Include a valid field if ModelState state is Invalid

Question

In ASP.NET Web API I want to include a valid field when returning errors to the caller.

public class User 
{
    [Required(ErrorMessage = "ThirdPartyID is required!")]
    public int ThirdPartyID { get; set; }
    [Required(ErrorMessage = "Firstname is required!")]
    public string Firstname { get; set; }
    [Required(ErrorMessage = "Lastname is required!")]
    public string Lastname { get; set; }
}

When the caller posts a user with the ThirdParyID set, and the Firstname set, but without the Lastname, I want to add the ThirdPartyID to the response. I am using the below for Model Validation.

public class ModelValidationFilterAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(HttpActionContext actionContext)
    {
        if (actionContext.ModelState.IsValid == false)
        {
            actionContext.Response = actionContext.Request.CreateErrorResponse(HttpStatusCode.BadRequest, actionContext.ModelState);
        }
    }
}

Is there something I can set on the User to indicate that the ThirdPartyID should always be included in the returned error messages?

I'm having trouble understanding your business requirement. Is ThirdPartyId required or isn't it? — Youssef Moussaoui, Feb 05 '13 at 10:56
We can say it is. But I still want to return it in the error message even if it is sent by the consumer of the API during the post. — tom, Feb 05 '13 at 15:00

score 0 · Answer 1 · answered Feb 04 '13 at 17:55

0

You can use the ModelState.AddModelError method.

ModelState.AddModelError("VariableName", "Error Message");

answered Feb 04 '13 at 17:55

Pat Burke

580
4
13

That's fine if I'm doing validation inside the controller, but I want to do it in ModelValidationFilterAttribute : ActionFilterAttribute and for different models the valid field I want to return will vary. – tom Feb 04 '13 at 17:57

Include a valid field if ModelState state is Invalid

1 Answers1