GenericFactory, get current requested type, like it was possible in StructureMap

Hi, I know it’s not the best solution, but we have exactly that use case:

_.For(typeof(IFoo<>))
.Use(x =>
        {
            var ParamType = x.BuildStack.Current.RequestedType
                             .GetGenericArguments()[0];
            return BuildUsingFooFactory(ParamType);
        });
    }

Is there a way to get the information of the current requested type, like it was possible with StructureMap?

This question is quite similar, but unfortunately it has no answer: https://stackoverflow.com/questions/68832353/how-can-i-get-the-requested-type-in-a-usectx-factory-func-in-lamar-5 Br

[jeremydmiller]

@rizi Sorry for being slow here, yes, just throw new NotSupportedException() in those methods. If I get around to it, I can finally formalize this pattern a bit. It comes up a couple times a year.

[jeremydmiller]

You can use a custom Instance type for the parent, open type, then override the CloseType() method to return a subtype of LambaInstance that then calls through to your factory.

So something like:

public class MyBuilderInstance<T> : LambdaInstance<IFoo<T>>
{
    // and call through to the base constructor with s => BuildUsingFooFactory(typeof(T));
}

// and a custom instance like:

public class OpenFooInstance : Instance
{
  // override the CloseType() method to return the right MyBuilderInstance<T> where T would be the single template type
  // the service type should be typeof(IFoo<>)
}