Unity Register type mapping if missing?

Question

This is similar to This question but the answer doesn't solve my problem.

I want to register a default implementation for an interface in code but be able to override that in a config that is read BEFORE the code is run.

I want to do something like

if (!container.IsImplementationRegistered(typeof(TInterface))
{
  container.RegisterType<TInterface, TImplementation>();
}

I can't use TryResolve as I will be registering several types in a row that might have dependencies of their own that aren't yet registered, leading to an erroneous override.

Will Unity 2.0 enable this or is there a way to do it in 1.2?

Answer 1

Maybe you can try with a child container.

1. Create a container in the code
2. Create a child container using CreateChildContainer()
3. Configure the child container reading from the config file
4. Use the child container in the application.

If the child container cannot resolve a type, Unity goes to the parent container to resolve.