NEW: Master Swift design patterns with my latest book! >>

< Previous: Setting up   Next: What can Instruments tell us? >

What are we working with?

This is a really simple app, albeit quite a broken one. Obviously the breakages are deliberate, but they are all things I have seen in real, shipping code. The app shows a table view containing garish images of popular internet acronyms.

When one of the rows is tapped, a detail view controller appears, showing the image at full size. Every time you tap on the big image, it adds one to a count of how many times that image was tapped, and that count is shown in the original view controller.

That’s it – that's all the app does. I haven't even used a storyboard, because I want all the problems to be visible (and fixable!) in Swift code.

And how bad are the problems? Well, if you run the app on a device, you'll probably find that it crashes after you’ve viewed several pictures – on my iPhone I get about two-thirds of the way through before it gives up.

You might also notice that scrolling isn’t smooth in the table view, particularly on older devices. If you scroll around a few times iOS might be able to smooth the scrolling a little, but you’ll certainly struggle to get it a flawless 60 frames per second – the gold standard for iOS drawing.

I hope you’ve never seen an app that manages to have all these problems at the same time, but I can guarantee you’ve seen apps that have one or two at a time. The goal of this project is to help you learn the skills needed to identify, fix, and test solutions to these common problems, so let’s dive in now…

Upgrade to the premium experience

Get all 40 projects in PDF and ePub, plus exclusive content that will take your Swift learning to the next level – buy the Hacking with Swift book today!

< Previous: Setting up   Next: What can Instruments tell us? >
Click here to visit the Hacking with Swift store >>