code snippets for "Customizing ASP.NET MVC’s Required Property Validation Messages" post

s1.cs

public class ConventionsBasedRequiredAttributeAdapter : RequiredAttributeAdapter
{
    public ConventionsBasedRequiredAttributeAdapter(ModelMetadata metadata, ControllerContext context, RequiredAttribute attribute)
        : base(metadata, context, attribute) {}
 
    public override IEnumerable<ModelClientValidationRule> GetClientValidationRules()
    {
        string errorMessage;
 
        var className = Metadata.ContainerType.Name;
        var propertyName = Metadata.PropertyName;
 
        var specificKey = string.Format("{0}_{1}_required", className, propertyName);
        // TODO: make the ResourceManager configurable
        errorMessage = Resources.ResourceManager.GetObject(specificKey) as string;
 
        if (string.IsNullOrEmpty(errorMessage))
        {
            var genericMessageWithPlaceHolder = (string)Resources.ResourceManager.GetObject("Generic_required_field_message");
 
            if (!string.IsNullOrEmpty(genericMessageWithPlaceHolder))
            {
                errorMessage = string.Format(genericMessageWithPlaceHolder, Metadata.DisplayName);
            }
        }
 
        if (string.IsNullOrEmpty(errorMessage))
        {
            errorMessage = ErrorMessage; // fallback to what ASP.NET MVC would normally display
        }
 
        return new[] { new ModelClientValidationRequiredRule(errorMessage) };
    }
}

s2.cs

DataAnnotationsModelValidatorProvider.RegisterAdapterFactory(typeof(RequiredAttribute),
    (metadata, controllerContext, attribute) => new ConventionsBasedRequiredAttributeAdapter(metadata,
        controllerContext, (RequiredAttribute)attribute));