EntityBundleAccessCheck.php

<?php

namespace Drupal\Core\Entity;

use Drupal\Core\Access\AccessResult;
use Drupal\Core\Routing\Access\AccessInterface;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Session\AccountInterface;
use Symfony\Component\Routing\Route;

/**
 * Provides an entity bundle checker for the _entity_bundles route requirement.
 */
class EntityBundleAccessCheck implements AccessInterface {
    
    /**
     * Checks entity bundle match based on the _entity_bundles route requirement.
     *
     * @code
     * example.route:
     *   path: foo/{example_entity_type}/{other_parameter}
     *   requirements:
     *     _entity_bundles: 'example_entity_type:example_bundle|other_example_bundle'
     * @endcode
     *
     * @param \Symfony\Component\Routing\Route $route
     *   The route to check against.
     * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
     *   The parametrized route.
     * @param \Drupal\Core\Session\AccountInterface $account
     *   The currently logged in account.
     *
     * @return \Drupal\Core\Access\AccessResultInterface
     *   The access result.
     */
    public function access(Route $route, RouteMatchInterface $route_match, AccountInterface $account) {
        if ($route->hasRequirement('_entity_bundles')) {
            list($entity_type, $bundle_definition) = explode(':', $route->getRequirement('_entity_bundles'));
            $bundles = explode('|', $bundle_definition);
            $parameters = $route_match->getParameters();
            if ($parameters->has($entity_type)) {
                $entity = $parameters->get($entity_type);
                if ($entity instanceof EntityInterface && in_array($entity->bundle(), $bundles, TRUE)) {
                    return AccessResult::allowed()->addCacheableDependency($entity);
                }
            }
        }
        return AccessResult::neutral('The entity bundle does not match the route _entity_bundles requirement.');
    }

}