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
Packt Upsell

Updating Core Data objects with fetched data

So far, the only thing you have stored in Core Data is movie names. You will expand this functionality by performing a lookup for a certain movie name through the movie database API. The fetched information will be used to display and store a popularity rating for the movies in the Core Data database.

A task such as this seems straightforward at first; you could come up with a flow such as the one shown in the following steps:

  1. A user indicates their favorite movie.
  2. The movie's popularity rating is fetched.
  3. The movie and its rating are stored in the database.
  4. The interface updates with the new movie.

At first glance, this is a fine strategy; insert the data when you have it. However, it's important to consider that API calls are typically done asynchronously so the user interface stays responsive. More importantly, API calls can be really slow if your user doesn't have a good internet connection. This means that you would be updating the interface with...