Book Image

Mastering iOS 12 Programming - Third Edition

By : Donny Wals
Book Image

Mastering iOS 12 Programming - Third Edition

By: Donny Wals

Overview of this book

The iOS development environment has significantly matured, and with Apple users spending more money in the App Store, there are plenty of development opportunities for professional iOS developers. However, the journey to mastering iOS development and the new features of iOS 12 is not straightforward. This book will help you make that transition smoothly and easily. With the help of Swift 4.2, you’ll not only learn how to program for iOS 12, but also how to write efficient, readable, and maintainable Swift code that maintains industry best practices. Mastering iOS 12 Programming will help you build real-world applications and reflect the real-world development flow. You will also find a mix of thorough background information and practical examples, teaching you how to start implementing your newly gained knowledge. By the end of this book, you will have got to grips with building iOS applications that harness advanced techniques and make best use of the latest and greatest features available in iOS 12.
Table of Contents (35 chapters)
Title Page
Copyright and Credits
Dedication
Packt Upsell
Contributors
Preface
Index

Implementing the prerequisites for background fetch


There are three steps involved in supporting background fetch in your app:

  1. Add the background fetch capability to your app.
  2. Ask iOS to wake your app up.
  3. Implement application(_:performFetchWithCompletionHandler:) in AppDelegate.

You can implement step 1 and 2 right now; step 3 will be implemented separately because this step will involve writing the code to fetch and update the movies using a helper struct.

Adding the background fetch capability

Every application has a list of capabilities they can opt in to. Some examples of these capabilities are using Maps, HomeKit, and Background Modes. You can find the Capabilities tab in your project settings. If you select your project in the file navigator, you can see the Capabilities tab right next to your app's General settings.

If you select this tab, you will see a list of all the capabilities your app can implement. If you expand a capability, you'll find some information about what the capability...