Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\system\Plugin\Block;
Chris@0: 
Chris@0: use Drupal\Core\Block\BlockBase;
Chris@0: use Drupal\Core\Cache\Cache;
Chris@0: use Drupal\Core\Form\FormStateInterface;
Chris@18: use Drupal\Core\Menu\MenuActiveTrailInterface;
Chris@0: use Drupal\Core\Menu\MenuLinkTreeInterface;
Chris@18: use Drupal\Core\Menu\MenuTreeParameters;
Chris@0: use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
Chris@0: use Symfony\Component\DependencyInjection\ContainerInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Provides a generic Menu block.
Chris@0:  *
Chris@0:  * @Block(
Chris@0:  *   id = "system_menu_block",
Chris@0:  *   admin_label = @Translation("Menu"),
Chris@0:  *   category = @Translation("Menus"),
Chris@14:  *   deriver = "Drupal\system\Plugin\Derivative\SystemMenuBlock",
Chris@14:  *   forms = {
Chris@14:  *     "settings_tray" = "\Drupal\system\Form\SystemMenuOffCanvasForm",
Chris@14:  *   },
Chris@0:  * )
Chris@0:  */
Chris@0: class SystemMenuBlock extends BlockBase implements ContainerFactoryPluginInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The menu link tree service.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Menu\MenuLinkTreeInterface
Chris@0:    */
Chris@0:   protected $menuTree;
Chris@0: 
Chris@0:   /**
Chris@18:    * The active menu trail service.
Chris@18:    *
Chris@18:    * @var \Drupal\Core\Menu\MenuActiveTrailInterface
Chris@18:    */
Chris@18:   protected $menuActiveTrail;
Chris@18: 
Chris@18:   /**
Chris@0:    * Constructs a new SystemMenuBlock.
Chris@0:    *
Chris@0:    * @param array $configuration
Chris@0:    *   A configuration array containing information about the plugin instance.
Chris@0:    * @param string $plugin_id
Chris@0:    *   The plugin_id for the plugin instance.
Chris@0:    * @param array $plugin_definition
Chris@0:    *   The plugin implementation definition.
Chris@0:    * @param \Drupal\Core\Menu\MenuLinkTreeInterface $menu_tree
Chris@0:    *   The menu tree service.
Chris@18:    * @param \Drupal\Core\Menu\MenuActiveTrailInterface $menu_active_trail
Chris@18:    *   The active menu trail service.
Chris@0:    */
Chris@18:   public function __construct(array $configuration, $plugin_id, $plugin_definition, MenuLinkTreeInterface $menu_tree, MenuActiveTrailInterface $menu_active_trail = NULL) {
Chris@0:     parent::__construct($configuration, $plugin_id, $plugin_definition);
Chris@0:     $this->menuTree = $menu_tree;
Chris@18:     if ($menu_active_trail === NULL) {
Chris@18:       @trigger_error('The menu.active_trail service must be passed to SystemMenuBlock::__construct(), it is required before Drupal 9.0.0. See https://www.drupal.org/node/2669550.', E_USER_DEPRECATED);
Chris@18:       $menu_active_trail = \Drupal::service('menu.active_trail');
Chris@18:     }
Chris@18:     $this->menuActiveTrail = $menu_active_trail;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
Chris@0:     return new static(
Chris@0:       $configuration,
Chris@0:       $plugin_id,
Chris@0:       $plugin_definition,
Chris@18:       $container->get('menu.link_tree'),
Chris@18:       $container->get('menu.active_trail')
Chris@0:     );
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function blockForm($form, FormStateInterface $form_state) {
Chris@0:     $config = $this->configuration;
Chris@0: 
Chris@0:     $defaults = $this->defaultConfiguration();
Chris@0:     $form['menu_levels'] = [
Chris@0:       '#type' => 'details',
Chris@0:       '#title' => $this->t('Menu levels'),
Chris@0:       // Open if not set to defaults.
Chris@0:       '#open' => $defaults['level'] !== $config['level'] || $defaults['depth'] !== $config['depth'],
Chris@0:       '#process' => [[get_class(), 'processMenuLevelParents']],
Chris@0:     ];
Chris@0: 
Chris@0:     $options = range(0, $this->menuTree->maxDepth());
Chris@0:     unset($options[0]);
Chris@0: 
Chris@0:     $form['menu_levels']['level'] = [
Chris@0:       '#type' => 'select',
Chris@0:       '#title' => $this->t('Initial visibility level'),
Chris@0:       '#default_value' => $config['level'],
Chris@0:       '#options' => $options,
Chris@0:       '#description' => $this->t('The menu is only visible if the menu item for the current page is at this level or below it. Use level 1 to always display this menu.'),
Chris@0:       '#required' => TRUE,
Chris@0:     ];
Chris@0: 
Chris@0:     $options[0] = $this->t('Unlimited');
Chris@0: 
Chris@0:     $form['menu_levels']['depth'] = [
Chris@0:       '#type' => 'select',
Chris@0:       '#title' => $this->t('Number of levels to display'),
Chris@0:       '#default_value' => $config['depth'],
Chris@0:       '#options' => $options,
Chris@0:       '#description' => $this->t('This maximum number includes the initial level.'),
Chris@0:       '#required' => TRUE,
Chris@0:     ];
Chris@0: 
Chris@18:     $form['menu_levels']['expand_all_items'] = [
Chris@18:       '#type' => 'checkbox',
Chris@18:       '#title' => $this->t('Expand all menu items'),
Chris@18:       '#default_value' => !empty($config['expand_all_items']),
Chris@18:       '#description' => $this->t('Override the option found on each menu link used for expanding children and instead display the whole menu tree as expanded.'),
Chris@18:     ];
Chris@18: 
Chris@0:     return $form;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Form API callback: Processes the menu_levels field element.
Chris@0:    *
Chris@0:    * Adjusts the #parents of menu_levels to save its children at the top level.
Chris@0:    */
Chris@0:   public static function processMenuLevelParents(&$element, FormStateInterface $form_state, &$complete_form) {
Chris@0:     array_pop($element['#parents']);
Chris@0:     return $element;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function blockSubmit($form, FormStateInterface $form_state) {
Chris@0:     $this->configuration['level'] = $form_state->getValue('level');
Chris@0:     $this->configuration['depth'] = $form_state->getValue('depth');
Chris@18:     $this->configuration['expand_all_items'] = $form_state->getValue('expand_all_items');
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function build() {
Chris@0:     $menu_name = $this->getDerivativeId();
Chris@18:     if ($this->configuration['expand_all_items']) {
Chris@18:       $parameters = new MenuTreeParameters();
Chris@18:       $active_trail = $this->menuActiveTrail->getActiveTrailIds($menu_name);
Chris@18:       $parameters->setActiveTrail($active_trail);
Chris@18:     }
Chris@18:     else {
Chris@18:       $parameters = $this->menuTree->getCurrentRouteMenuTreeParameters($menu_name);
Chris@18:     }
Chris@0: 
Chris@0:     // Adjust the menu tree parameters based on the block's configuration.
Chris@0:     $level = $this->configuration['level'];
Chris@0:     $depth = $this->configuration['depth'];
Chris@0:     $parameters->setMinDepth($level);
Chris@0:     // When the depth is configured to zero, there is no depth limit. When depth
Chris@0:     // is non-zero, it indicates the number of levels that must be displayed.
Chris@0:     // Hence this is a relative depth that we must convert to an actual
Chris@0:     // (absolute) depth, that may never exceed the maximum depth.
Chris@0:     if ($depth > 0) {
Chris@0:       $parameters->setMaxDepth(min($level + $depth - 1, $this->menuTree->maxDepth()));
Chris@0:     }
Chris@0: 
Chris@0:     // For menu blocks with start level greater than 1, only show menu items
Chris@0:     // from the current active trail. Adjust the root according to the current
Chris@0:     // position in the menu in order to determine if we can show the subtree.
Chris@0:     if ($level > 1) {
Chris@0:       if (count($parameters->activeTrail) >= $level) {
Chris@0:         // Active trail array is child-first. Reverse it, and pull the new menu
Chris@0:         // root based on the parent of the configured start level.
Chris@0:         $menu_trail_ids = array_reverse(array_values($parameters->activeTrail));
Chris@0:         $menu_root = $menu_trail_ids[$level - 1];
Chris@0:         $parameters->setRoot($menu_root)->setMinDepth(1);
Chris@0:         if ($depth > 0) {
Chris@0:           $parameters->setMaxDepth(min($level - 1 + $depth - 1, $this->menuTree->maxDepth()));
Chris@0:         }
Chris@0:       }
Chris@0:       else {
Chris@0:         return [];
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     $tree = $this->menuTree->load($menu_name, $parameters);
Chris@0:     $manipulators = [
Chris@0:       ['callable' => 'menu.default_tree_manipulators:checkAccess'],
Chris@0:       ['callable' => 'menu.default_tree_manipulators:generateIndexAndSort'],
Chris@0:     ];
Chris@0:     $tree = $this->menuTree->transform($tree, $manipulators);
Chris@0:     return $this->menuTree->build($tree);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function defaultConfiguration() {
Chris@0:     return [
Chris@0:       'level' => 1,
Chris@0:       'depth' => 0,
Chris@18:       'expand_all_items' => FALSE,
Chris@0:     ];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getCacheTags() {
Chris@0:     // Even when the menu block renders to the empty string for a user, we want
Chris@0:     // the cache tag for this menu to be set: whenever the menu is changed, this
Chris@0:     // menu block must also be re-rendered for that user, because maybe a menu
Chris@0:     // link that is accessible for that user has been added.
Chris@0:     $cache_tags = parent::getCacheTags();
Chris@0:     $cache_tags[] = 'config:system.menu.' . $this->getDerivativeId();
Chris@0:     return $cache_tags;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getCacheContexts() {
Chris@0:     // ::build() uses MenuLinkTreeInterface::getCurrentRouteMenuTreeParameters()
Chris@0:     // to generate menu tree parameters, and those take the active menu trail
Chris@0:     // into account. Therefore, we must vary the rendered menu by the active
Chris@0:     // trail of the rendered menu.
Chris@0:     // Additional cache contexts, e.g. those that determine link text or
Chris@0:     // accessibility of a menu, will be bubbled automatically.
Chris@0:     $menu_name = $this->getDerivativeId();
Chris@0:     return Cache::mergeContexts(parent::getCacheContexts(), ['route.menu_active_trails:' . $menu_name]);
Chris@0:   }
Chris@0: 
Chris@0: }