab_parent_map);

  $router_item['options'] = array();

  _menu_check_access($router_item, $map);

  // For performance, don't localize an item the user can't access.

  if ($router_item['access']) {

    _menu_item_localize($router_item, $map);

  }

  return $map;

}

/**

 * Translates the path elements in the map using any to_arg helper function.

 *

 * @param $map

 *   An array of path arguments; for example, array('node', '5').

 * @param $to_arg_functions

 *   An array of helper functions; for example, array(2 => 'menu_tail_to_arg').

 *

 * @see hook_menu()

 */

function _menu_link_map_translate(&$map, $to_arg_functions) {

  $to_arg_functions = unserialize($to_arg_functions);

  foreach ($to_arg_functions as $index => $function) {

    // Translate place-holders into real values.

    $arg = $function(!empty($map[$index]) ? $map[$index] : '', $map, $index);

    if (!empty($map[$index]) || isset($arg)) {

      $map[$index] = $arg;

    }

    else {

      unset($map[$index]);

    }

  }

}

/**

 * Returns a string containing the path relative to the current index.

 */

function menu_tail_to_arg($arg, $map, $index) {

  return implode('/', array_slice($map, $index));

}

/**

 * Loads the path as one string relative to the current index.

 *

 * To use this load function, you must specify the load arguments

 * in the router item as:

 * @code

 * $item['load arguments'] = array('%map', '%index');

 * @endcode

 *

 * @see search_menu().

 */

function menu_tail_load($arg, &$map, $index) {

  $arg = implode('/', array_slice($map, $index));

  $map = array_slice($map, 0, $index);

  return $arg;

}

/**

 * Provides menu link access control, translation, and argument handling.

 *

 * This function is similar to _menu_translate(), but it also does

 * link-specific preparation (such as always calling to_arg() functions).

 *

 * @param $item

 *   A menu link.

 * @param $translate

 *   (optional) Whether to try to translate a link containing dynamic path

 *   argument placeholders (%) based on the menu router item of the current

 *   path. Defaults to FALSE. Internally used for breadcrumbs.

 *

 * @return

 *   Returns the map of path arguments with objects loaded as defined in the

 *   $item['load_functions'].

 *   $item['access'] becomes TRUE if the item is accessible, FALSE otherwise.

 *   $item['href'] is generated from link_path, possibly by to_arg functions.

 *   $item['title'] is generated from link_title, and may be localized.

 *   $item['options'] is unserialized; it is also changed within the call here

 *   to $item['localized_options'] by _menu_item_localize().

 */

function _menu_link_translate(&$item, $translate = FALSE) {

  if (!is_array($item['options'])) {

    $item['options'] = unserialize($item['options']);

  }

  if ($item['external']) {

    $item['access'] = 1;

    $map = array();

    $item['href'] = $item['link_path'];

    $item['title'] = $item['link_title'];

    $item['localized_options'] = $item['options'];

  }

  else {

    // Complete the path of the menu link with elements from the current path,

    // if it contains dynamic placeholders (%).

    $map = explode('/', $item['link_path']);

    if (strpos($item['link_path'], '%') !== FALSE) {

      // Invoke registered to_arg callbacks.

      if (!empty($item['to_arg_functions'])) {

        _menu_link_map_translate($map, $item['to_arg_functions']);

      }

      // Or try to derive the path argument map from the current router item,

      // if this $item's path is within the router item's path. This means

      // that if we are on the current path 'foo/%/bar/%/baz', then

      // menu_get_item() will have translated the menu router item for the

      // current path, and we can take over the argument map for a link like

      // 'foo/%/bar'. This inheritance is only valid for breadcrumb links.

      // @see _menu_tree_check_access()

      // @see menu_get_active_breadcrumb()

      elseif ($translate && ($current_router_item = menu_get_item())) {

        // If $translate is TRUE, then this link is in the active trail.

        // Only translate paths within the current path.

        if (strpos($current_router_item['path'], $item['link_path']) === 0) {

          $count = count($map);

          $map = array_slice($current_router_item['original_map'], 0, $count);

          $item['original_map'] = $map;

          if (isset($current_router_item['map'])) {

            $item['map'] = array_slice($current_router_item['map'], 0, $count);

          }

          // Reset access to check it (for the first time).

          unset($item['access']);

        }

      }

    }

    $item['href'] = implode('/', $map);

    // Skip links containing untranslated arguments.

    if (strpos($item['href'], '%') !== FALSE) {

      $item['access'] = FALSE;

      return FALSE;

    }

    // menu_tree_check_access() may set this ahead of time for links to nodes.

    if (!isset($item['access'])) {

      if (!empty($item['load_functions']) && !_menu_load_objects($item, $map)) {

        // An error occurred loading an object.

        $item['access'] = FALSE;

        return FALSE;

      }

      _menu_check_access($item, $map);

    }

    // For performance, don't localize a link the user can't access.

    if ($item['access']) {

      _menu_item_localize($item, $map, TRUE);

    }

  }

  // Allow other customizations - e.g. adding a page-specific query string to the

  // options array. For performance reasons we only invoke this hook if the link

  // has the 'alter' flag set in the options array.

  if (!empty($item['options']['alter'])) {

    drupal_alter('translated_menu_link', $item, $map);

  }

  return $map;

}

/**

 * Gets a loaded object from a router item.

 *

 * menu_get_object() provides access to objects loaded by the current router

 * item. For example, on the page node/%node, the router loads the %node object,

 * and calling menu_get_object() will return that. Normally, it is necessary to

 * specify the type of object referenced, however node is the default.

 * The following example tests to see whether the node being displayed is of the

 * "story" content type:

 * @code

 * $node = menu_get_object();

 * $story = $node->type == 'story';

 * @endcode

 *

 * @param $type

 *   Type of the object. These appear in hook_menu definitions as %type. Core

 *   provides aggregator_feed, aggregator_category, contact, filter_format,

 *   forum_term, menu, menu_link, node, taxonomy_vocabulary, user. See the

 *   relevant {$type}_load function for more on each. Defaults to node.

 * @param $position

 *   The position of the object in the path, where the first path segment is 0.

 *   For node/%node, the position of %node is 1, but for comment/reply/%node,

 *   it's 2. Defaults to 1.

 * @param $path

 *   See menu_get_item() for more on this. Defaults to the current path.

 */

function menu_get_object($type = 'node', $position = 1, $path = NULL) {

  $router_item = menu_get_item($path);

  if (isset($router_item['load_functions'][$position]) && !empty($router_item['map'][$position]) && $router_item['load_functions'][$position] == $type . '_load') {

    return $router_item['map'][$position];

  }

}

/**

 * Renders a menu tree based on the current path.

 *

 * The tree is expanded based on the current path and dynamic paths are also

 * changed according to the defined to_arg functions (for example the 'My

 * account' link is changed from user/% to a link with the current user's uid).

 *

 * @param $menu_name

 *   The name of the menu.

 *

 * @return

 *   A structured array representing the specified menu on the current page, to

 *   be rendered by drupal_render().

 */

function menu_tree($menu_name) {

  $menu_output = &drupal_static(__FUNCTION__, array());

  if (!isset($menu_output[$menu_name])) {

    $tree = menu_tree_page_data($menu_name);

    $menu_output[$menu_name] = menu_tree_output($tree);

  }

  return $menu_output[$menu_name];

}

/**

 * Returns an output structure for rendering a menu tree.

 *

 * The menu item's LI element is given one of the following classes:

 * - expanded: The menu item is showing its submenu.

 * - collapsed: The menu item has a submenu which is not shown.

 * - leaf: The menu item has no submenu.

 *

 * @param $tree

 *   A data structure representing the tree as returned from menu_tree_data.

 *

 * @return

 *   A structured array to be rendered by drupal_render().

 */

function menu_tree_output($tree) {

  $build = array();

  $items = array();

  // Pull out just the menu links we are going to render so that we

  // get an accurate count for the first/last classes.

  foreach ($tree as $data) {

    if ($data['link']['access'] && !$data['link']['hidden']) {

      $items[] = $data;

    }

  }

  $router_item = menu_get_item();

  $num_items = count($items);

  foreach ($items as $i => $data) {

    $class = array();

    if ($i == 0) {

      $class[] = 'first';

    }

    if ($i == $num_items - 1) {

      $class[] = 'last';

    }

    // Set a class for the <li>-tag. Since $data['below'] may contain local

    // tasks, only set 'expanded' class if the link also has children within

    // the current menu.

    if ($data['link']['has_children'] && $data['below']) {

      $class[] = 'expanded';

    }

    elseif ($data['link']['has_children']) {

      $class[] = 'collapsed';

    }

    else {

      $class[] = 'leaf';

    }

    // Set a class if the link is in the active trail.

    if ($data['link']['in_active_trail']) {

      $class[] = 'active-trail';

      $data['link']['localized_options']['attributes']['class'][] = 'active-trail';

    }

    // Normally, l() compares the href of every link with $_GET['q'] and sets

    // the active class accordingly. But local tasks do not appear in menu

    // trees, so if the current path is a local task, and this link is its

    // tab root, then we have to set the class manually.

    if ($data['link']['href'] == $router_item['tab_root_href'] && $data['link']['href'] != $_GET['q']) {

      $data['link']['localized_options']['attributes']['class'][] = 'active';

    }

    // Allow menu-specific theme overrides.

    $element['#theme'] = 'menu_link__' . strtr($data['link']['menu_name'], '-', '_');

    $element['#attributes']['class'] = $class;

    $element['#title'] = $data['link']['title'];

    $element['#href'] = $data['link']['href'];

    $element['#localized_options'] = !empty($data['link']['localized_options']) ? $data['link']['localized_options'] : array();

    $element['#below'] = $data['below'] ? menu_tree_output($data['below']) : $data['below'];

    $element['#original_link'] = $data['link'];

    // Index using the link's unique mlid.

    $build[$data['link']['mlid']] = $element;

  }

  if ($build) {

    // Make sure drupal_render() does not re-order the links.

    $build['#sorted'] = TRUE;

    // Add the theme wrapper for outer markup.

    // Allow menu-specific theme overrides.

    $build['#theme_wrappers'][] = 'menu_tree__' . strtr($data['link']['menu_name'], '-', '_');

  }

  return $build;

}

/**

 * Gets the data structure representing a named menu tree.

 *

 * Since this can be the full tree including hidden items, the data returned

 * may be used for generating an an admin interface or a select.

 *

 * @param $menu_name

 *   The named menu links to return

 * @param $link

 *   A fully loaded menu link, or NULL. If a link is supplied, only the

 *   path to root will be included in the returned tree - as if this link

 *   represented the current page in a visible menu.

 * @param $max_depth

 *   Optional maximum depth of links to retrieve. Typically useful if only one

 *   or two levels of a sub tree are needed in conjunction with a non-NULL

 *   $link, in which case $max_depth should be greater than $link['depth'].

 *

 * @return

 *   An tree of menu links in an array, in the order they should be rendered.

 */

function menu_tree_all_data($menu_name, $link = NULL, $max_depth = NULL) {

  $tree = &drupal_static(__FUNCTION__, array());

  // Use $mlid as a flag for whether the data being loaded is for the whole tree.

  $mlid = isset($link['mlid']) ? $link['mlid'] : 0;

  // Generate a cache ID (cid) specific for this $menu_name, $link, $language, and depth.

  $cid = 'links:' . $menu_name . ':all:' . $mlid . ':' . $GLOBALS['language']->language . ':' . (int) $max_depth;

  if (!isset($tree[$cid])) {

    // If the static variable doesn't have the data, check {cache_menu}.

    $cache = cache_get($cid, 'cache_menu');

    if ($cache && isset($cache->data)) {

      // If the cache entry exists, it contains the parameters for

      // menu_build_tree().

      $tree_parameters = $cache->data;

    }

    // If the tree data was not in the cache, build $tree_parameters.

    if (!isset($tree_parameters)) {