Dependency-Injected Validation in Web API

Question

In MVC, I can create a Model Validator which can take Dependencies. I normally use FluentValidation for this. This allows me to, for example, check on account registration tha

Answer 1

I spent a lot of time trying to find a good way around the fact that WebApi ModelValidatorProvider stores the validators as singletons. I didn't want to have to tag things with validation filters, so I ended up injecting IKernel in the validator and using that to get the context.

public class RequestValidator : AbstractValidator{
    public readonly IDbContext context;

    public RequestValidator(IKernel kernel) {
        this.context = kernel.Get();

        RuleFor(r => r.Data).SetValidator(new DataMustHaveValidPartner(kernel)).When(r => r.RequestableKey == "join");
    }
}

This seems to work even though the validator is stored as a singleton. If you also want to be able to call it with the context, you could just create a second constructor that takes IDbContext and make the IKernel constructor pass IDbContext using kernel.Get()