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.
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 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.