How to localize exception message for Json deserialization? An invalid parameter was passed when req-CodePudding

My development environment is.Net7 WebApi (out of the box)

Below is the relevant code. DataAnnotations I have implemented localization.

using System.ComponentModel.DataAnnotations;

namespace WebApi.Dtos
{
    public class UserRegistrationDto
    {
        [Required(ErrorMessage = "UserNameRequiredError")]
        [MinLength(6, ErrorMessage = "UserNameMinLengthError")]
        [MaxLength(30, ErrorMessage = "UserNameMaxLengthError")]
        public required string UserName { get; set; }

        [Required(ErrorMessage = "PasswordRequiredError")]
        public required string Password { get; set; }
    }
}

[HttpPost]
public async Task<IActionResult> RegisterUser([FromBody] UserRegistrationDto userRegistration)
{
    return Ok(1);
    // IdentityResult userResult = await _userManager.CreateAsync(new IdentityUser { UserName = userRegistration.UserName }, userRegistration.Password);

    // return userResult.Succeeded ? StatusCode(201) : BadRequest(userResult);
}

When the request body is invalid JSON.

curl -X 'POST' \
  'https://localhost:7177/Authenticate/RegisterUser' \
  -H 'accept: */*' \
  -H 'Api-Version: 1.0' \
  -H 'Content-Type: application/json' \
  -d '{}'

{
    "$": [
        "JSON deserialization for type 'WebApi.Dtos.UserRegistrationDto' was missing required properties, including the following: userName, password"
    ],
    "userRegistration": [
        "The userRegistration field is required."
    ]
}

When the request body is Empty.

curl -X 'POST' \
  'https://localhost:7177/Authenticate/RegisterUser' \
  -H 'accept: */*' \
  -H 'Api-Version: 1.0' \
  -H 'Content-Type: application/json' \
  -d ''

{
    "": [
        "The userRegistration field is required."
    ]
}

It throws exception information before binding to DTO, can this exception information be localized? If not, is it possible to capture this information for secondary processing, such as returning a fixed JSON format?

I've tried this in the Program.cs entry file, but it's not ideal.

.ConfigureApiBehaviorOptions(options =>
{
    options.SuppressModelStateInvalidFilter = false;
    options.InvalidModelStateResponseFactory = context =>
    {
        bool knownExceptions = context.ModelState.Values.SelectMany(x => x.Errors).Where(x => x.Exception is JsonException || (x.Exception is null && String.IsNullOrWhiteSpace(x.ErrorMessage) == false)).Count() > 0;
        if (knownExceptions)
        {
            return new BadRequestObjectResult(new { state = false, message = localizer["InvalidParameterError"].Value });
        }
        // ...
        return new BadRequestObjectResult(context.ModelState);
    };
})

I have also tried this method, but I can’t capture the exception information that failed when binding DTO alone. They will appear together with the ErrorMessage exception information in DTO like the above writing method.

.AddControllers(options =>
{
    // options.Filters.Add(...);
    // options.ModelBindingMessageProvider // This doesn't work either, it seems to support [FromForm]
})

Back to the topic, can it be localized? Or there is something wrong with the code. I just learned .Net not long ago. Most of the information I learned came from search engines and official documents. Thanks in advance.

CodePudding user response：

Use the following method.

.AddControllers(options =>
{
    // options.ModelBindingMessageProvider.Set...
})

It seems that the exception of JSON deserialization caused by passing invalid parameters can only be eliminated on the client side. So far it seems I haven't found a localization for this exception, but it's not very important to me at the moment. Thanks @XinranShen for helping point me in the right direction.