How to get a required error message for radio buttons using FluentValidation

Question

I am using ASP.NET MVC 4 and the latest FluentValidation.

I am struggling to get my radio buttons to validate. When I click the submit button I need a selection in the radio button list.

In my view I have the following:

@model MyProject.ViewModels.Servers.ServicesViewModel
@Html.ValidationMessageFor(x => x.ComponentTypeId)
@foreach (var componentType in Model.ComponentTypes)
{
     <div>
          @Html.RadioButtonFor(x => x.ComponentTypeId, componentType.Id, new { id = "emp" + componentType.Id })
          @Html.Label("emp" + componentType.Id, componentType.Name)
     </div>
}

My ComponentType class:

public class ComponentType : IEntity
{
     public int Id { get; set; }

     public string Name { get; set; }
}

Part of my action method where I set the properties of my view model:

ServicesViewModel viewModel = new ServicesViewModel
{
     ComponentTypes = componentTypeRepository.FindAll(),
     Domains = domainRepository.FindAll()
};

My view model:

[Validator(typeof(ServicesViewModelValidator))]
public class ServicesViewModel
{
     public int ComponentTypeId { get; set; }

     public IEnumerable<ComponentType> ComponentTypes { get; set; }

     public int DomainId { get; set; }

     public IEnumerable<Domain> Domains { get; set; }
}

My validator class:

public class ServicesViewModelValidator : AbstractValidator<ServicesViewModel>
{
     public ServicesViewModelValidator()
     {
          RuleFor(x => x.ComponentTypeId)
               .NotNull()
               .WithMessage("Required");

          RuleFor(x => x.DomainId)
               .NotNull()
               .WithMessage("Required");
     }
}

My http Post action method:

[HttpPost]
public ActionResult Services(ServicesViewModel viewModel)
{
     Check.Argument.IsNotNull(viewModel, "viewModel");

     if (!ModelState.IsValid)
     {
          viewModel.ComponentTypes = componentTypeRepository.FindAll();
          viewModel.Domains = domainRepository.FindAll();

          return View(viewModel);
     }

     return View(viewModel);
}

How do I get it to show my required message when nothing selected?

score 0 · Answer 1 · answered Feb 20 '13 at 14:32

I think the problem is that you are using an int for ComponentId instead of a nullable int. You are then using the NotNull() validator which will never trigger since an int can not be null.

Try switching it to this:

[Validator(typeof(ServicesViewModelValidator))]
public class ServicesViewModel
{
     public int? ComponentTypeId { get; set; }

     public IEnumerable<ComponentType> ComponentTypes { get; set; }

     public int DomainId { get; set; }

     public IEnumerable<Domain> Domains { get; set; }
}

If that dose not work then you could try to use a range validation:

public class ServicesViewModelValidator : AbstractValidator<ServicesViewModel>
{
     public ServicesViewModelValidator()
     {
          RuleFor(x => x.ComponentTypeId)
               .InclusiveBetween(1, int.MaxValue)
               .WithMessage("Required");

          RuleFor(x => x.DomainId)
               .NotNull()
               .WithMessage("Required");
     }
}

That would make it so that 0 is not a valid value.

How to get a required error message for radio buttons using FluentValidation

1 Answers1