C#•2y ago

Return NotFound with details

Hello. I have a asp.net core Web API with controllers and I want to return for example a NotFound Error with a custom message attached, that I can then show to the user.

[HttpGet("{id:guid}", Name = "GetUrlaubsantragById")]
[ProducesResponseType(typeof(UrlaubsantragDto), StatusCodes.Status200OK)]
[ProducesResponseType(StatusCodes.Status404NotFound)]
[ProducesResponseType(StatusCodes.Status403Forbidden)]
[ProducesResponseType(StatusCodes.Status401Unauthorized)]
[ProducesResponseType(StatusCodes.Status500InternalServerError)]
public async Task<IActionResult> GetUrlaubsantragById([FromRoute] Guid id)
{
  var result = await _urlaubsantragService.GetUrlaubsantragAsync(id);
  if (result == null)
  {
    return NotFound();
  } 
  
  return Ok(result);
}

[HttpGet("{id:guid}", Name = "GetUrlaubsantragById")]
[ProducesResponseType(typeof(UrlaubsantragDto), StatusCodes.Status200OK)]
[ProducesResponseType(StatusCodes.Status404NotFound)]
[ProducesResponseType(StatusCodes.Status403Forbidden)]
[ProducesResponseType(StatusCodes.Status401Unauthorized)]
[ProducesResponseType(StatusCodes.Status500InternalServerError)]
public async Task<IActionResult> GetUrlaubsantragById([FromRoute] Guid id)
{
  var result = await _urlaubsantragService.GetUrlaubsantragAsync(id);
  if (result == null)
  {
    return NotFound();
  } 
  
  return Ok(result);
}

This for example creates a problem, so the format that I want:

{
  "type": "https://tools.ietf.org/html/rfc7231#section-6.5.4",
  "title": "Not Found",
  "status": 404,
  "traceId": "00-cb37e3ba34b597ba19e7cf39665feb58-73e25a81a8b6a327-00"
}

{
  "type": "https://tools.ietf.org/html/rfc7231#section-6.5.4",
  "title": "Not Found",
  "status": 404,
  "traceId": "00-cb37e3ba34b597ba19e7cf39665feb58-73e25a81a8b6a327-00"
}

But when I add a message to the ActionResult I only get a text/plain message:

public async Task<IActionResult> GetUrlaubsantragById([FromRoute] Guid id)
{
  var result = await _urlaubsantragService.GetUrlaubsantragAsync(id);
  if (result == null)
  {
    return NotFound("My custom error message");
  } 
    
  return Ok(result);
}

public async Task<IActionResult> GetUrlaubsantragById([FromRoute] Guid id)
{
  var result = await _urlaubsantragService.GetUrlaubsantragAsync(id);
  if (result == null)
  {
    return NotFound("My custom error message");
  } 
    
  return Ok(result);
}

Does someone have an idea, what is going on?

8 Replies

JakenVeina•2y ago

what's going on is that you told your API method to return a string, so that's what it did

Jan KrügerOP•2y ago

Okay, but is there a way to convert that into a problem details?

JakenVeina•2y ago

https://learn.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.mvc.problemdetails?view=aspnetcore-7.0

ProblemDetails Class (Microsoft.AspNetCore.Mvc)

A machine-readable format for specifying errors in HTTP API responses based on https://tools.ietf.org/html/rfc7807.

Jan KrügerOP•2y ago

So I'd have to create an instance of that and then return that? But it feels like a lot of boiler code to add that at every controller and for every possible response code. I just wanted a consistent error response format to for all errors, with optional details

JakenVeina•2y ago

https://learn.microsoft.com/en-us/aspnet/core/web-api/handle-errors?view=aspnetcore-7.0#client-error-response

Handle errors in ASP.NET Core web APIs

Learn about error handling with ASP.NET Core web APIs.

Jan KrügerOP•2y ago

Thank you for the resources, I'll take a look at that 🙂

JakenVeina•2y ago

I think some of that latter section, with regards to services.AddProblemDetails() is only applicable to ASP.NET Core 7+. if thay matters on your end

Jan KrügerOP•2y ago

That is fine, tho I see this:

The following code configures the app to generate a problem details response for all HTTP client and server error responses that don't have a body content yet:

Do have an Idea how I could still attach details? I could go ahead and create exceptions for each status code, I guess. But this still feels like a lot of boilerplate to me. And its imho something very basic so I thought there might a already build solution for this

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Return NotFound with details