class EntityCreateAccessCheck

class EntityCreateAccessCheck implements AccessInterface {
  
  /**
   * The entity type manager service.
   *
   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
   */
  protected $entityTypeManager;
  
  /**
   * The key used by the routing requirement.
   *
   * @var string
   */
  protected $requirementsKey = '_entity_create_access';
  
  /**
   * Constructs an EntityCreateAccessCheck object.
   *
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
   *   The entity type manager service.
   */
  public function __construct(EntityTypeManagerInterface $entity_type_manager) {
    $this->entityTypeManager = $entity_type_manager;
  }
  
  /**
   * Checks access to create the entity type and bundle for the given route.
   *
   * @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 $account) {
    [$entity_type, $bundle] = explode(':', $route->getRequirement($this->requirementsKey) . ':');
    // The bundle argument can contain request argument placeholders like
    // {name}, loop over the raw variables and attempt to replace them in the
    // bundle name. If a placeholder does not exist, it won't get replaced.
    if ($bundle && strpos($bundle, '{') !== FALSE) {
      foreach ($route_match->getRawParameters()
        ->all() as $name => $value) {
        $bundle = str_replace('{' . $name . '}', $value, $bundle);
      }
      // If we were unable to replace all placeholders, deny access.
      if (strpos($bundle, '{') !== FALSE) {
        return AccessResult::neutral(sprintf("Could not find '%s' request argument, therefore cannot check create access.", $bundle));
      }
    }
    return $this->entityTypeManager
      ->getAccessControlHandler($entity_type)
      ->createAccess($bundle, $account, [], TRUE);
  }

}