Book Image

React Native By Example

By : Richard Kho
Book Image

React Native By Example

By: Richard Kho

Overview of this book

React Native's ability to build performant mobile applications with JavaScript has resulted in its popularity amongst developers. Developers now have the luxury to create incredible mobile experiences that look and feel native to their platforms with the comfort of a well-known language and the popular React.js library. This book will show you how to build your own native mobile applications for the iOS and Android platforms while leveraging the finesse and simplicity of JavaScript and React. Throughout the book you will build three projects, each of increasing complexity. You will also link up with the third-party Facebook SDK, convert an app to support the Redux architecture, and learn the process involved in making your apps available for sale on the iOS App Store and Google Play. At the end of this book, you will have learned and implemented a wide breadth of core APIs and components found in the React Native framework that are necessary in creating great mobile experiences.
Table of Contents (17 chapters)
Title Page
Credits
Foreword
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

BackAndroid


The last thing we need to handle is the back button. A universal back button, either a hardware or software implementation, is found on each Android device. We will need to use the BackAndroid API to detect back button presses and set our own custom functionality. If we don't do this, the back button will automatically close the app each time it is pressed.

To use it, we can add an event listener during the componentWillMount life cycle event that will pop the navigator when a back button press is detected. We can also remove the listener when the component is unmounted.

During componentWillMount, add an event listener to the BackAndroid API for a hardwareButtonPress event, firing _backButtonPress when triggered:

// Tasks/app/components/EditTask/index.android.js 

... 
import { 
  BackAndroid, 
  ... 
} from 'react-native'; 
... 
export default class EditTask extends Component { 
  ... 
  componentWillMount () { 
    BackAndroid.addEventListener('hardwareButtonPress', () => ...