A while ago I faced a problem with controllers for nested resources I wanted to reuse in different contexts (polymorphic resources). For example, I had a simple Todo model that is used to store tasks that have to be done. Having multiple users which are organized in teams, the goal was to have user-specific (personal) todos and team-specific todos. Obviously, both kind of todos could be handled exactly the same way (same controller, same views) – except that the context differs.

So here’s a way to use a single controller for a polymorphic resource.