/// <summary>
/// Checks if requests item is not null and if it has value validates by nested validator.
/// </summary>
/// <param name="instance"></param>
/// <returns></returns>
public override ValidationResult Validate(T instance)
{
var result = base.Validate(instance);
var innerType = typeof(T).GetGenericArguments().First();
var validator = ValidationEngine.GetValidator(innerType);
if (validator == null)
{
return(result);
}
var itemValidation = validator.Validate(instance.Item);
if (itemValidation.IsValid)
{
return(result);
}
return(new ValidationResult((result.Errors ?? new List <ValidationFailure>()).Concat(itemValidation.Errors)));
}