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

47.12 Widget Placeholder

As previously mentioned, the widget extension must provide a placeholder. This is the view which is displayed to the user while the widget is initializing and takes the form of the widget entry view without any data or information. Consider the following example widget:

Figure 47-2

The above example, of course, shows the widget running after it has received timeline data to be displayed. During initialization, however, the placeholder view resembling Figure 47-3 would be expected to be displayed:

Figure 47-3

Fortunately, SwiftUI includes the redacted(reason:) modifier which may be applied to an instance of the widget entry view to act as a placeholder. The following is an example of a placeholder view declaration for a widget extension using the redacted() modifier (note that the reason is set to placeholder):

struct PlaceholderView : View {

    var body: some View {

       ...