When building a cross-platform app, the need to write different code for different platforms may arise. This can always be achieved by organizing the various components in different folders:
/common/components/ /android/components/ /ios/components/
Another option may be naming the components differently depending on the platform they are going to be used in:
BigButtonIOS.js BigButtonAndroid.js
But React Native provides two alternatives to easily organize your code separating it by platform:
Platform specific extensions
React Native will detect when a file has a .ios.
or .android.
extension and load the right file for each platform when requiring them from other components.
For example, you can have these files in your project:
BigButton.ios.js BigButton.android.js
With this setup, you can just require the files from a different component without paying attention to the platform in which the app will run.
import BigButton from './components/BigButton';
React Native will import the correct component for the running platform.
Platform module
A module is provided by React Native to detect what is the platform in which the app is running. This piece of functionality can be useful when only small parts of a component are platform specific.
var { Platform } = ReactNative; var styles = StyleSheet.create({ height: (Platform.OS === 'ios') ? 200 : 100, });
Platform.OS
will be ios
when running in iOS and android
when running in an Android device or simulator.
There is also a Platform.select
method available, that given an object containing Platform.OS as keys, returns the value for the platform you are currently running on.
var { Platform } = ReactNative; var styles = StyleSheet.create({ container: { flex: 1, ...Platform.select({ ios: { backgroundColor: 'red', }, android: { backgroundColor: 'blue', }, }), }, });
This will result in a container having flex: 1
on both platforms and backgroundColor - red on iOS and blue on Android.
Since it accepts any
value, you can also use it to return platform specific component, like below:
var Component = Platform.select({ ios: () => require('ComponentIOS'), android: () => require('ComponentAndroid'), })(); <Component />;
Detecting Android version
On Android, the Platform module can be also used to detect which is the version of the Android Platform in which the app is running
var {Platform} = ReactNative; if(Platform.Version === 21){ console.log('Running on Lollipop!'); }
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