MenuLinksetRoutes.php

<?php

namespace Drupal\system\Routing;

use Drupal\Core\Config\ConfigCrudEvent;
use Drupal\Core\Config\ConfigEvents;
use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\Routing\Route;
use Drupal\Core\Config\ConfigFactoryInterface;
use Drupal\Core\Routing\RouteSubscriberBase;
use Drupal\Core\Routing\RouteBuilderInterface;
use Symfony\Component\Routing\RouteCollection;

/**
 * Dynamically defines routes for menu linkset endpoints.
 */
class MenuLinksetRoutes extends RouteSubscriberBase implements ContainerInjectionInterface {
    
    /**
     * An array of enabled authentication provider IDs.
     *
     * @var string[]
     */
    protected readonly array $providerIds;
    
    /**
     * EventSubscriber constructor.
     *
     * @param string[] $authenticationProviders
     *   An array of authentication providers, keyed by ID.
     * @param \Drupal\Core\Config\ConfigFactoryInterface $configFactory
     *   The config factory.
     * @param \Drupal\Core\Routing\RouteBuilderInterface $routeBuilder
     *   The route builder.
     */
    public function __construct(array $authenticationProviders, ConfigFactoryInterface $configFactory, RouteBuilderInterface $routeBuilder) {
        $this->providerIds = array_keys($authenticationProviders);
    }
    
    /**
     * Alter routes.
     *
     * If the endpoint is configured to be enabled, dynamically enable all
     * authentication providers on this module's routes since they cannot be known
     * in advance.
     *
     * @param \Symfony\Component\Routing\RouteCollection $collection
     *   A collection of routes.
     */
    public function alterRoutes(RouteCollection $collection) {
        if ($this->configFactory
            ->get('system.feature_flags')
            ->get('linkset_endpoint')) {
            $collection->get('system.menu.linkset')
                ->setOption('_auth', $this->providerIds);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function onConfigSave(ConfigCrudEvent $event) {
        $saved_config = $event->getConfig();
        if ($saved_config->getName() === 'system.feature_flags' && $event->isChanged('linkset_endpoint')) {
            $this->routeBuilder
                ->setRebuildNeeded();
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public static function getSubscribedEvents() : array {
        $events = parent::getSubscribedEvents();
        // Run after the route alter event subscriber.
        $events[ConfigEvents::SAVE][] = [
            'onConfigSave',
            0,
        ];
        return $events;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->getParameter('authentication_providers'), $container->get('config.factory'), $container->get('router.builder'));
    }
    
    /**
     * Returns an array of route objects.
     *
     * @return \Symfony\Component\Routing\Route[]
     *   An array of route objects.
     */
    public function routes() {
        $routes = [];
        // Only enable linkset routes if the related config option is enabled.
        if ($this->configFactory
            ->get('system.feature_flags')
            ->get('linkset_endpoint')) {
            $routes['system.menu.linkset'] = new Route('/system/menu/{menu}/linkset', [
                '_controller' => 'Drupal\\system\\Controller\\LinksetController::process',
            ], [
                '_access' => 'TRUE',
            ], [
                'parameters' => [
                    'menu' => [
                        'type' => 'entity:menu',
                    ],
                ],
            ]);
        }
        return $routes;
    }

}