In .NET Core Web API, you can customize the response for model validation errors by implementing a custom ValidationProblemDetails
class and overriding the OnSerialize
method. This allows you to remove specific fields like "type," "title," and "traceId" from the response.
Here's how you can achieve this:
- Create a custom
ValidationProblemDetails
class that inherits from the built-inValidationProblemDetails
class:
using Microsoft.AspNetCore.Mvc;
public class CustomValidationProblemDetails : ValidationProblemDetails
{
// Override the OnSerialize method to remove unwanted fields
public override void OnSerialize(Microsoft.AspNetCore.Http.Json.JsonElementWriter writer)
{
// Remove the "type," "title," and "traceId" fields from the response
writer.WriteStartObject();
writer.WriteEndObject();
}
}
In your controller, when you want to return a model validation error, use the CustomValidationProblemDetails
class:
[ApiController]
public class YourController : ControllerBase
{
[HttpPost]
public IActionResult SomeAction([FromBody] YourModel model)
{
if (!ModelState.IsValid)
{
// Create a new instance of the custom validation problem details
var problemDetails = new CustomValidationProblemDetails
{
Status = 400,
Title = "One or more validation errors occurred.",
// Populate the errors dictionary based on your model's validation errors
Errors = ModelState.ToDictionary(
kvp => kvp.Key,
kvp => kvp.Value.Errors.Select(e => e.ErrorMessage).ToArray()
)
};
// Return the custom validation problem details
return new BadRequestObjectResult(problemDetails);
}
// Your regular code here for successful processing
return Ok();
}
}
In this example, we've created a custom class CustomValidationProblemDetails
that inherits from ValidationProblemDetails
and overrides the OnSerialize
method to remove the unwanted fields from the response. Then, in the controller, we use this custom class to create and return the response for model validation errors.
By using this approach, you can control the fields included in the response for model validation errors and remove the "type," "title," and "traceId" fields as you desired.