Challenge

It’s time for you to build an app from scratch, and it’s a particularly expansive challenge today: your job is to use URLSession to download some JSON from the internet, use Codable to convert it to Swift types, then use NavigationView, List, and more to display it to the user.

Your first step should be to examine the JSON. The URL you want to use is this: https://www.hackingwithswift.com/samples/friendface.json – that’s a massive collection of randomly generated data for example users.

As you can see, there is an array of people, and each person has an ID, name, age, email address, and more. They also have an array of tag strings, and an array of friends, where each friend has a name and ID.

How far you implement this is down to you, but at the very least you should:

• Fetch the data and parse it into User and Friend structs.
• Display a list of users with a little information about them.
• Create a detail view shown when a user is tapped, presenting more information about them.

Where things get more interesting is with their friends: if you really want to push your skills, think about how to show each user’s friends on the detail screen.

For a medium-sized challenge, show a little information about their friends right on the detail screen. For a bigger challenge, make each of those friends tappable to show their own detail view.

Even though there’s a lot of data, we’re only working with 100 friends at a time – using something like first(where:) to find friends in the array is perfectly fine.

If you’re not sure where to begin, start by designing your types: build a User struct with properties for name, age, company, and so on, then a Friend struct with id and name. After that, move onto some URLSession code to fetch the data and decode it into your types.

While you’re building this, I want you to keep one thing in mind: this kind of app is the bread and butter” of iOS app development – if you can nail this with confidence, you’re well on your way to a full-time job as an app developer.