menu_link_content.module in Drupal 8

Allows administrators to create custom menu links.

File

core/modules/menu_link_content/menu_link_content.module

<?php

/**
 * @file
 * Allows administrators to create custom menu links.
 */
use Drupal\Core\Url;
use Drupal\Core\Entity\EntityInterface;
use Drupal\path_alias\PathAliasInterface;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\system\MenuInterface;

/**
 * Implements hook_help().
 */
function menu_link_content_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    case 'help.page.menu_link_content':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('The Custom Menu Links module allows users to create menu links. These links can be translated if multiple languages are used for the site.');
      if (\Drupal::moduleHandler()
        ->moduleExists('menu_ui')) {
        $output .= ' ' . t('It is required by the Menu UI module, which provides an interface for managing menus and menu links. For more information, see the <a href=":menu-help">Menu UI module help page</a> and the <a href=":drupal-org-help">online documentation for the Custom Menu Links module</a>.', [
          ':menu-help' => Url::fromRoute('help.page', [
            'name' => 'menu_ui',
          ])
            ->toString(),
          ':drupal-org-help' => 'https://www.drupal.org/documentation/modules/menu_link',
        ]);
      }
      else {
        $output .= ' ' . t('For more information, see the <a href=":drupal-org-help">online documentation for the Custom Menu Links module</a>. If you enable the Menu UI module, it provides an interface for managing menus and menu links.', [
          ':drupal-org-help' => 'https://www.drupal.org/documentation/modules/menu_link',
        ]);
      }
      $output .= '</p>';
      return $output;
  }
}

/**
 * Implements hook_entity_type_alter().
 */
function menu_link_content_entity_type_alter(array &$entity_types) {

  // @todo Moderation is disabled for custom menu links until when we have an UI
  //   for them.
  //   @see https://www.drupal.org/project/drupal/issues/2350939
  $entity_types['menu_link_content']
    ->setHandlerClass('moderation', '');
}

/**
 * Implements hook_menu_delete().
 */
function menu_link_content_menu_delete(MenuInterface $menu) {
  $storage = \Drupal::entityTypeManager()
    ->getStorage('menu_link_content');
  $menu_links = $storage
    ->loadByProperties([
    'menu_name' => $menu
      ->id(),
  ]);
  $storage
    ->delete($menu_links);
}

/**
 * Implements hook_ENTITY_TYPE_insert() for 'path_alias'.
 */
function menu_link_content_path_alias_insert(PathAliasInterface $path_alias) {
  _menu_link_content_update_path_alias($path_alias
    ->getAlias());
}

/**
 * Helper function to update plugin definition using internal scheme.
 *
 * @param string $path
 *   The path alias.
 */
function _menu_link_content_update_path_alias($path) {

  /** @var \Drupal\Core\Menu\MenuLinkManagerInterface $menu_link_manager */
  $menu_link_manager = \Drupal::service('plugin.manager.menu.link');

  /** @var \Drupal\menu_link_content\MenuLinkContentInterface[] $entities */
  $entities = \Drupal::entityTypeManager()
    ->getStorage('menu_link_content')
    ->loadByProperties([
    'link.uri' => 'internal:' . $path,
  ]);
  foreach ($entities as $menu_link) {
    $menu_link_manager
      ->updateDefinition($menu_link
      ->getPluginId(), $menu_link
      ->getPluginDefinition(), FALSE);
  }
}

/**
 * Implements hook_ENTITY_TYPE_update() for 'path_alias'.
 */
function menu_link_content_path_alias_update(PathAliasInterface $path_alias) {
  if ($path_alias
    ->getAlias() != $path_alias->original
    ->getAlias()) {
    _menu_link_content_update_path_alias($path_alias
      ->getAlias());
    _menu_link_content_update_path_alias($path_alias->original
      ->getAlias());
  }
  elseif ($path_alias
    ->getPath() != $path_alias->original
    ->getPath()) {
    _menu_link_content_update_path_alias($path_alias
      ->getAlias());
  }
}

/**
 * Implements hook_ENTITY_TYPE_delete() for 'path_alias'.
 */
function menu_link_content_path_alias_delete(PathAliasInterface $path_alias) {
  _menu_link_content_update_path_alias($path_alias
    ->getAlias());
}

/**
 * Implements hook_entity_predelete().
 */
function menu_link_content_entity_predelete(EntityInterface $entity) {

  /** @var \Drupal\Core\Menu\MenuLinkManagerInterface $menu_link_manager */
  $menu_link_manager = \Drupal::service('plugin.manager.menu.link');
  $entity_type_id = $entity
    ->getEntityTypeId();
  foreach ($entity
    ->uriRelationships() as $rel) {
    $url = $entity
      ->toUrl($rel);

    // Entities can provide uri relationships that are not routed, in this case
    // getRouteParameters() will throw an exception.
    if (!$url
      ->isRouted()) {
      continue;
    }
    $route_parameters = $url
      ->getRouteParameters();
    if (!isset($route_parameters[$entity_type_id])) {

      // Do not delete links which do not relate to this exact entity. For
      // example, "collection", "add-form", etc.
      continue;
    }

    // Delete all MenuLinkContent links that point to this entity route.
    $result = $menu_link_manager
      ->loadLinksByRoute($url
      ->getRouteName(), $route_parameters);
    if ($result) {
      foreach ($result as $id => $instance) {
        if ($instance
          ->isDeletable() && strpos($id, 'menu_link_content:') === 0) {
          $instance
            ->deleteLink();
        }
      }
    }
  }
}

Functions

Name	Description
menu_link_content_entity_predelete	Implements hook_entity_predelete().
menu_link_content_entity_type_alter	Implements hook_entity_type_alter().
menu_link_content_help	Implements hook_help().
menu_link_content_menu_delete	Implements hook_menu_delete().
menu_link_content_path_alias_delete	Implements hook_ENTITY_TYPE_delete() for 'path_alias'.
menu_link_content_path_alias_insert	Implements hook_ENTITY_TYPE_insert() for 'path_alias'.
menu_link_content_path_alias_update	Implements hook_ENTITY_TYPE_update() for 'path_alias'.
_menu_link_content_update_path_alias	Helper function to update plugin definition using internal scheme.