Model-bind interface property with Web API

Question

I have a command looking like:

public interface ICommand {
    // Just a marker interface
}

public interface IUserAware {
    Guid UserId { get; set; }
}

p         


        

Answer 1

Based on @Todd last comment, the answer to the question is:

Create a HttpParameterBinding class:

public class UserAwareHttpParameterBinding : HttpParameterBinding
{
    private readonly HttpParameterBinding _paramaterBinding;
    private readonly HttpParameterDescriptor _httpParameterDescriptor;

    public UserAwareHttpParameterBinding(HttpParameterDescriptor descriptor) : base(descriptor)
    {
        _httpParameterDescriptor = descriptor;
        _paramaterBinding = new FromBodyAttribute().GetBinding(descriptor);
    }

    public override async Task ExecuteBindingAsync(ModelMetadataProvider metadataProvider, HttpActionContext actionContext, CancellationToken cancellationToken)
    {
        await _paramaterBinding.ExecuteBindingAsync(metadataProvider, actionContext, cancellationToken);

        var baseModel = actionContext.ActionArguments[_httpParameterDescriptor.ParameterName] as IUserAware;
        if (baseModel != null)
        {
            baseModel.UserId = new Guid("6ed85eb7-e55b-4049-a5de-d977003e020f"); // Or get it form the actionContext.RequestContext!
        }
    }
}

And wire it up in the HttpConfiguration:

configuration.ParameterBindingRules.Insert(0, descriptor => typeof(IUserAware).IsAssignableFrom(descriptor.ParameterType) ? new UserAwareHttpParameterBinding(descriptor) : null);

If anyone know how this is done in .NET Core MVC - please edit this post or comment.