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)

Sharing state objects with multiple Views using @EnvironmentObject

In many cases, there are dependent collaborators that must be shared between several Views, even without having a tight relationship between them. Think of a ThemeManager, or a NetworkManager, or a UserProfileManager.

Passing them through the chain of Views can be annoying, without even thinking of the coupling we could create. If a view doesn't need the NetworkManager instance, for example, it should still have it as a property in case one of its child Views needs it.

SwiftUI solves this with the concept of Environment, a place to add common objects – usually ObservableObject objects – that will be shared between a chain of Views. An Environment is started in the root ancestor of the view graph and can be changed further down in the chain by us adding new objects.

To present this feature, we are going to implement a basic song player with three Views:

  • A View for the list of songs...