I am using Castle Windsor.
I have two component types where the implementation can be selected at runtime on a GUI. To handle this, I am resolving them by name. To handle resolving them by name, I am using the Typed Factory Facility.
One of the component types depends on the other. To handle the dependency, I am passing the argument as a factory method/constructor parameter argument.
Here is a redacted and abridged version of this factory interface:
public interface IModelFactory
{
IMyDomainCommandFactory GetFooCommandFactory();
IMyDomainCommandFactory GetBarCommandFactory();
IMyDomainStrategy GetCreateSpecificSizeStrategy(int size, IMyDomainCommandFactory commandFactory);
IMyDomainStrategy GetCreateUntilFailureStrategy(IMyDomainCommandFactory commandFactory);
}
Note that I am using my own implementations for IMyDomainCommandFactory
, rather than using the Typed Factory facility. Those factories have intentionally complex behavior, and the facility doesn't suit their needs.
The problem I am noticing is that if I register my strategy components with a singleton lifestyle, I always get back the same instance, even if I pass different arguments to the getter.
In my opinion, this goes against the Principal of Least Astonishment, but maybe other people have a different opinion :) Should this be considered a bug?
If not, is there a clean way to get the container or factory to create only one instance per argument combination?
Depending how you look at it, but certainly instance per combination of parameters can't be called a singleton so I say it would go against PoLA if Windsor did implement the behavior you'd expect.
If you want it, you need a custom, non-singleton lifestyle.