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

Understanding the use of multiple instances of NSManagedObjectContext


It has been mentioned several times in this chapter that you can use multiple managed object contexts. In many cases, you will only need a single managed object context. Using a single managed object context means that all of the code related to the managed object context is executed on the main thread. If you're performing small operations, that's fine. However, imagine importing large amounts of data. An operation such as that could take a while. Executing code that runs for a while on the main thread will cause the user interface to become unresponsive. This is not good, because the user will think your app has crashed. So how do you work around this? The answer is using multiple managed object contexts.

 

In the past, using several managed object contexts was not easy to manage; you had to create instances of NSManagedObjectContext using the correct queues yourself. Luckily, NSPersistentContainer helps to make complex...