Book Image

SwiftUI Cookbook - Second Edition

By : Giordano Scalzo, Edgar Nzokwe
Book Image

SwiftUI Cookbook - Second Edition

By: Giordano Scalzo, Edgar Nzokwe

Overview of this book

SwiftUI provides an innovative and simple way to build beautiful user interfaces (UIs) for all Apple platforms, from iOS and macOS through to watchOS and tvOS, using the Swift programming language. In this recipe-based cookbook, you’ll cover the foundations of SwiftUI as well as the new SwiftUI 3 features introduced in iOS 15 and explore a range of essential techniques and concepts that will help you through the development process. The cookbook begins by explaining how to use basic SwiftUI components. Once you’ve learned the core concepts of UI development, such as Views, Controls, Lists, and ScrollViews, using practical implementations in Swift, you'll advance to adding useful features to SwiftUI using drawings, built-in shapes, animations, and transitions. You’ll understand how to integrate SwiftUI with exciting new components in the Apple development ecosystem, such as Combine for managing events and Core Data for managing app data. Finally, you’ll write iOS, macOS, and watchOS apps by sharing the same SwiftUI codebase. By the end of this SwiftUI book, you'll have discovered a range of simple, direct solutions to common problems encountered when building SwiftUI apps.
Table of Contents (17 chapters)

Pulling and refreshing data asynchronously in SwiftUI

Pull-to-refresh is an established touchscreen gesture to refresh a List view. First implemented in Tweetie, one of the first iOS apps for Twitter, it is now part of the iOS SDK. Originally supported only in UIkit, iOS 15 offers support for it in SwiftUI, and as expected, it works well with the async await model.

In this recipe, we are going to implement an app that fetches a few random cryptocurrencies and presents them in a List view.

Pulling the List, the app fetches another sample of the currencies updating the List. The network service we will use for this is called Random Data Generator (https://random-data-api.com). It offers several types of random data, as you can see from its help page:

The recipe fetches cryptocurrencies, but you can experiment with the same code using another endpoint.

Getting ready

Implement an iOS 15 SwiftUI app called RefreshableCrypto.

How to do it…

As typical for an...