This app is the most complex one we’ve built so far. Yes, there are multiple views, but we also strayed away from lists and forms and into our own scrolling layouts, using
GeometryReader to get precise sizes to make the most of our space.
But this was also the most complex Swift code we’ve written so far – generics are an incredibly powerful feature, and once you add in constraints you open up a huge range of functionality that lets you save time while also gaining flexibility. You’re also now starting to see how useful
Codable is: its ability to decode a hierarchy of data in one pass is invaluable, which is why it’s central to so many Swift apps.
Anyone can sit through a tutorial, but it takes actual work to remember what was taught. It’s my job to make sure you take as much from these tutorials as possible, so I’ve prepared a short review to help you check your learning.
One of the best ways to learn is to write your own code as often as possible, so here are three ways you should try extending this app to make sure you fully understand what’s going on.
MissionView, below the mission badge.
AstronautViewto show all the missions this astronaut flew on.
ContentViewthat toggles between showing launch dates and showing crew names.
The first challenge should be trivial, the second trickier, and the last one… well, let’s just say it will push you. Don’t be surprised if it takes you much longer than you think!
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