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.
We extend the networking code from the first episode to support POST requests. Besides using Swift's enums with associated values and generics, we get to implement a map function on a custom data type.
We build a tree structure beginning with a flat array of Ledger account names. We first implement the tree using a class, and then we refactor it to a struct and discuss the differences and tradeoffs involved.
In this episode, we implement search functionality for our Ledger GUI app. In the process, we leverage several aspects we've talked about before, such as connecting view controllers, managing application state, and parsing user input.
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 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 show how to make an extension on array available to other collections: first, we implement it for array slices, then we implement it as a protocol extension for all collections.