menu.module

  1. drupal
    1. 5
    2. 6
    3. 7
    4. 8

Allows administrators to customize the site navigation menu.

Functions & methods

NameDescription
menu_blockImplementation of hook_block().
menu_configureMenu callback; presents menu configuration options.
menu_confirm_disable_itemMenu callback; hide a menu item.
menu_confirm_disable_item_submit
menu_delete_itemDelete a menu item from the database. If $item['mid'] is specified, then this is used to find the existing item; otherwise, $item['path'] is used.
menu_edit_item_formPresent the menu item editing form.
menu_edit_item_form_submitProcess menu and menu item add/edit form submissions.
menu_edit_item_saveSave changes to a menu item into the database.
menu_edit_menu_formMenu callback; handle the adding/editing of a new menu.
menu_form_alterImplementation of hook_form_alter(). Add menu item fields to the node form.
menu_helpImplementation of hook_help().
menu_item_delete_formMenu callback; delete a single custom item.
menu_item_delete_form_submitProcess menu delete form submissions.
menu_menuImplementation of hook_menu().
menu_nodeapiImplementation of hook_nodeapi().
menu_node_form_deleteRemove the menu item.
menu_overviewMenu callback; present the main menu management page.
menu_overview_treePresent the menu tree, rendered along with links to edit menu items.
menu_overview_tree_rows
menu_parent_optionsReturn a list of menu items that are valid possible parents for the given menu item. The list excludes the given item and its children.
menu_permImplementation of hook_perm().
menu_reset_itemMenu callback; reset a single modified item.
menu_reset_item_submitProcess menu reset item form submissions.
menu_save_itemSave a menu item to the database.
View source
<?php

/**
 * @file
 * Allows administrators to customize the site navigation menu.
 */

/**
 * Implementation of hook_help().
 */
function menu_help($section) {
  switch ($section) {
    case 'admin/help#menu':
      $output = t('<p>Menus are a collection of links (menu items) used to navigate a website. The menu module provides an interface to control and customize the powerful menu system that comes with Drupal. Menus are primarily displayed as a hierarchical list of links using Drupal\'s highly flexible <a href="@admin-block">blocks</a> feature. Each menu automatically creates a block of the same name. By default, new menu items are placed inside a built-in menu labelled %navigation, but administrators can also create custom menus.</p>
<p>Drupal themes generally provide out-of-the-box support for two menus commonly labelled %primary-links and %secondary-links. These are sets of links which are usually displayed in the header or footer of each page (depending on the currently active theme). Any menu can be designated as the primary or secondary links menu via the <a href="@menu-settings">menu settings page</a>.</p>
Menu administration tabs:
<ul>
  <li>On the administer menu page, administrators can "edit" to change the title, description, parent or weight of a menu item. Under the "operations" column, click on "enable/disable" to toggle a menu item on or off. Only menu items which are enabled are displayed in the corresponding menu block. Note that the default menu items generated by the menu module cannot be deleted, only disabled.</li>
  <li>Use the "add menu" tab to submit a title for a new custom menu. Once submitted, the menu will appear in a list toward the bottom of the administer menu page underneath the main navigation menu. Under the menu name there will be links to edit or delete the menu, and a link to add new items to the menu.</li>
  <li>Use the "add menu item" tab to create new links in either the navigation or a custom menu (such as a primary/secondary links menu). Select the parent item to place the new link within an existing menu structure. For top level menu items, choose the name of the menu in which the link is to be added.</li>
</ul>', array('%navigation' => 'Navigation', '%primary-links' => 'primary links', '%secondary-links' => 'secondary links', '@admin-block' => url('admin/build/block'), '@menu-settings' => url('admin/build/menu/settings')));
      $output .= '<p>'. t('For more information please read the configuration and customization handbook <a href="@menu">Menu page</a>.', array('@menu' => 'http://drupal.org/handbook/modules/menu/')) .'</p>';
      return $output;
    case 'admin/build/menu':
      return '<p>'. t('Menus are a collection of links (menu items) used to navigate a website. The list(s) below display the currently available menus along with their menu items. Select an operation from the list to manage each menu or menu item.', array('@admin-settings-menus' => url('admin/build/menu/settings'), '@admin-block'=> url('admin/build/block'))) .'</p>';
    case 'admin/build/menu/menu/add':
      return '<p>'. t('Enter the name for your new menu. Remember to enable the newly created block in the <a href="@blocks">blocks administration page</a>.', array('@blocks' => url('admin/build/block'))) .'</p>';
    case 'admin/build/menu/item/add':
      return '<p>'. t('Enter the title, path, position and the weight for your new menu item.') .'</p>';
  }
}

/**
 * Implementation of hook_menu().
 */
function menu_menu($may_cache) {
  $items = array();

  if ($may_cache) {
    $items[] = array('path' => 'admin/build/menu',
      'title' => t('Menus'),
      'description' => t("Control your site's navigation menu, primary links and secondary links. as well as rename and reorganize menu items."),
      'callback' => 'menu_overview',
      'access' => user_access('administer menu'));
    $items[] = array('path' => 'admin/build/menu/list',
      'title' => t('List'),
      'type' => MENU_DEFAULT_LOCAL_TASK,
      'weight' => -10);

    $items[] = array('path' => 'admin/build/menu/item/add',
      'title' => t('Add menu item'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('menu_edit_item_form', 'add'),
      'access' => user_access('administer menu'),
      'type' => MENU_LOCAL_TASK);
    $items[] = array('path' => 'admin/build/menu/item/edit',
      'title' => t('Edit menu item'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('menu_edit_item_form', 'edit'),
      'access' => user_access('administer menu'),
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/build/menu/item/reset',
      'title' => t('Reset menu item'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('menu_reset_item'),
      'access' => user_access('administer menu'),
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/build/menu/item/disable',
      'title' => t('Disable menu item'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('menu_confirm_disable_item'),
      'access' => user_access('administer menu'),
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/build/menu/item/delete',
      'title' => t('Delete menu item'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('menu_item_delete_form'),
      'access' => user_access('administer menu'),
      'type' => MENU_CALLBACK);

    $items[] = array('path' => 'admin/build/menu/menu/add',
      'title' => t('Add menu'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('menu_edit_menu_form', 'add'),
      'access' => user_access('administer menu'),
      'type' => MENU_LOCAL_TASK);
    $items[] = array('path' => 'admin/build/menu/menu/edit',
      'title' => t('Edit menu'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('menu_edit_menu_form', 'edit'),
      'access' => user_access('administer menu'),
      'type' => MENU_CALLBACK);
    $items[] = array('path' => 'admin/build/menu/menu/delete',
      'title' => t('Delete menu'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('menu_item_delete_form'),
      'access' => user_access('administer menu'),
      'type' => MENU_CALLBACK);

    $items[] = array('path' => 'admin/build/menu/settings',
      'title' => t('Settings'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('menu_configure'),
      'type' => MENU_LOCAL_TASK,
      'weight' => 5,
    );
  }

  return $items;
}

/**
 * Implementation of hook_block().
 */
function menu_block($op = 'list', $delta = 0) {
  if ($op == 'list') {
    $blocks = array();
    $root_menus = menu_get_root_menus();
    foreach ($root_menus as $mid => $title) {
      // Default "Navigation" block is handled by user.module.
      if ($mid != 1) {
        $blocks[$mid]['info'] = $title;
      }
    }
    return $blocks;
  }
  else if ($op == 'view') {
    $item = menu_get_item($delta);
    $data['subject'] = check_plain($item['title']);
    $data['content'] = theme('menu_tree', $delta);
    return $data;
  }
}

/**
 * Implementation of hook_nodeapi().
 */
function menu_nodeapi(&$node, $op) {

  if (user_access('administer menu')) {
    switch ($op) {
      case 'insert':
      case 'update':
        if ($node->menu['delete']) {
          menu_node_form_delete($node);
          menu_rebuild();
        }
        elseif ($node->menu['title']) {
          $node->menu['path'] = ($node->menu['path']) ? $node->menu['path'] : "node/$node->nid";
          menu_edit_item_save($node->menu);
          menu_rebuild();
        }
        break;

      case 'delete':
        menu_node_form_delete($node);
        menu_rebuild();
        break;
    }
  }
}

/**
 * Implementation of hook_perm().
 */
function menu_perm() {
  return array('administer menu');
}

/**
 * Implementation of hook_form_alter().
 * Add menu item fields to the node form.
 */
function menu_form_alter($form_id, &$form) {
  if (isset($form['type']) && $form['type']['#value'] .'_node_form' == $form_id) {
    $item = array();
    if ($form['nid']['#value'] > 0) {
      $item = db_fetch_array(db_query("SELECT * FROM {menu} WHERE path = 'node/%d' ORDER BY mid", $form['nid']['#value']));
      if (isset($form['#post']['menu']) && is_array($form['#post']['menu'])) {
        $item = !is_array($item) ? $form['#post']['menu'] : (($form['#post']['op'] == t('Preview')) ? array_merge($item, $form['#post']['menu']) : array_merge($form['#post']['menu'], $item));
      }
    }

    $form['menu'] = array('#type' => 'fieldset',
      '#title' => t('Menu settings'),
      '#access' => user_access('administer menu'),
      '#collapsible' => TRUE,
      '#collapsed' => empty($item['title']),
      '#tree' => TRUE,
      '#weight' => 30,
    );

    $form['menu']['title'] = array('#type' => 'textfield',
      '#title' => t('Title'),
      '#default_value' => $item['title'],
      '#description' => t('The name to display for this menu link.'),
    );

    $form['menu']['description'] = array('#type' => 'textfield',
      '#title' => t('Description'),
      '#default_value' => $item['description'],
      '#description' => t('The description displayed when hovering over a menu item.'),
    );

    // Generate a list of possible parents.
    $options = menu_parent_options($item['mid'], variable_get('menu_parent_items', 0));

    $form['menu']['pid'] = array('#type' => 'select',
      '#title' => t('Parent item'),
      '#default_value' => $item['pid'],
      '#options' => $options,
    );

    $form['menu']['path'] = array('#type' => 'hidden',
      '#value' => $item['path'],
    );

    $form['menu']['weight'] = array('#type' => 'weight',
      '#title' => t('Weight'),
      '#default_value' => $item['weight'],
      '#delta' => 10,
      '#description' => t('Optional. In the menu, the heavier items will sink and the lighter items will be positioned nearer the top.'),
    );

    $form['menu']['mid'] = array('#type' => 'hidden',
      '#value' => $item['mid'] ? $item['mid'] : 0,
    );

    $form['menu']['type'] = array('#type' => 'hidden',
      '#value' => $item['type'] ? $item['type'] : MENU_CUSTOM_ITEM,
    );

    if ($item['mid'] > 0) {
      $form['menu']['delete'] = array('#type' => 'checkbox',
        '#title' => t('Check to delete this menu item.'),
        '#default_value' => $item['delete'],
      );

      $form['menu']['advanced'] = array('#type' => 'item',
        '#value' => t('You may also <a href="@edit">edit the advanced settings</a> for this menu item.', array('@edit' => url("admin/build/menu/item/edit/{$item['mid']}"))),
      );
    }
  }
}

/**
 * Menu callback; presents menu configuration options.
 */
function menu_configure() {
  $root_menus = menu_get_root_menus();

  $primary_options = $root_menus;
  $primary_options[0] = t('No primary links');

  $form['settings_links'] = array('#type' => 'fieldset',
    '#title' => t('Primary and secondary links settings'),
  );

  $form['settings_links']['intro'] = array('#type' => 'item',
    '#value' => t('Primary and secondary links provide a navigational menu system which usually (depending on your theme) appears at the top-right of the browser window. The links displayed can be generated either from a custom list created via the <a href="@menu">menu administration</a> page or from a built-in list of menu items such as the navigation menu links.', array('@menu' => url('admin/build/menu'))),
  );

  $form['settings_links']['menu_primary_menu'] = array('#type' => 'select',
    '#title' => t('Menu containing primary links'),
    '#default_value' => variable_get('menu_primary_menu', 0),
    '#options' => $primary_options,
  );

  $secondary_options = $root_menus;
  $secondary_options[0] = t('No secondary links');

  $form['settings_links']['menu_secondary_menu'] = array('#type' => 'select',
    '#title' => t('Menu containing secondary links'),
    '#default_value' => variable_get('menu_secondary_menu', 0),
    '#options' => $secondary_options,
    '#description' => t('If you select the same menu as primary links then secondary links will display the appropriate second level of your navigation hierarchy.'),
  );

  $form['settings_authoring'] = array('#type' => 'fieldset',
    '#title' => t('Content authoring form settings'),
  );

  $form['settings_authoring']['intro'] = array('#type' => 'item',
    '#value' => t('The menu module allows on-the-fly creation of menu links in the content authoring forms. The following option limits the menus in which a new link may be added. E.g., this can be used to force new menu items to be created in the primary links menu or to hide admin menu items.'),
  );

  $authoring_options = $root_menus;
  $authoring_options[0] = t('Show all menus');

  $form['settings_authoring']['menu_parent_items'] = array('#type' => 'select',
    '#title' => t('Restrict parent items to'),
    '#default_value' => variable_get('menu_parent_items', 0),
    '#options' => $authoring_options,
    '#description' => t('Choose the menu to be made available in the content authoring form. Only this menu item and its children will be shown.'),
   );

  return system_settings_form($form);
}

/**
 * Menu callback; handle the adding/editing of a new menu.
 */
function menu_edit_menu_form($type, $mid = 0) {
  if ($type == 'edit') {
    if (!($item = db_fetch_array(db_query('SELECT * FROM {menu} WHERE mid = %d', $mid)))) {
      drupal_not_found();
      return;
    }
  }
  else {
    $item = array('mid' => 0, 'pid' => 0, 'path' => '', 'weight' => 0, 'type' => MENU_CUSTOM_MENU);
  }
  $form['title'] = array('#type' => 'textfield',
    '#title' => t('Title'),
    '#default_value' => $item['title'],
    '#description' => t('The name of the menu.'),
    '#required' => TRUE,
  );
  $form['mid'] = array('#type' => 'value', '#value' => $item['mid']);
  $form['pid'] = array('#type' => 'value', '#value' => $item['pid']);
  $form['path'] = array('#type' => 'value', '#value' => $item['path']);
  $form['weight'] = array('#type' => 'value', '#value' => $item['weight']);
  $form['type'] = array('#type' => 'value', '#value' => $item['type']);
  $form['submit'] = array('#type' => 'submit', '#value' => t('Submit'));
  // Reuse the submit function of menu_edit_item_form.
  $form['#base'] = 'menu_edit_item_form';

  return $form;
}

/**
 * Present the menu item editing form.
 */
function menu_edit_item_form($type, $mid = 0) {
  if ($type == 'edit') {
    if (!($item = db_fetch_array(db_query('SELECT * FROM {menu} WHERE mid = %d', $mid)))) {
      drupal_not_found();
      return;
    }
  }
  else {
    // This is an add form.
    // The mid argument (if set) will be the default pid to use.
    // Otherwise, we default to the "Navigation" menu (pid #1).
    $default_pid = $mid ? $mid : 1;
    $item = array('mid' => 0, 'pid' => $default_pid, 'weight' => 0, 'type' => MENU_CUSTOM_ITEM);
  }

  $form['title'] = array('#type' => 'textfield',
    '#title' => t('Title'),
    '#default_value' => $item['title'],
    '#description' => t('The name of the menu item.'),
    '#required' => TRUE,
  );
  $form['description'] = array('#type' => 'textfield',
    '#title' => t('Description'),
    '#default_value' => $item['description'],
    '#description' => t('The description displayed when hovering over a menu item.'),
    '#maxlength' => 255,
  );

  if ($item['type'] & MENU_CREATED_BY_ADMIN) {
    $form['path'] = array('#type' => 'textfield',
      '#title' => t('Path'),
      '#default_value' => $item['path'],
      '#description' => t('The path this menu item links to. This can be an internal Drupal path such as %add-node or an external URL such as %drupal. Enter %front to link to the front page.', array('%front' => '<front>', '%add-node' => 'node/add', '%drupal' => 'http://drupal.org')),
      '#required' => TRUE,
    );
  }
  else {
    $form['_path'] = array('#type' => 'item',
      '#title' => t('Path'),
      '#description' => l($item['path'], $item['path']),
    );
    $form['path'] = array('#type' => 'value', '#value' => $item['path']);
  }

  $expanded = $item['type'] & MENU_EXPANDED ? 1 : 0;
  $form['expanded'] = array('#type' => 'checkbox',
    '#title' => t('Expanded'),
    '#default_value' => $expanded,
    '#description' => t('If selected and this menu item has children, the menu will always appear expanded.'),
  );

  // Generate a list of possible parents (not including this item or descendants).
  $options = menu_parent_options($item['mid']);
  $form['pid'] = array('#type' => 'select',
    '#title' => t('Parent item'),
    '#default_value' => $item['pid'],
    '#options' => $options,
  );
  $form['weight'] = array('#type' => 'weight',
    '#title' => t('Weight'),
    '#default_value' => $item['weight'],
    '#description' => t('Optional. In the menu, the heavier items will sink and the lighter items will be positioned nearer the top.'),
  );

  // Always enable menu items (but not menus) when editing them, unless already
  // conditionally visible.
  if (!($item['type'] & (MENU_IS_ROOT | MENU_VISIBLE_IF_HAS_CHILDREN))) {
    $item['type'] |= MENU_VISIBLE_IN_TREE | MENU_VISIBLE_IN_BREADCRUMB;
  }

  $form['type'] = array('#type' => 'value', '#value' => $item['type']);
  $form['mid'] = array('#type' => 'value', '#value' => $item['mid']);
  $form['submit'] = array('#type' => 'submit', '#value' => t('Submit'));

  return $form;
}

/**
 * Process menu and menu item add/edit form submissions.
 */
function menu_edit_item_form_submit($form_id, $form_values) {
  menu_edit_item_save($form_values);
  return 'admin/build/menu';
}

/**
 * Menu callback; delete a single custom item.
 */
function menu_item_delete_form($mid) {
  if (!($menu = db_fetch_object(db_query('SELECT type, title FROM {menu} WHERE mid = %d', $mid)))) {
    drupal_not_found();
    return;
  }

  $form['mid'] = array('#type' => 'value', '#value' => $mid);
  $form['type'] = array('#type' => 'value', '#value' => $menu->type);
  $form['title'] = array('#type' => 'value', '#value' => $menu->title);

  if ($menu->type & MENU_IS_ROOT) {
    $message = t('Are you sure you want to delete the menu %item?', array('%item' => $menu->title));
  }
  else {
    $message = t('Are you sure you want to delete the custom menu item %item?', array('%item' => $menu->title));
  }

  return confirm_form($form, $message, 'admin/build/menu', t('This action cannot be undone.'), t('Delete'));
}

/**
 * Process menu delete form submissions.
 */
function menu_item_delete_form_submit($form_id, $form_values) {
  menu_delete_item($form_values['mid']);

  $t_args = array('%title' => $form_values['title']);
  if ($form_values['type'] & MENU_IS_ROOT) {
    drupal_set_message(t('The menu %title has been deleted.', $t_args));
    watchdog('menu', t('Deleted menu %title.', $t_args), WATCHDOG_NOTICE);
  }
  else {
    drupal_set_message(t('The menu item %title has been deleted.', $t_args));
    watchdog('menu', t('Deleted menu item %title.', $t_args), WATCHDOG_NOTICE);
  }

  return 'admin/build/menu';
}

/**
 * Menu callback; reset a single modified item.
 */
function menu_reset_item($mid) {
  if (isset($mid) && $title = db_result(db_query('SELECT title FROM {menu} WHERE mid = %d', $mid))) {
    $form['mid'] = array('#type' => 'value', '#value' => $mid);
    return confirm_form($form, t('Are you sure you want to reset the item %item to its default values?', array('%item' => $title)), 'admin/build/menu', t('Any customizations will be lost. This action cannot be undone.'), t('Reset'));
  }
  else {
    drupal_not_found();
  }
}

/**
 * Process menu reset item form submissions.
 */
function menu_reset_item_submit($form_id, $form_values) {
  menu_delete_item($form_values['mid']);
  drupal_set_message(t('The menu item was reset to its default settings.'));

  return 'admin/build/menu';
}

/**
 * Menu callback; hide a menu item.
 *
 * Presents a confirmation form to protect against cross site request forgeries.
 */
function menu_confirm_disable_item($mid, $token = NULL) {
  global $user;
  $item = menu_get_item($mid);
  $form = array();
  $form['mid'] = array('#type' => 'value', '#value' => $mid);
  $form['item'] = array('#type' => 'value', '#value' => $item);
  return confirm_form($form, t('Are you sure you want to disable the menu item %menu-item?', array('%menu-item' =>  $item['title'])), 'admin/build/menu', ' ', t('Disable'), t('Cancel'));
}

function menu_confirm_disable_item_submit($form_id, $form_values) {
  $type = $form_values['item']['type'];
  $type &= ~MENU_VISIBLE_IN_TREE;
  $type &= ~MENU_VISIBLE_IN_BREADCRUMB;
  $type |= MENU_MODIFIED_BY_ADMIN;
  db_query('UPDATE {menu} SET type = %d WHERE mid = %d', $type, $form_values['mid']);
  drupal_set_message(t('The menu item has been disabled.'));
  drupal_goto('admin/build/menu');
}

/**
 * Menu callback; present the main menu management page.
 */
function menu_overview() {
  menu_rebuild();

  return menu_overview_tree();
}

/**
 * Save changes to a menu item into the database.
 *
 * @return mid
 */
function menu_edit_item_save($edit) {
  if (isset($edit['expanded'])) {
    if ($edit['expanded']) {
      $edit['type'] |= MENU_EXPANDED;
    }
    else {
      $edit['type'] &= ~MENU_EXPANDED;
    }
  }

  $edit['type'] = $edit['type'] | MENU_MODIFIED_BY_ADMIN;

  $status = menu_save_item($edit);

  $t_args = array('%title' => $edit['title']);
  if ($status == SAVED_UPDATED) {
    drupal_set_message(t('The menu item %title has been updated.', $t_args));
  }
  elseif ($status == SAVED_NEW) {
    drupal_set_message(t('The menu item %title has been added.', $t_args));
    watchdog('menu', t('Added menu item %title.', $t_args), WATCHDOG_NOTICE, l(t('view'), 'admin/build/menu'));
  }
  return $edit['mid'];
}

/**
 * Save a menu item to the database.
 *
 * @param $item
 *   The menu item to be saved. This is passed by reference, so that the newly
 *   generated $item['mid'] can be accessed after an insert takes place.
 *
 * @return $status
 *   The operation that was performed in saving. Either SAVED_NEW (if a new
 *   menu item was created), or SAVED_UPDATED (if an existing menu item was
 *   updated).
 */
function menu_save_item(&$item) {
  $existing_item = NULL;

  // Check that the item already exists in the menu tree, if $item['mid'] is
  // specified.
  if (isset($item['mid'])) {
    $existing_item = menu_get_item($item['mid']);
  }

  if ($item['mid'] && !empty($existing_item)) {
    db_query("UPDATE {menu} SET pid = %d, path = '%s', title = '%s', description = '%s', weight = %d, type = %d WHERE mid = %d", $item['pid'], $item['path'], $item['title'], $item['description'], $item['weight'], $item['type'], $item['mid']);
    return SAVED_UPDATED;
  }
  else {
    $item['mid'] = db_next_id('{menu}_mid');
    // Check explicitly for mid <= 2. If the database was improperly prefixed,
    // this would cause a nasty infinite loop or duplicate mid errors.
    // TODO: have automatic prefixing through an installer to prevent this.
    while ($item['mid'] <= 2) {
      $item['mid'] = db_next_id('{menu}_mid');
    }
    db_query("INSERT INTO {menu} (mid, pid, path, title, description, weight, type) VALUES (%d, %d, '%s', '%s', '%s', %d, %d)", $item['mid'], $item['pid'], $item['path'], $item['title'], $item['description'], $item['weight'], $item['type']);
    return SAVED_NEW;
  }
}

/**
 * Delete a menu item from the database. If $item['mid'] is specified, then
 * this is used to find the existing item; otherwise, $item['path'] is used.
 *
 * @param $item
 *   The menu item to be deleted.
 */
function menu_delete_item($item) {
  if (!is_array($item)) {
    $item = array('mid' => $item);
  }

  if ($item['mid']) {
    db_query('DELETE FROM {menu} WHERE mid = %d', $item['mid']);
  }
  elseif ($item['path']) {
    db_query("DELETE FROM {menu} WHERE path = '%s'", $item['path']);
  }
}

/**
 * Present the menu tree, rendered along with links to edit menu items.
 */
function menu_overview_tree() {
  $menu = menu_get_menu();
  $root_menus = menu_get_root_menus();
  $header = array(t('Menu item'), t('Expanded'), array('data' => t('Operations'), 'colspan' => '3'));
  $output = '';

  // We reverse the root menu to show user created menus first.
  foreach (array_reverse($root_menus, true) as $mid => $title) {
    $operations = array();
    if ($menu['items'][$mid]['type'] & MENU_MODIFIABLE_BY_ADMIN) {
      $operations[] = l(t('Edit'), 'admin/build/menu/menu/edit/'. $mid);
    }
    if ($menu['items'][$mid]['type'] & MENU_CREATED_BY_ADMIN) {
      $operations[] = l(t('Delete'), 'admin/build/menu/menu/delete/'. $mid);
    }
    $operations[] = l(t('Add item'), 'admin/build/menu/item/add/'. $mid);
    $table = theme('item_list', $operations);

    $rows = menu_overview_tree_rows($mid);
    $table .= theme('table', $header, $rows ? $rows : array(array(array('data' => t('No menu items defined.'), 'colspan' => 5))));

    $output .= theme('box', check_plain($title), $table);
  }
  return $output;
}

function menu_overview_tree_rows($pid = 0, $depth = 0) {
  $parent_item = menu_get_item($pid);
  $rows = array();

  if (isset($parent_item) && isset($parent_item['children'])) {
    usort($parent_item['children'], '_menu_sort');
    foreach ($parent_item['children'] as $mid) {
      $item = menu_get_item($mid);
      // Populate the title field.
      $title = '';
      if ($pid == 0) {
        // Top-level items are menu names, and don't have an associated path.
        $title .= check_plain($item['title']);
      }
      else {
        $title .= l($item['title'], $item['path']);
      }
      if ($depth > 0) {
        $title = '-&nbsp;'. $title;
      }
      for ($i = 1; $i < $depth; $i++) {
        $title = '&nbsp;&nbsp;'. $title;
      }

      // Populate the operations field.
      $operations = array();
      if (!($item['type'] & MENU_MODIFIABLE_BY_ADMIN)) {
        $operations[] = array('data' => t('locked'), 'colspan' => '3', 'align' => 'center');
      }
      else {
        // Set the edit column.
        if ($item['type'] & (MENU_VISIBLE_IN_TREE | MENU_VISIBLE_IF_HAS_CHILDREN)) {
          $operations[] = array('data' => l(t('edit'), 'admin/build/menu/item/edit/'. $mid));
        }
        else {
          $operations[] = array('data' => '');
        }

        // Set the disable column.
        if ($item['type'] & (MENU_IS_ROOT | MENU_VISIBLE_IF_HAS_CHILDREN)) {
          // Disabling entire menus is done from block admin page.
          // MENU_VISIBLE_IF_HAS_CHILDREN menus are always enabled so hide this operation.
          $operations[] = array('data' => '');
        }
        else if ($item['type'] & MENU_VISIBLE_IN_TREE) {
          $operations[] = array('data' => l(t('disable'), 'admin/build/menu/item/disable/'. $mid));
        }
        else {
          $operations[] = array('data' => l(t('enable'), 'admin/build/menu/item/edit/'. $mid));
        }

        // Set the reset column.
        if ($item['type'] & MENU_CREATED_BY_ADMIN) {
          $operations[] = array('data' => l(t('delete'), 'admin/build/menu/item/delete/'. $mid));
        }
        else if ($item['type'] & MENU_MODIFIED_BY_ADMIN) {
          $operations[] = array('data' => l(t('reset'), 'admin/build/menu/item/reset/'. $mid));
        }
        else {
          $operations[] = array('data' => '');
        }
      }

      // Call out disabled items.
      if ($item['type'] & (MENU_VISIBLE_IN_TREE | MENU_VISIBLE_IF_HAS_CHILDREN)) {
        $class = 'menu-enabled';
      }
      else {
        $title .= ' ('. t('disabled') .')';
        $class = 'menu-disabled';
      }

      if ($item['type'] & (MENU_MODIFIABLE_BY_ADMIN | MENU_VISIBLE_IN_TREE)) {
        $row = array(array('data' => $title, 'class' => $class), array('data' => ($item['children'] ? (($item['type'] & MENU_EXPANDED) ? t('Yes') : t('No')) : ''), 'class' => $class));
        foreach ($operations as $operation) {
          $operation['class'] = $class;
          $row[] = $operation;
        }
        $rows[] = $row;
        $rows = array_merge($rows, menu_overview_tree_rows($mid, $depth + 1));
      }
      else {
        // Skip items that are hidden and locked; admins will never care about them.
        $rows = array_merge($rows, menu_overview_tree_rows($mid, $depth));
      }
    }
  }

  return $rows;
}

/**
 * Return a list of menu items that are valid possible parents for the
 * given menu item. The list excludes the given item and its children.
 *
 * @param $mid
 *   The menu item id for which to generate a list of parents.
 *   If $mid == 0 then the complete tree is returned.
 * @param $pid
 *   The menu item id of the menu item at which to start the tree.
 *   If $pid > 0 then this item will be included in the tree.
 * @param $depth
 *   The current depth in the tree - used when recursing to indent the tree.
 * @return
 *   An array of menu titles keyed on the mid.
 */
function menu_parent_options($mid, $pid = 0, $depth = 0) {
  $options = array();

  if (!($parent_item = menu_get_item($pid))) {
    return $options;
  }

  // Exclude $mid and its children from the list unless $mid is 0.
  if ($mid && $mid == $pid) {
    return $options;
  }

  // Add the current $pid to the list.
  if ($pid > 0 && ($parent_item['type'] & (MENU_MODIFIABLE_BY_ADMIN | MENU_IS_ROOT))) {
    $title = ' '. $parent_item['title'];
    for ($i = 0; $i < $depth; $i++) {
      $title = '--'. $title;
    }
    if (!($parent_item['type'] & MENU_VISIBLE_IN_TREE)) {
      $title .= ' ('. t('disabled') .')';
    }
    $options[$pid] = $title;
    $depth ++;
  }

  // Add children of $pid to the list recursively.
  if (isset($parent_item['children'])) {
    usort($parent_item['children'], '_menu_sort');
    foreach ($parent_item['children'] as $child) {
      $options += menu_parent_options($mid, $child, $depth);
    }
  }

  return $options;
}

/**
 * Remove the menu item.
 */
function menu_node_form_delete($node) {
  menu_delete_item(array('path' => 'node/'. $node->nid));
}