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1. Start Here
The goal of this book is to teach the skills necessary to build iOS 15 applications using SwiftUI, Xcode 13 and the Swift 5.5 programming language.
Beginning with the basics, this book provides an outline of the steps necessary to set up an iOS development environment together with an introduction to the use of Swift Playgrounds to learn and experiment with Swift.
The book also includes in-depth chapters introducing the Swift 5.5 programming language including data types, control flow, functions, object-oriented programming, property wrappers, structured concurrency, and error handling.
An introduction to the key concepts of SwiftUI and project architecture is followed by 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.
Other topics covered include data handling using state properties in addition to observable, state and environment objects, as are key user interface design concepts such as modifiers, lists, tabbed views, context menus, user interface navigation, and outline groups.
The book also includes chapters covering graphics drawing, user interface animation, view transitions and gesture handling, WidgetKit, document-based apps, Core Data, CloudKit, and SiriKit integration.
Chapters are also provided explaining how to integrate SwiftUI views into existing UIKit-based projects and explains 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.
The aim of this book, therefore, is to teach you the skills necessary to build your own apps for iOS 15 using SwiftUI. Assuming you are ready to download the iOS 15 SDK and Xcode 13 and have an Apple Mac system you are ready to get started.
1.1 For Swift Programmers
This book has been designed to address the needs of both existing Swift programmers and those who are new to both Swift and iOS app development. If you are familiar with the Swift 5.5 programming language, you can probably skip the Swift specific chapters. If you are not yet familiar with the SwiftUI specific language features of Swift, however, we recommend that you at least read the sections covering implicit returns from single expressions, opaque return types and property wrappers. These features are central to the implementation and understanding of SwiftUI.
1.2 For Non-Swift Programmers
If you are new to programming in Swift then the entire book is appropriate for you. Just start at the beginning and keep going.
1.3 Source Code Download
The source code and Xcode project files for the examples contained in this book are available for download at:
https://www.ebookfrenzy.com/retail/swiftui-ios15/
1.4 Feedback
We want you to be satisfied with your purchase of this book. If you find any errors in the book, or have any comments, questions or concerns please contact us at
[email protected].
1.5 Errata
While we make every effort to ensure the accuracy of the content of this book, it is inevitable that a book covering a subject area of this size and complexity may include some errors and oversights. Any known issues with the book will be outlined, together with solutions at the following URL:
https://www.ebookfrenzy.com/errata/swiftui-ios15.html
In the event that you find an error not listed in the errata, please let us know by emailing our technical support team at
[email protected].
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2. Joining the Apple Developer Program
The first step in the process of learning to develop iOS 15 based applications involves gaining an understanding of the advantages of enrolling in the Apple Developer Program and deciding the point at which it makes sense to pay to join. With these goals in mind, this chapter will outline the costs and benefits of joining the developer program and, finally, walk through the steps involved in enrolling.
2.1 Downloading Xcode 13 and the iOS 15 SDK
The latest versions of both the iOS SDK and Xcode can be downloaded free of charge from the macOS App Store. Since the tools are free, this raises the question of whether to enroll in the Apple Developer Program, or to wait until it becomes necessary later in your app development learning curve.
2.2 Apple Developer Program
Membership in the Apple Developer Program currently costs $99 per year to enroll as an individual developer. Organization level membership is also available.
Prior to the introduction of iOS 9 and Xcode 7, one of the key advantages of the developer program was that it permitted the creation of certificates and provisioning profiles to test your applications on physical iOS devices. Fortunately, this is no longer the case and all that is now required to test apps on physical iOS devices is an Apple ID.
Clearly much can be achieved without the need to pay to join the Apple Developer program. There are, however, areas of app development which cannot be fully tested withou...
