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

Understanding HealthKit

HealthKit is a framework that allows developers to interact with a user's health data. This data includes information like a user's weight, BMI, blood type, biological sex, skin type, date of birth, whether they use a wheelchair, and much more. In addition to these metrics, HealthKit also provides access to activity data, such as workouts or the amount of steps the user has walked on a given day.


HealthKit is available on the iPhone and Apple Watch only. The iPad does not have support for HealthKit, so you must take special precautions to determine whether HealthKit is available, by calling isHealthDataAvailable() on the HKHealthStore class.

Because health data is considered private and thus very sensitive, apps that want access to health data have to specify their reasons for wanting to read and/or write data to HealthKit in the Info.plist, under the following keys:

  • Privacy: Health Share Usage Description (NSHealthShareUsageDescription) for reading data from the...