Dynamically Add DataAnnotations Attributes to a view model depending on value of fields in model

Question

I have a class Lets say

public class Customer { public int id; public string FirstName {get;set;} public string LastName {get;set;} public string JobName {get;set;} public double Salary {get;set;}

}

A grid shows all these customers on a page. However, depending on Customer selected say id=1 , I want FirstName to have a StringLengthAttribute in Validation Vs some other RegexAttribute/other CustomValidation Attribute or even same one with different value for customer id= 2

Can we inject the datannotations attribute dynamically to the model.

Below is what I was trying to do but does not seem to work.

public class CustomValidatorProvider : AssociatedValidatorProvider {

    protected override IEnumerable<ModelValidator> GetValidators(ModelMetadata metadata, ControllerContext context, IEnumerable<Attribute> attributes)
    {
        if (context.HttpContext.Session["customerid"].ToString().Equals(  "1"))
        {
            if (metadata != null && metadata.PropertyName != null && metadata.PropertyName.Equals("FirstName"))
            {
                StringLengthAttributeAdapter a = new StringLengthAttributeAdapter(metadata, context, new StringLengthAttribute(5));   
                yield return a;
            }
        }

        if (context.HttpContext.Session["customerid"].ToString().Equals(  "2"))
        {
            if (metadata != null && metadata.PropertyName != null && metadata.PropertyName.Equals("FirstName"))
            {
                StringLengthAttributeAdapter a = new StringLengthAttributeAdapter(metadata, context, new StringLengthAttribute(15));   
                yield return a;
            }
        }

    }
}

and then register in global.asax as ModelValidatorProviders.Providers.Add(new CustomValidatorProvider());

Answer 1

Did it work?, Me too looking for solution.