While working on an angular.js application recently, I found myself needing some form of authorization logic (not to be confused with authentication / login). I needed to restrict content in my app based on a user’s role as well as some other factors. At first, I created a single AuthService service that dealt with login, authorization, and session management. But this felt messy and violated the Single Responsibility Principle, so I decided to make something cleaner. My goal was for the API to look something like this: