Question

The Gu provides an example of how you might create a custom validator that overrides RegularExpressionAttribute .

The advantage of this is that you don’t have to create a custom Model Validator but I can’t get it to work.

Given the following code:

public class NameAttribute : RegularExpressionAttribute {
    public NameAttribute()
        : base(@"^[\w\s\-\']+$") {
    }
}

This works:

[RegularExpression(@"^[\w\s\-\']+$")]

But this doesn’t:

[Name]

Have I misunderstood an aspect of Scott’s example or is the example flawed in that MVC doesn’t support derived types out of the box, so actually I will have to create a a corresponding ModelValidator?

Answer 1

Cracked it! Add the following to Global.asax.cs Application_Start()

DataAnnotationsModelValidatorProvider.RegisterAdapter(typeof(NameAttribute), typeof(RegularExpressionAttributeAdapter));