Respond to a custom menu update.
This hook is used to notify modules that a custom menu has been updated. Contributed modules may use the information to perform actions based on the information entered into the menu system.
\Drupal\system\Plugin\Core\Entity\Menu $menu: A menu entity.
Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.
function hook_menu_update($menu) {
// For example, we track available menus in a variable.
$my_menus = variable_get('my_module_menus', array());
$my_menus[$menu
->id()] = $menu
->id();
variable_set('my_module_menus', $my_menus);
}