ASP.NET MVC 2 - Property validation

Question

I'm new to MVC and have a question regarding validation. Is there a way to dynamically set the Error Message?

For example, how could I achieve the following (ignore the hardcoded 50, this could come from the Web.config or specific to the current logged).

[MetadataType(typeof(DocumentValidation))]
public partial class Document
{
    public class DocumentValidation
    {
        private const int MaxLength = 50;

        [Required(ErrorMessage = "Document Title is required")]
        [StringLength(MaxLength, ErrorMessage = "Must be under " + MaxLength.ToString() + " characters")]
        public string Title { get; set; }
    }

}

Thanks,

Answer 1

Depending how dynamically you're trying to change ErrorMessage. This might be one solution to your problem: haacked.com - Localizing ASP.NET MVC Validation

It's a good guide to get localized error message from the resources.´

Answer 2

Check out IDataErrorInfo and this question I asked about IDataErrorInfo vs. DataAnnotations.

Answer 3

This should be possible with dynamic attributes but involves some trickery:

Dynamic Attributes in C#