fluent validation with when on client side

Question

In a ASP.NET MVC4 application we are using FluentValidation for validating our models. In certain cases we only want to validate a property when another property has a value. We use the When keyword to accomplish this. A simple validation class looks like this:

public class PersonValidator : AbstractValidator<Person>
{
    public PersonValidator()
    {
        RuleFor(item => item.FirstName).NotEmpty();
        RuleFor(item => item.LastName).NotEmpty().When(item => !string.IsNullOrEmpty(item.FirstName))
    }
}

We would like to have client side validation for this. I tried to create a custom FluentValidationPropertyValidator. But I can't find a way to pickup the When part of the validation rule. Can someone point me in right direction?

Answer 1

FluentValidation does now support client-side validation. The following validators are supported on the client:

• NotNull/NotEmpty
• Matches (regex)
• InclusiveBetween (range)
• CreditCard
• Email
• EqualTo (cross-property equality comparison)
• MaxLength
• MinLength
• Length

https://fluentvalidation.net/aspnet