Implicit conversion for JSON

ArticleControllerCreate.scala

implicit val ArticleCreate = Json.reads[ArticleForCreation]  
  
  def create = IsAuthenticated { username =>
    implicit request =>
      userIdOpt.map { userId =>
        request.body.asJson.map { json =>
          json.validate[ArticleForCreation].fold(
            invalid => {
              BadRequest(Json.toJson(Map("error" -> invalid.head.toString)))
            },
            valid => {
              Articles.create(userId, valid) match {
                case Success(a) => {
                 Ok(Json.toJson(a)) 
                }
                case Failure(e) => BadRequest(Json.toJson(Map("error" -> e.getMessage())))
              }
            })
        }.getOrElse(BadRequest(Json.toJson(
          Map("status" -> "error request.body", "message" -> "Not Json"))))
      }.getOrElse(BadRequest(Json.toJson(
        Map("status" -> "error userID", "message" -> "Not Json"))))
  }