UnprocessableResponse

Namespace: RA.Utilities.Api.Response

The UnprocessableResponse class creates a standardized 422 Unprocessable Entity response. It derives from Response<T> with T = ErrorResult and is used when the request is syntactically valid but semantically impossible.

🎯 Purpose

Use UnprocessableResponse for business-rule violations that are not field validation errors — for example, cancelling an order that has already shipped.

• Standard envelope: ResponseCode = 422, ResponseType = ResponseType.Unprocessable, ResponseMessage = "Unprocessable entity."
• Optional payload: Result can be null or an ErrorResult describing the semantic failure.

Constructors

Constructor	Result	ResponseCode	ResponseMessage
UnprocessableResponse()	null	422	"Unprocessable entity."
UnprocessableResponse(int responseCode, string responseMessage = "")	null	responseCode	responseMessage ?? standard (the "" default is used as-is)
UnprocessableResponse(ErrorResult result)	result, or a default ErrorResult when null	422	"Unprocessable entity."
UnprocessableResponse(ErrorResult result, int responseCode, string responseMessage = "")	result, or a default ErrorResult when null	responseCode	responseMessage ?? standard (the "" default is used as-is)

ResponseType is always ResponseType.Unprocessable (JSON 13). When result is null, the constructor substitutes an ErrorResult with ErrorCode = "Unprocessable" and ErrorMessage = "Unprocessable entity.".

Usage

using Microsoft.AspNetCore.Mvc;
using RA.Utilities.Api.Response;

[HttpPost("{id}/cancel")]
public IActionResult CancelOrder(int id)
{
    var order = _service.GetById(id);
    if (order.Status == OrderStatus.Shipped)
    {
        return UnprocessableEntity(new UnprocessableResponse(new ErrorResult
        {
            ErrorCode = "ORDER_ALREADY_SHIPPED",
            ErrorMessage = "Cannot cancel an order that has already been shipped."
        }));
    }

    _service.Cancel(id);
    return Ok(new SuccessResponse<string>("Order cancelled."));
}

Example JSON Output

{
  "responseCode": 422,
  "responseType": 13,
  "responseMessage": "Unprocessable entity.",
  "result": {
    "errorCode": "ORDER_ALREADY_SHIPPED",
    "errorMessage": "Cannot cancel an order that has already been shipped."
  }
}

With JsonStringEnumConverter, responseType is "Unprocessable".