Bucket List: Wrap up

Paul Hudson    @twostraws    December 4th 2019

This was our biggest project yet, but we’ve covered a huge amount of ground: adding Comparable to custom types, finding the documents directory, integrating MapKit, using biometric authentication, secure Data writing, and much more. And of course you have another real app, and hopefully you’re able to complete the challenges below to take it further.

Between this and Instafilter you’ve now seen how to embed any part of UIKit into your app – any UIView or UIViewController can now be placed inside SwiftUI. This massively widens the types of apps you can build, as long as you’re able to spend the time learning some UIKit. Over time SwiftUI will grow and expand what it’s capable of, but right now it’s important to know its limits and play to its strengths!

Review what you learned

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.

Click here to review what you learned in this project.

Challenge

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.

1. Our + button is rather hard to tap. Try moving all its modifiers to the image inside the button – what difference does it make, and can you think why?
2. Having a complex if condition in the middle of ContentView isn’t easy to read – can you rewrite it so that the MapView, Circle, and Button are part of their own view? This might take more work than you think!
3. Our app silently fails when errors occur during biometric authentication. Add code to show those errors in an alert, but be careful: you can only add one alert() modifier to each view.