Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\Menu;
Chris@0: 
Chris@0: use Drupal\Component\Utility\NestedArray;
Chris@0: use Drupal\Core\Access\AccessResultInterface;
Chris@0: use Drupal\Core\Cache\CacheableMetadata;
Chris@0: use Drupal\Core\Controller\ControllerResolverInterface;
Chris@0: use Drupal\Core\Routing\RouteProviderInterface;
Chris@0: use Drupal\Core\Template\Attribute;
Chris@0: 
Chris@0: /**
Chris@0:  * Implements the loading, transforming and rendering of menu link trees.
Chris@0:  */
Chris@0: class MenuLinkTree implements MenuLinkTreeInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The menu link tree storage.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Menu\MenuTreeStorageInterface
Chris@0:    */
Chris@0:   protected $treeStorage;
Chris@0: 
Chris@0:   /**
Chris@0:    * The menu link plugin manager.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Menu\MenuLinkManagerInterface
Chris@0:    */
Chris@0:   protected $menuLinkManager;
Chris@0: 
Chris@0:   /**
Chris@0:    * The route provider to load routes by name.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Routing\RouteProviderInterface
Chris@0:    */
Chris@0:   protected $routeProvider;
Chris@0: 
Chris@0:   /**
Chris@0:    * The active menu trail service.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Menu\MenuActiveTrailInterface
Chris@0:    */
Chris@0:   protected $menuActiveTrail;
Chris@0: 
Chris@0:   /**
Chris@0:    * The controller resolver.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Controller\ControllerResolverInterface
Chris@0:    */
Chris@0:   protected $controllerResolver;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a \Drupal\Core\Menu\MenuLinkTree object.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Menu\MenuTreeStorageInterface $tree_storage
Chris@0:    *   The menu link tree storage.
Chris@0:    * @param \Drupal\Core\Menu\MenuLinkManagerInterface $menu_link_manager
Chris@0:    *   The menu link plugin manager.
Chris@0:    * @param \Drupal\Core\Routing\RouteProviderInterface $route_provider
Chris@0:    *   The route provider to load routes by name.
Chris@0:    * @param \Drupal\Core\Menu\MenuActiveTrailInterface $menu_active_trail
Chris@0:    *   The active menu trail service.
Chris@0:    * @param \Drupal\Core\Controller\ControllerResolverInterface $controller_resolver
Chris@0:    *   The controller resolver.
Chris@0:    */
Chris@0:   public function __construct(MenuTreeStorageInterface $tree_storage, MenuLinkManagerInterface $menu_link_manager, RouteProviderInterface $route_provider, MenuActiveTrailInterface $menu_active_trail, ControllerResolverInterface $controller_resolver) {
Chris@0:     $this->treeStorage = $tree_storage;
Chris@0:     $this->menuLinkManager = $menu_link_manager;
Chris@0:     $this->routeProvider = $route_provider;
Chris@0:     $this->menuActiveTrail = $menu_active_trail;
Chris@0:     $this->controllerResolver = $controller_resolver;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getCurrentRouteMenuTreeParameters($menu_name) {
Chris@0:     $active_trail = $this->menuActiveTrail->getActiveTrailIds($menu_name);
Chris@0: 
Chris@0:     $parameters = new MenuTreeParameters();
Chris@0:     $parameters->setActiveTrail($active_trail)
Chris@0:       // We want links in the active trail to be expanded.
Chris@0:       ->addExpandedParents($active_trail)
Chris@0:       // We marked the links in the active trail to be expanded, but we also
Chris@0:       // want their descendants that have the "expanded" flag enabled to be
Chris@0:       // expanded.
Chris@0:       ->addExpandedParents($this->treeStorage->getExpanded($menu_name, $active_trail));
Chris@0: 
Chris@0:     return $parameters;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function load($menu_name, MenuTreeParameters $parameters) {
Chris@0:     $data = $this->treeStorage->loadTreeData($menu_name, $parameters);
Chris@0:     // Pre-load all the route objects in the tree for access checks.
Chris@0:     if ($data['route_names']) {
Chris@0:       $this->routeProvider->getRoutesByNames($data['route_names']);
Chris@0:     }
Chris@0:     return $this->createInstances($data['tree']);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Returns a tree containing of MenuLinkTreeElement based upon tree data.
Chris@0:    *
Chris@0:    * This method converts the tree representation as array coming from the tree
Chris@0:    * storage to a tree containing a list of MenuLinkTreeElement[].
Chris@0:    *
Chris@0:    * @param array $data_tree
Chris@0:    *   The tree data coming from the menu tree storage.
Chris@0:    *
Chris@0:    * @return \Drupal\Core\Menu\MenuLinkTreeElement[]
Chris@0:    *   An array containing the elements of a menu tree.
Chris@0:    */
Chris@0:   protected function createInstances(array $data_tree) {
Chris@0:     $tree = [];
Chris@0:     foreach ($data_tree as $key => $element) {
Chris@0:       $subtree = $this->createInstances($element['subtree']);
Chris@0:       // Build a MenuLinkTreeElement out of the menu tree link definition:
Chris@0:       // transform the tree link definition into a link definition and store
Chris@0:       // tree metadata.
Chris@0:       $tree[$key] = new MenuLinkTreeElement(
Chris@0:         $this->menuLinkManager->createInstance($element['definition']['id']),
Chris@0:         (bool) $element['has_children'],
Chris@0:         (int) $element['depth'],
Chris@0:         (bool) $element['in_active_trail'],
Chris@0:         $subtree
Chris@0:       );
Chris@0:     }
Chris@0:     return $tree;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function transform(array $tree, array $manipulators) {
Chris@0:     foreach ($manipulators as $manipulator) {
Chris@0:       $callable = $manipulator['callable'];
Chris@0:       $callable = $this->controllerResolver->getControllerFromDefinition($callable);
Chris@0:       // Prepare the arguments for the menu tree manipulator callable; the first
Chris@0:       // argument is always the menu link tree.
Chris@0:       if (isset($manipulator['args'])) {
Chris@0:         array_unshift($manipulator['args'], $tree);
Chris@0:         $tree = call_user_func_array($callable, $manipulator['args']);
Chris@0:       }
Chris@0:       else {
Chris@0:         $tree = call_user_func($callable, $tree);
Chris@0:       }
Chris@0:     }
Chris@0:     return $tree;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function build(array $tree) {
Chris@0:     $tree_access_cacheability = new CacheableMetadata();
Chris@0:     $tree_link_cacheability = new CacheableMetadata();
Chris@0:     $items = $this->buildItems($tree, $tree_access_cacheability, $tree_link_cacheability);
Chris@0: 
Chris@0:     $build = [];
Chris@0: 
Chris@0:     // Apply the tree-wide gathered access cacheability metadata and link
Chris@0:     // cacheability metadata to the render array. This ensures that the
Chris@0:     // rendered menu is varied by the cache contexts that the access results
Chris@0:     // and (dynamic) links depended upon, and invalidated by the cache tags
Chris@0:     // that may change the values of the access results and links.
Chris@0:     $tree_cacheability = $tree_access_cacheability->merge($tree_link_cacheability);
Chris@0:     $tree_cacheability->applyTo($build);
Chris@0: 
Chris@0:     if ($items) {
Chris@0:       // Make sure drupal_render() does not re-order the links.
Chris@0:       $build['#sorted'] = TRUE;
Chris@0:       // Get the menu name from the last link.
Chris@0:       $item = end($items);
Chris@0:       $link = $item['original_link'];
Chris@0:       $menu_name = $link->getMenuName();
Chris@0:       // Add the theme wrapper for outer markup.
Chris@0:       // Allow menu-specific theme overrides.
Chris@0:       $build['#theme'] = 'menu__' . strtr($menu_name, '-', '_');
Chris@0:       $build['#menu_name'] = $menu_name;
Chris@0:       $build['#items'] = $items;
Chris@0:       // Set cache tag.
Chris@0:       $build['#cache']['tags'][] = 'config:system.menu.' . $menu_name;
Chris@0:     }
Chris@0: 
Chris@0:     return $build;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Builds the #items property for a menu tree's renderable array.
Chris@0:    *
Chris@0:    * Helper function for ::build().
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Menu\MenuLinkTreeElement[] $tree
Chris@0:    *   A data structure representing the tree, as returned from
Chris@0:    *   MenuLinkTreeInterface::load().
Chris@0:    * @param \Drupal\Core\Cache\CacheableMetadata &$tree_access_cacheability
Chris@0:    *   Internal use only. The aggregated cacheability metadata for the access
Chris@0:    *   results across the entire tree. Used when rendering the root level.
Chris@0:    * @param \Drupal\Core\Cache\CacheableMetadata &$tree_link_cacheability
Chris@0:    *   Internal use only. The aggregated cacheability metadata for the menu
Chris@0:    *   links across the entire tree. Used when rendering the root level.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    *   The value to use for the #items property of a renderable menu.
Chris@0:    *
Chris@0:    * @throws \DomainException
Chris@0:    */
Chris@0:   protected function buildItems(array $tree, CacheableMetadata &$tree_access_cacheability, CacheableMetadata &$tree_link_cacheability) {
Chris@0:     $items = [];
Chris@0: 
Chris@0:     foreach ($tree as $data) {
Chris@0:       /** @var \Drupal\Core\Menu\MenuLinkInterface $link */
Chris@0:       $link = $data->link;
Chris@0:       // Generally we only deal with visible links, but just in case.
Chris@0:       if (!$link->isEnabled()) {
Chris@0:         continue;
Chris@0:       }
Chris@0: 
Chris@0:       if ($data->access !== NULL && !$data->access instanceof AccessResultInterface) {
Chris@0:         throw new \DomainException('MenuLinkTreeElement::access must be either NULL or an AccessResultInterface object.');
Chris@0:       }
Chris@0: 
Chris@0:       // Gather the access cacheability of every item in the menu link tree,
Chris@0:       // including inaccessible items. This allows us to render cache the menu
Chris@0:       // tree, yet still automatically vary the rendered menu by the same cache
Chris@0:       // contexts that the access results vary by.
Chris@0:       // However, if $data->access is not an AccessResultInterface object, this
Chris@0:       // will still render the menu link, because this method does not want to
Chris@0:       // require access checking to be able to render a menu tree.
Chris@0:       if ($data->access instanceof AccessResultInterface) {
Chris@0:         $tree_access_cacheability = $tree_access_cacheability->merge(CacheableMetadata::createFromObject($data->access));
Chris@0:       }
Chris@0: 
Chris@0:       // Gather the cacheability of every item in the menu link tree. Some links
Chris@0:       // may be dynamic: they may have a dynamic text (e.g. a "Hi, <user>" link
Chris@0:       // text, which would vary by 'user' cache context), or a dynamic route
Chris@0:       // name or route parameters.
Chris@0:       $tree_link_cacheability = $tree_link_cacheability->merge(CacheableMetadata::createFromObject($data->link));
Chris@0: 
Chris@0:       // Only render accessible links.
Chris@0:       if ($data->access instanceof AccessResultInterface && !$data->access->isAllowed()) {
Chris@0:         continue;
Chris@0:       }
Chris@0:       $element = [];
Chris@0: 
Chris@0:       // Set a variable for the <li> tag. Only set 'expanded' to true if the
Chris@0:       // link also has visible children within the current tree.
Chris@0:       $element['is_expanded'] = FALSE;
Chris@0:       $element['is_collapsed'] = FALSE;
Chris@0:       if ($data->hasChildren && !empty($data->subtree)) {
Chris@0:         $element['is_expanded'] = TRUE;
Chris@0:       }
Chris@0:       elseif ($data->hasChildren) {
Chris@0:         $element['is_collapsed'] = TRUE;
Chris@0:       }
Chris@0:       // Set a helper variable to indicate whether the link is in the active
Chris@0:       // trail.
Chris@0:       $element['in_active_trail'] = FALSE;
Chris@0:       if ($data->inActiveTrail) {
Chris@0:         $element['in_active_trail'] = TRUE;
Chris@0:       }
Chris@0: 
Chris@0:       // Note: links are rendered in the menu.html.twig template; and they
Chris@0:       // automatically bubble their associated cacheability metadata.
Chris@0:       $element['attributes'] = new Attribute();
Chris@0:       $element['title'] = $link->getTitle();
Chris@0:       $element['url'] = $link->getUrlObject();
Chris@0:       $element['url']->setOption('set_active_class', TRUE);
Chris@0:       $element['below'] = $data->subtree ? $this->buildItems($data->subtree, $tree_access_cacheability, $tree_link_cacheability) : [];
Chris@0:       if (isset($data->options)) {
Chris@0:         $element['url']->setOptions(NestedArray::mergeDeep($element['url']->getOptions(), $data->options));
Chris@0:       }
Chris@0:       $element['original_link'] = $link;
Chris@0:       // Index using the link's unique ID.
Chris@0:       $items[$link->getPluginId()] = $element;
Chris@0:     }
Chris@0: 
Chris@0:     return $items;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function maxDepth() {
Chris@0:     return $this->treeStorage->maxDepth();
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getSubtreeHeight($id) {
Chris@0:     return $this->treeStorage->getSubtreeHeight($id);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getExpanded($menu_name, array $parents) {
Chris@0:     return $this->treeStorage->getExpanded($menu_name, $parents);
Chris@0:   }
Chris@0: 
Chris@0: }