karbyninc

public class CustomerValidator: AbstractValidator 
{
  public CustomerValidator() 
   {
    RuleFor(customer => customer.Surname).NotEmpty();
    RuleFor(customer => customer.Forename).NotEmpty().WithMessage("Please specify a first name");
    RuleFor(customer => customer.Discount).NotEqual(0).When(customer => customer.HasDiscount);
    RuleFor(customer => customer.Address).Length(20, 250);
    RuleFor(customer => customer.Postcode).Must(BeAValidPostcode).WithMessage("Please specify a valid postcode");
  }

karbyninc

public class EntityController : ApiController
{
   public SomeDto Get()
   {
     //return some DTO
   }
}