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

46.2 App Groups and UserDefaults

Much about the way in which the app has been constructed will be familiar from techniques outlined in previous chapters of the book. The project also makes use of app storage in the form of UserDefaults and the @AppStorage property wrapper, concepts which were introduced in the chapter entitled “SwiftUI Data Persistence using AppStorage and SceneStorage”. The ShortcutDemo app uses app storage to store an array of objects containing the symbol, quantity and time stamp data for all stock purchase transactions. Since this is a test app that needs to store minimal amounts of data, this storage is more than adequate. In a real-world environment, however, a storage system capable of handling larger volumes of data such as SQLite, CoreData or iCloud storage would need to be used.

In order to share the UserDefaults data between the app and the SiriKit intents extension, the project also makes use of App Groups. App Groups allow apps to share...