Multiple validation schemes with attributes

Question

I am using data annotations in C# to validate a POCO class. I would like to be able to specify different validation schemes in different situations. Eg minimum validation for trusted data sources, but a higher level of validation for data collected via a website form open to the public.

I've Googled and i'm not sure if: A) I'm not using the right terms, or B) this is the wrong approach entirely which is why i'm not finding anything. It seems like this might be a common need.

To illustrate what i'd like to do:

public class TestClass { 

    [Required]
    [EmailAddress]
    [WhitelistCharactersOnly(ValidationScheme = ValidationSchemes.Untrusted)]
    public string EmailAddress { get; set; }

}

I understand that I could do something with custom attributes but i'd like to avoid reinventing the wheel if possible.

So as not to solicit too much debate, my question is this: Is there a way to achieve what I want to do that is part of the C# framework at present?

Answer 1

If you're using the MVC framework for validation you can take advantage of the MetadataTypeAttribute .

[MetadataType(typeof(ICustomerValidation1))]
public class CustomerValidation1 : CustomerBase { }

public class CustomerBase
{
  public string Title { get; set; }
}


public interface ICustomerValidation1
{
  // Apply RequiredAttribute
  [Required(ErrorMessage = "Title is required.")]
  string Title { get; }
}