How to use FluentValidation with Web Api 2.0?

Question

I am trying to use Fluent Validation in a web api 2 project but I can't get the Model State to work. I downloaded this nuget package and added this line to my Application_Start

      FluentValidationModelValidatorProvider.Configure(GlobalConfiguration.Configuration);

Then in my model I added

 [Validator(typeof(LotValidator))]

yet my ModelState.IsValid is always valid. I don't know what I am missing or if it the fact that I have my model in a different class project(though I do reference the FluentValidation package) then my webapi project.

Answer 1

You might not have added ValidateModelStateFilter to the filters.

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        //Fluent Validation
        config.Filters.Add(new ValidateModelStateFilter());
        FluentValidationModelValidatorProvider.Configure(config);

        //snip..    
    }
}

I have a long post on how to do everything here - http://nodogmablog.bryanhogan.net/2016/12/fluent-validation-with-web-api-2/