Book Image

SwiftUI Cookbook

By : Giordano Scalzo, Edgar Nzokwe
Book Image

SwiftUI Cookbook

By: Giordano Scalzo, Edgar Nzokwe

Overview of this book

SwiftUI is an innovative and simple way to build beautiful user interfaces (UIs) for all Apple platforms, right from iOS and macOS through to watchOS and tvOS, using the Swift programming language. In this recipe-based book, you’ll work with SwiftUI and explore a range of essential techniques and concepts that will help you through the development process. The recipes cover the foundations of SwiftUI as well as the new SwiftUI 2.0 features introduced in iOS 14. Other recipes will help you to make some of the new SwiftUI 2.0 components backward-compatible with iOS 13, such as the Map View or the Sign in with Apple View. The cookbook begins by explaining how to use basic SwiftUI components. Then, you’ll learn the core concepts of UI development such as Views, Controls, Lists, and ScrollViews using practical implementation in Swift. By learning drawings, built-in shapes, and adding animations and transitions, you’ll discover how to add useful features to the SwiftUI. When you’re ready, 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 while 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 found in building SwiftUI apps.
Table of Contents (15 chapters)

Implementing asynchronous images in SwiftUI

Most of the app you are going to implement depends on a remote service that provides data.

Imagine an e-commerce app or a hotel booking app.

All the content is on the server, and the app must download it and present it smoothly, taking care of the possible delay, lag, error, and so on. An essential part of this content is images. We could download and synchronously present images, but that would mean blocking the UI waiting for the download, making the app clunky and unpleasant to use.

That said, implementing images that asynchronously download and present themselves is a valuable tool to have in our toolbox.

In this recipe, we are going to implement an AsyncImage component that you can reuse in your apps whenever you need this feature.

Getting ready

No external resources are needed in this recipe, so just create a SwiftUI project in Xcode called AsyncImageApp.

How to do it

Two ingredients make the recipe: an ImageFetcher...