Currently when the validation type failed (here I am using data annotation ValidationAttribute), its content-type is application/json.

How do I configure it to return its content-type as application/problem json while maintaining the error details?

Here is my controller in NET 6 Web Api project.

[Route("api/[controller]")]
[ApiController]
public class AccountController : ControllerBase
{
    private readonly IAccountService _accountService;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="accountService"></param>
    public AccountController(IAccountService accountService)
    {
        _accountService = accountService;
    }

    [HttpGet]
    [Route("IsAccountClosed/{nric}")]
    [ProducesResponseType(StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status204NoContent)]
    [ProducesResponseType(StatusCodes.Status422UnprocessableEntity)]
    [ProducesResponseType(StatusCodes.Status404NotFound)]
    [ProducesResponseType(StatusCodes.Status500InternalServerError)]
    public async Task<ActionResult> IsAccountClosed([Required] string nric)
    {
        if (!ModelState.IsValid) {
            return UnprocessableEntity(ModelState);
        }     
    }
}

I tried to remove the ModelState parameter in UnprocessableEntity to become return UnprocessableEntity();

But I can't see the data annotation validation details.

Is it because of my ValidationFilterAttribute?

public class ValidationFilterAttribute : IActionFilter
{
    public void OnActionExecuting(ActionExecutingContext context)
    {
        if (!context.ModelState.IsValid)
        {
           context.Result = new UnprocessableEntityObjectResult(context.ModelState);                
        }
    }

    public void OnActionExecuted(ActionExecutedContext context) { }
}

CodePudding user response：

is marked as required. so we have to pass always something

so I tried with space and call the API

and i am getting correct response with no change in your code.

check the response content type and also annotation validation detail is mentioned.

CodePudding user response：

You don't need that custom filter.
The ApiControllerAttribute triggers ModelState validation automatically.

From the documentation

The [ApiController] attribute makes model validation errors automatically trigger an HTTP 400 response. Consequently, the following code is unnecessary in an action method:

if (!ModelState.IsValid)
{
    return BadRequest(ModelState);
}

So just remove that custom filter and ModelState.IsValid call.