FetchNotifications.scala

object FetchNotifications 
  extends ActionTransformer[AuthRequest, NotificationRequest] {

  def transform[A](request: AuthRequest[A]) = Future {
    request.user.map { user => 
      NotificationRequest[A](Some(user), findNotificationsByUser(user), request)
    } getOrElse {
      NotificationRequest[A](None, None, request)
    }
  }

}

case class NotificationRequest[A](
  val user: Option[User], 
  val notifications: Option[List[Notification]], 
  request: Request[A]
) extends WrappedRequest(request)