Silverlight 4: Localization of built-in data annotation validation exceptions

Question

I would like use data annotations to handle validation in my Silverlight app. The built-in validation attributes (primarily StringLength and Required) are great, and make life very easy. However, they seem to have one critical flaw. If my locale is set to fr-CA, for example, the validation exceptions are still in English - 'The Name field is required', 'The field Name must be a string with a maximum length of 20', etc.

This is a major problem. It means that if I want localized error messages for the built-in validation attributes, I have to manually add ErrorMessage/ErrorMessageResourceType to every validation attribute on every validatable property in my business layer, and manually add translated strings for every error message.

So... am I missing something here? Is there a way to automatically have the built-in validation attributes localized? Or some other easier way of doing this? Or am I just completely out of luck, and stuck with the manual route?

Any comments or thoughts would be appreciated.

Answer 1

Ok, I got around this by simply subclassing the built-in validation attributes. Problem solved!

internal class LocalizedStringLengthAttribute : StringLengthAttribute
{
    public LocalizedStringLengthAttribute(int maximumLength)
        : base(maximumLength)
    {

    }

    public override string FormatErrorMessage(string name)
    {
        return String.Format(CultureInfo.CurrentUICulture, LanguageResources.Resource.Error_StringLength, name, MaximumLength);
    }
}