I'm looking for something a bit different than regular app authorization; I need a tool for managing user authorization against resources related to generic projects or items, similar to what Backpack does with page participation. For example, there is a pool of users, and when an admin creates a new project (or, more generically, "item parent"), that admin can assign access to this project and all its related resources to anyone in the group.
Role-based authorization is the right answer to some degree, but in this scenario, the role becomes a resource itself, with related resources (documents, images, info).
I don't think it will be particularly difficult to build something generic to solve this issue, I just want to be sure I'm not reinventing the wheel.
Thanks for your help.