Menu system

  1. 7 core/includes/menu.inc menu
  2. 6 core/includes/menu.inc menu

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().

File

core/includes/menu.inc, line 8
API for the Drupal menu system.

Functions

Namesort descending Location Description
drupal_help_arg core/includes/menu.inc Generates elements for the $arg array in the help hook.
menu_build_tree core/includes/menu.inc Builds a menu tree, translates links, and checks access.
menu_cache_clear core/includes/menu.inc Clears the cached cached data for a single named menu.
menu_cache_clear_all core/includes/menu.inc Clears all cached menu data.
menu_contextual_links core/includes/menu.inc Retrieves contextual links for a path based on registered local tasks.
menu_delete_links core/includes/menu.inc Deletes all links for a menu.
menu_execute_active_handler core/includes/menu.inc Execute the page callback associated with the current path.
menu_get_active_breadcrumb core/includes/menu.inc Gets the breadcrumb for the current page, as determined by the active trail.
menu_get_active_help core/includes/menu.inc Returns the help associated with the active menu item.
menu_get_active_menu_names core/includes/menu.inc Gets the active menu for the current page.
menu_get_active_title core/includes/menu.inc Gets the title of the current page, as determined by the active trail.
menu_get_active_trail core/includes/menu.inc Gets the active trail (path to root menu root) of the current page.
menu_get_ancestors core/includes/menu.inc Returns the ancestors (and relevant placeholders) for any given path.
menu_get_custom_theme core/includes/menu.inc Gets the custom theme for the current page, if there is one.
menu_get_item core/includes/menu.inc Gets a router item.
menu_get_names core/includes/menu.inc Build a list of named menus.
menu_get_object core/includes/menu.inc Gets a loaded object from a router item.
menu_get_router core/includes/menu.inc Gets the menu router.
menu_links_clone core/includes/menu.inc Clones an array of menu links.
menu_link_children_relative_depth core/includes/menu.inc Finds the depth of an item's children relative to its depth.
menu_link_delete core/includes/menu.inc Delete one or several menu links.
menu_link_get_preferred core/includes/menu.inc Looks up the preferred menu link for a given system path.
menu_link_load core/includes/menu.inc Gets a translated, access-checked menu link that is ready for rendering.
menu_link_maintain core/includes/menu.inc Inserts, updates, or deletes an uncustomized menu link related to a module.
menu_link_save core/includes/menu.inc Saves a menu link.
menu_list_system_menus core/includes/menu.inc Returns an array containing the names of system-defined (default) menus.
menu_load_links core/includes/menu.inc Returns an array containing all links for a menu.
menu_local_actions core/includes/menu.inc Returns the rendered local actions at the current level.
menu_local_tabs core/includes/menu.inc Returns a renderable element for the primary and secondary tabs.
menu_local_tasks core/includes/menu.inc Collects the local tasks (tabs), action links, and the root path.
menu_main_menu core/includes/menu.inc Returns an array of links to be rendered as the Main menu.
menu_navigation_links core/includes/menu.inc Returns an array of links for a navigation menu.
menu_primary_local_tasks core/includes/menu.inc Returns the rendered local tasks at the top level.
menu_rebuild core/includes/menu.inc Populates the database tables used by various menu functions.
menu_reset_static_cache core/includes/menu.inc Resets the menu system static cache.
menu_router_build core/includes/menu.inc Collects and alters the menu definitions.
menu_secondary_local_tasks core/includes/menu.inc Returns the rendered local tasks at the second level.
menu_secondary_menu core/includes/menu.inc Returns an array of links to be rendered as the Secondary links.
menu_set_active_item core/includes/menu.inc Sets the active path, which determines which page is loaded.
menu_set_active_menu_names core/includes/menu.inc Sets (or gets) the active menu for the current page.
menu_set_active_trail core/includes/menu.inc Sets the active trail (path to the menu tree root) of the current page.
menu_set_custom_theme core/includes/menu.inc Sets a custom theme for the current page, if there is one.
menu_set_item core/includes/menu.inc Replaces the statically cached item for a given path.
menu_tab_root_path core/includes/menu.inc Returns the router path, or the path for a default local task's parent.
menu_tail_load core/includes/menu.inc Loads the path as one string relative to the current index.
menu_tail_to_arg core/includes/menu.inc Returns a string containing the path relative to the current index.
menu_tree core/includes/menu.inc Renders a menu tree based on the current path.
menu_tree_all_data core/includes/menu.inc Gets the data structure representing a named menu tree.
menu_tree_check_access core/includes/menu.inc Checks access and performs dynamic operations for each link in the tree.
menu_tree_collect_node_links core/includes/menu.inc Collects node links from a given menu tree recursively.
menu_tree_data core/includes/menu.inc Sorts and returns the built data representing a menu tree.
menu_tree_get_path core/includes/menu.inc Gets the path for determining the active trail of the specified menu tree.
menu_tree_output core/includes/menu.inc Returns an output structure for rendering a menu tree.
menu_tree_page_data core/includes/menu.inc Gets the data structure for a named menu tree, based on the current page.
menu_tree_set_path core/includes/menu.inc Sets the path for determining the active trail of the specified menu tree.
menu_unserialize core/includes/menu.inc Unserializes menu data, using a map to replace path elements.
template_preprocess_menu_tree core/includes/menu.inc Implements template_preprocess_HOOK() for theme_menu_tree().
theme_menu_link core/includes/menu.inc Returns HTML for a menu link and submenu.
theme_menu_local_action core/includes/menu.inc Returns HTML for a single local action link.
theme_menu_local_task core/includes/menu.inc Returns HTML for a single local task link.
theme_menu_local_tasks core/includes/menu.inc Returns HTML for primary and secondary local tasks.
theme_menu_tree core/includes/menu.inc Returns HTML for a wrapper for a menu sub-tree.
_menu_build_tree core/includes/menu.inc Builds a menu tree.
_menu_check_access core/includes/menu.inc Checks access to a menu item using the access callback.
_menu_check_rebuild core/includes/menu.inc Checks whether a menu_rebuild() is necessary.
_menu_clear_page_cache core/includes/menu.inc Clears the page and block caches at most twice per page load.
_menu_delete_item core/includes/menu.inc Deletes a single menu link.
_menu_find_router_path core/includes/menu.inc Finds the router path which will serve this path.
_menu_item_localize core/includes/menu.inc Localizes the router item title using t() or another callback.
_menu_link_build core/includes/menu.inc Builds a link from a router item.
_menu_link_find_parent core/includes/menu.inc Finds a possible parent for a given menu link.
_menu_link_map_translate core/includes/menu.inc Translates the path elements in the map using any to_arg helper function.
_menu_link_move_children core/includes/menu.inc Updates the children of a menu link that is being moved.
_menu_link_parents_set core/includes/menu.inc Sets the p1 through p9 values for a menu link being saved.
_menu_link_translate core/includes/menu.inc Provides menu link access control, translation, and argument handling.
_menu_load_objects core/includes/menu.inc Loads objects into the map as defined in the $item['load_functions'].
_menu_navigation_links_rebuild core/includes/menu.inc Builds menu links for the items in the menu router.
_menu_router_build core/includes/menu.inc Builds the router table based on the data from hook_menu().
_menu_router_cache core/includes/menu.inc Stores the menu router if we have it in memory.
_menu_router_save core/includes/menu.inc Saves data from menu_router_build() to the router table.
_menu_set_expanded_menus core/includes/menu.inc Updates a list of menus with expanded items.
_menu_site_is_offline core/includes/menu.inc Checks whether the site is in maintenance mode.
_menu_translate core/includes/menu.inc Handles dynamic path translation and menu access control.
_menu_tree_check_access core/includes/menu.inc Sorts the menu tree and recursively checks access for each item.
_menu_tree_data core/includes/menu.inc Builds the data representing a menu tree.
_menu_update_parental_status core/includes/menu.inc Checks and updates the 'has_children' status for the parent of a link.

Constants

Namesort descending Location Description
MENU_ACCESS_DENIED core/includes/menu.inc Menu status code -- Access denied.
MENU_CALLBACK core/includes/menu.inc Menu type -- A hidden, internal callback, typically used for API calls.
MENU_CONTEXT_INLINE core/includes/menu.inc Internal menu flag: Local task should be displayed inline.
MENU_CONTEXT_NONE core/includes/menu.inc Internal menu flag: Invisible local task.
MENU_CONTEXT_PAGE core/includes/menu.inc Internal menu flag: Local task should be displayed in page context.
MENU_CREATED_BY_ADMIN core/includes/menu.inc Internal menu flag -- menu item was created by administrator.
MENU_DEFAULT_LOCAL_TASK core/includes/menu.inc Menu type -- The "default" local task, which is initially active.
MENU_FOUND core/includes/menu.inc Internal menu status code -- Menu item was found.
MENU_IS_LOCAL_ACTION core/includes/menu.inc Internal menu flag -- menu item is a local action.
MENU_IS_LOCAL_TASK core/includes/menu.inc Internal menu flag -- menu item is a local task.
MENU_IS_ROOT core/includes/menu.inc Internal menu flag -- menu item is the root of the menu tree.
MENU_LINKS_TO_PARENT core/includes/menu.inc Internal menu flag -- menu item links back to its parent.
MENU_LOCAL_ACTION core/includes/menu.inc Menu type -- An action specific to the parent, usually rendered as a link.
MENU_LOCAL_TASK core/includes/menu.inc Menu type -- A task specific to the parent item, usually rendered as a tab.
MENU_MAX_DEPTH core/includes/menu.inc The maximum depth of a menu links tree - matches the number of p columns.
MENU_MAX_PARTS core/includes/menu.inc The maximum number of path elements for a menu callback
MENU_MODIFIED_BY_ADMIN core/includes/menu.inc Internal menu flag -- menu item can be modified by administrator.
MENU_NORMAL_ITEM core/includes/menu.inc Menu type -- A "normal" menu item that's shown in menu and breadcrumbs.
MENU_NOT_FOUND core/includes/menu.inc Menu status code -- Not found.
MENU_PREFERRED_LINK core/includes/menu.inc Reserved key to identify the most specific menu link for a given path.
MENU_SITE_OFFLINE core/includes/menu.inc Internal menu status code -- Menu item inaccessible because site is offline.
MENU_SITE_ONLINE core/includes/menu.inc Internal menu status code -- Everything is working fine.
MENU_SUGGESTED_ITEM core/includes/menu.inc Menu type -- A normal menu item, hidden until enabled by an administrator.
MENU_VISIBLE_IN_BREADCRUMB core/includes/menu.inc Internal menu flag -- menu item is visible in the breadcrumb.
MENU_VISIBLE_IN_TREE core/includes/menu.inc Internal menu flag -- menu item is visible in the menu tree.

Sub-Topics

Namesort descending Location Description
Menu context types core/includes/menu.inc Flags for use in the "context" attribute of menu router items.
Menu flags core/includes/menu.inc Flags for use in the "type" attribute of menu items.
Menu item types core/includes/menu.inc Definitions for various menu item types.
Menu status codes core/includes/menu.inc Status codes for menu callbacks.
Menu tree parameters core/includes/menu.inc Parameters for a menu tree.