class ContextualLinkManager

class ContextualLinkManager extends DefaultPluginManager implements ContextualLinkManagerInterface {
    
    /**
     * Provides default values for a contextual link definition.
     *
     * @var array
     */
    protected $defaults = [
        // (required) The name of the route to link to.
'route_name' => '',
        // (required) The contextual links group.
'group' => '',
        // The static title text for the link.
'title' => '',
        // The default link options.
'options' => [],
        // The weight of the link.
'weight' => NULL,
        // Default class for contextual link implementations.
'class' => '\\Drupal\\Core\\Menu\\ContextualLinkDefault',
        // The plugin id. Set by the plugin system based on the top-level YAML key.
'id' => '',
    ];
    
    /**
     * A controller resolver object.
     *
     * @var \Symfony\Component\HttpKernel\Controller\ControllerResolverInterface
     */
    protected $controllerResolver;
    
    /**
     * The access manager.
     *
     * @var \Drupal\Core\Access\AccessManagerInterface
     */
    protected $accessManager;
    
    /**
     * The current user.
     *
     * @var \Drupal\Core\Session\AccountInterface
     */
    protected $account;
    
    /**
     * The request stack.
     *
     * @var \Symfony\Component\HttpFoundation\RequestStack
     */
    protected $requestStack;
    
    /**
     * A static cache of all the contextual link plugins by group name.
     *
     * @var array
     */
    protected $pluginsByGroup;
    
    /**
     * Constructs a new ContextualLinkManager instance.
     *
     * @param \Drupal\Core\Controller\ControllerResolverInterface $controller_resolver
     *   The controller resolver.
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     *   The module handler.
     * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
     *   The cache backend.
     * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
     *   The language manager.
     * @param \Drupal\Core\Access\AccessManagerInterface $access_manager
     *   The access manager.
     * @param \Drupal\Core\Session\AccountInterface $account
     *   The current user.
     * @param \Symfony\Component\HttpFoundation\RequestStack $request_stack
     *   The request stack.
     */
    public function __construct(ControllerResolverInterface $controller_resolver, ModuleHandlerInterface $module_handler, CacheBackendInterface $cache_backend, LanguageManagerInterface $language_manager, AccessManagerInterface $access_manager, AccountInterface $account, RequestStack $request_stack) {
        $this->factory = new ContainerFactory($this, '\\Drupal\\Core\\Menu\\ContextualLinkInterface');
        $this->controllerResolver = $controller_resolver;
        $this->accessManager = $access_manager;
        $this->account = $account;
        $this->moduleHandler = $module_handler;
        $this->requestStack = $request_stack;
        $this->alterInfo('contextual_links_plugins');
        $this->setCacheBackend($cache_backend, 'contextual_links_plugins:' . $language_manager->getCurrentLanguage()
            ->getId(), [
            'contextual_links_plugins',
        ]);
    }
    
    /**
     * {@inheritdoc}
     */
    protected function getDiscovery() {
        if (!isset($this->discovery)) {
            $yaml_discovery = new YamlDiscovery('links.contextual', $this->moduleHandler
                ->getModuleDirectories());
            $yaml_discovery->addTranslatableProperty('title', 'title_context');
            $this->discovery = new ContainerDerivativeDiscoveryDecorator($yaml_discovery);
        }
        return $this->discovery;
    }
    
    /**
     * {@inheritdoc}
     */
    public function processDefinition(&$definition, $plugin_id) {
        parent::processDefinition($definition, $plugin_id);
        // If there is no route name, this is a broken definition.
        if (empty($definition['route_name'])) {
            throw new PluginException(sprintf('Contextual link plugin (%s) definition must include "route_name".', $plugin_id));
        }
        // If there is no group name, this is a broken definition.
        if (empty($definition['group'])) {
            throw new PluginException(sprintf('Contextual link plugin (%s) definition must include "group".', $plugin_id));
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function getContextualLinkPluginsByGroup($group_name) {
        if (isset($this->pluginsByGroup[$group_name])) {
            $contextual_links = $this->pluginsByGroup[$group_name];
        }
        elseif ($cache = $this->cacheBackend
            ->get($this->cacheKey . ':' . $group_name)) {
            $contextual_links = $cache->data;
            $this->pluginsByGroup[$group_name] = $contextual_links;
        }
        else {
            $contextual_links = [];
            foreach ($this->getDefinitions() as $plugin_id => $plugin_definition) {
                if ($plugin_definition['group'] == $group_name) {
                    $contextual_links[$plugin_id] = $plugin_definition;
                }
            }
            $this->cacheBackend
                ->set($this->cacheKey . ':' . $group_name, $contextual_links);
            $this->pluginsByGroup[$group_name] = $contextual_links;
        }
        return $contextual_links;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getContextualLinksArrayByGroup($group_name, array $route_parameters, array $metadata = []) {
        $links = [];
        $request = $this->requestStack
            ->getCurrentRequest();
        foreach ($this->getContextualLinkPluginsByGroup($group_name) as $plugin_id => $plugin_definition) {
            
            /** @var $plugin \Drupal\Core\Menu\ContextualLinkInterface */
            $plugin = $this->createInstance($plugin_id);
            $route_name = $plugin->getRouteName();
            // Check access.
            if (!$this->accessManager
                ->checkNamedRoute($route_name, $route_parameters, $this->account)) {
                continue;
            }
            $links[$plugin_id] = [
                'route_name' => $route_name,
                'route_parameters' => $route_parameters,
                'title' => $plugin->getTitle($request),
                'weight' => $plugin->getWeight(),
                'localized_options' => $plugin->getOptions(),
                'metadata' => $metadata,
            ];
        }
        $this->moduleHandler
            ->alter('contextual_links', $links, $group_name, $route_parameters);
        return $links;
    }

}