Question

I have strange issue. ModelState has error. But I don`t have a rule for it. No filters, no rules in validator file.

My code. ViewModel:

[Validator(typeof(TestValidation))]
public class PayerPayRateViewModel 
{

    public int TestId { get; set; }

    public bool AllServices { get; set; }

    public int ParentEntityId { get; set; }
}

Validator

 public class TestValidation : BaseEntityRepositoryValidator<Core.Domain.Model.Entities.Payer, PayerPayRateViewModel>
{
    public TestValidation()
    {
        RuleFor(x => x.ParentEntityId).Must(CheckUniqueService);
    }

    protected bool CheckUniqueService(PayerPayRateViewModel model, int value)
    {
        if (model.AllServices)
        {
            return true;
        }

        return false;          
    }      
}

And if I have TestId with value 0 I get “TestId: Field is required“.

When I remove validation attribute from Viewmodel class I get “A value is required.” error.

Why it happens?

Answer 1

Because you are attempting to bind an empty string to a non-nullable type. If you want this to happen use nullable types:

[Validator(typeof(TestValidation))]
public class PayerPayRateViewModel 
{
    public int? TestId { get; set; }

    public bool AllServices { get; set; }

    public int ParentEntityId { get; set; }
}

By default there’s an implicit Required attribute applied to all non-nullable types (think integers, datetimes, decimals, …).

By the way you could disable this default behavior:

DataAnnotationsModelValidatorProvider
    .AddImplicitRequiredAttributeForValueTypes = false;