React Native By Example

Adding PostView navigator and BackAndroid support

Now, let's modify the PostView component with the following changes:

• Import the Platform and BackAndroid APIs
• Add and remove listeners for BackAndroid during componentWillMount and componentWillUnmount

• Write a callback in the component to handle back button presses on Android, calling pop on the navigator as a result
• Create conditional logic similar to FeedListRow to push the WebViewComponent

I created an event listener for BackAndroid in the componentWillMount lifecycle:

 // Friends/app/components/PostView/index.js ... import { BackAndroid, Platform, ... } from 'react-native'; ... export default class PostView extends Component { ... async componentWillMount () { BackAndroid.addEventListener('hardwareButtonPress', ...