Handling Android Back Button Press in React Native

Handling Android Back Button Press in React Native

When the user presses the Android hardware back button in React Native, react-navigation will pop a screen or exit the app if there are no screens to pop. This is the sensible default behavior, but there are situations when you might want to implement custom handling. This is where handling android back button is useful. You can also check react-navigation-backhandler library to handle the back press.

To handle the Android Back Button Press in the react native we have to register the hardwareBackPress event listener with a callback function, which will be called after pressing the Back Button. We should also remove the listener when we are jumping out from the screen (where we have added the listener) because sometime after going to the next screen or any other screen the listener remains active in the background if the last screen is in the stack and not killed by the system.

The event subscriptions are called in reverse order (i.e. last registered subscription first), and if one subscription returns true then subscriptions registered earlier will not be called. 

1. Add the hardwareBackPress using

2. Remove the hardwareBackPress using

3. To handle the event we have used the function handleBackButtonClick.

Returning true from handleBackButtonClick denotes that we have handled the event, and react-navigation’s listener will not get called, thus not popping the screen. Returning false will cause the event to bubble up and react-navigation’s listener will pop the screen.

Why not use component lifecycle methods?

At first, you may be inclined to use componentDidMount to subscribe for the back press event and componentWillUnmount to unsubscribe. The reason, why we do not use them, is that they are not generally called when entering or leaving a screen.

More specifically, consider a StackNavigator with screens A and B. After navigating to A, its componentDidMount is called. When pushing B, its componentDidMount is also called, but A remains mounted and its componentWillUnmount is therefore not called.

Similarly, when going back from B to AcomponentWillUnmount of B is called, but componentDidMount of A is not because A remained mounted the whole time.

So here was the big discussion. Now Let’s start with the code.

In our example, we are going from FirstPage to SecondPage using navigate and after clicking Back Button on SecondPage we will navigate to ThirdPage with an alert. We have also used this.props.navigation.goBack(null); on ThirdPage to popup the default screen. So let’s get started.

To Make a React Native App

Getting started with React Native will help you to know more about the way you can make a React Native project. We are going to use react-native init to make our React Native App. Assuming that you have node installed, you can use npm to install the react-native-cli command line utility. Open the terminal and go to the workspace and run

npm install -g react-native-cli

Run the following commands to create a new React Native project

react-native init ProjectName

If you want to start a new project with a specific React Native version, you can use the --version argument:

react-native init ProjectName --version X.XX.X
react-native init ProjectName --version react-native@next

This will make a project structure with an index file named App.js in your project directory.

Installation of Dependencies

To use createStackNavigator you need to install react-navigation and react-native-gesture-handler dependencies.

To install these dependencies open the terminal and jump into your project

Run the following commands

This command will copy all the dependencies into your node_module directory. –save is optional, it is just to update dependencies in your package.json file.

CocoaPods Installation

After the updation of React Native 0.60, they have introduced autolinking so we do not require to link the library but need to install pods. So to install pods use

Project File Structure

To start with this Example you need to create a directory named pages in your project and create three files FirstPge.js, SecondPage.js, and ThirdPage.js.

Now Open App.js in any code editor and replace the code with the following code.

App.js

Open pages/FirstPage.js in any code editor and replace the code with the following code.

FirstPage.js

Open pages/SecondPage.js in any code editor and replace the code with the following code.

SecondPage.js

Open pages/ThirdPage.js in any code editor and replace the code with the following code.

ThirdPage.js

To Run the React Native App

Open the terminal again and jump into your project using.
cd ProjectName
To run the project on an Android Virtual Device or on real debugging device
react-native run-android
or on the iOS Simulator by running
react-native run-ios (macOS only).

That was the way to handle the Android Back Button. If you have any doubt or you want to share something about the topic you can comment below or contact us here. There will be more posts coming soon. Stay tuned!

Hope you liked it. 🙂

2 thoughts on “Handling Android Back Button Press in React Native”

  1. you can set condition for costume function that u write for hardware button , for example when ( for example for React Native Router Flux ) Actions.currentScene === ‘Home’ do something or other conditions u want .

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