We come back to our unfinished Swift Talk iOS app and implement a lightweight network cache for offline support. We keep our networking code from episode #1 untouched to maintain a clear separation of concerns.
We build a flexible sort descriptor abstraction, similar to NSSortDescriptor, on top of Swift's native sort methods. Because we make use of generics and first-class functions, the result is dynamic and type safe.
We refactor our code by moving the app's flow from the storyboard into a separate class. Our goal is to manage the view controller flow from a central place so that view controllers don't have implicit knowledge of their context.