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)

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 ThemeManager, or NetworkManager, or UserProfileManager.

Passing them through the chain of Views can be really annoying, without thinking of the coupling we could create. If a view doesn't need NetworkManager, 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, which will be shared between a chain of Views. An Environment is started in the root ancestor of the view graph, and it can be changed further down in the chain, adding new objects.

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

  • A list of songs view
  • A mini player view, always on top of...