Book Image

SwiftUI Essentials – iOS 14 Edition

By : Neil Smyth
Book Image

SwiftUI Essentials – iOS 14 Edition

By: Neil Smyth

Overview of this book

Do you want to create iOS apps with SwiftUI, Xcode 12, and Swift 5.3, and want to publish it on the app store? This book helps you achieve these skills with a step-by-step approach. This course first walks you through the steps necessary to set up an iOS development environment together and introduces Swift Playgrounds to learn and experiment with Swift—specifically, the Swift 5.3 programming language. After establishing key concepts of SwiftUI and project architecture, this course provides a guided tour of Xcode in SwiftUI development mode. The book also covers the creation of custom SwiftUI views and explains how these views are combined to create user interface layouts, including the use of stacks, frames, and forms. One of the more important skills you’ll learn is how to integrate SwiftUI views into existing UIKit-based projects and explain the integration of UIKit code into SwiftUI. Finally, the book explains how to package up a completed app and upload it to the app store for publication. Along the way, the topics covered in the book are put into practice through detailed tutorials, the source code for which is also available for download. By the end of this course, you will be able to build your own apps for iOS 14 using SwiftUI and publish it on the app store. The code files for the book can be found here: https://www.ebookfrenzy.com/retail/swiftui-ios14/
Table of Contents (56 chapters)
56
Index

26.7 Summary

The @SceneStorage and @AppStorage property wrappers provide two ways to persistently store small amounts of data within a SwiftUI app. Scene storage is intended primarily for saving and restoring the state of a scene when an app is terminated while in the background. Each scene within an app has its own local scene storage which is not directly accessible to other areas of the app. App storage uses the UserDefaults system and is used for storing data that is to be accessible from anywhere within an app. Through the use of App Groups, app storage may also be shared between different targets within the same app project, or even entirely different apps. Changes to app storage are immediate regardless of whether the app is currently in the foreground or background.

Both the @AppStorage and @SceneStorage property wrappers support storing Bool, Int, Double, String, URL and Data types. Other types need to be encoded and encapsulated in Data objects before being placed into...