Foreground & Background Push Notification Using Firebase, React Native & Expo

Firebase Cloud Messaging (FCM) & React Native. JavaScript Code

FCM with react native and expo

Project setup, Package Requirements, and Code

npm install --save @react-native-firebase/app
npm install --save @react-native-firebase/messaging
  • We need a few more packages. But for now, let’s settle with these two. Next, In App.js, copy and paste the required code from the official documented site.
const requestUserPermission = async () => {
const authStatus = await messaging().requestPermission();
const enabled =
authStatus === messaging.AuthorizationStatus.AUTHORIZED ||
authStatus === messaging.AuthorizationStatus.PROVISIONAL;

if (enabled) {
console.log('Authorization status:', authStatus);
}
}
  • We will use the useEffect hook to remember the states of the push notification
useEffect(() => {
if (requestUserPermission){
// return fcm token for the device
messaging().getToken().then(token => {
console.log(token);
});
}
else {
console.log("Failed Token Status", authStatus);
}
}, [])
  • Check whether an initial notification is available. Place the below code snippet inside the useEffect hook.
messaging()
.getInitialNotification()
.then(remoteMessage => {
if (remoteMessage) {
console.log(
'Notification caused app to open from quit state:',
remoteMessage.notification,
);
}
});
  • Assume a message notification contains a “type” property in the data payload of the screen to open. Place the below code also inside the useEffect hook.
messaging().onNotificationOpenedApp(remoteMessage => {
console.log(
'Notification caused app to open from background state:',
remoteMessage.notification,
);
});
  • Now, at last, register a background handler inside the useEffect hook.
messaging().setBackgroundMessageHandler(async remoteMessage => {
console.log('Message handled in the background!', remoteMessage);
});
  • Call the onMessage method inside your application code to listen to messages in the foreground. Code executed via this handler has access to React context and can interact with your application (e.g. updating the state or UI).
const unsubscribe = messaging().onMessage(async remoteMessage => {
Alert.alert('A new FCM message arrived!', JSON.stringify(remoteMessage));
});

return unsubscribe;
}, []);
  • For now, we don’t need any extra code. Yeah, you can customize your application according to the requirements. But, This is the basic code of the Push Notification from the background and foreground state of the application Using Firebase cloud messaging, react native, and expo.
  • Next, you must install the expo dev client package of the react native expo. Why? Because we just used the native code of the react-native. So, we can’t test our application in the expo go mobile application. If you are an expo user, then you can use either the Prebuild method or the Development build method. I prefer to use the Development build method because it’s easy to use, developer-friendly, and does not require Android Studio to run.
  • I am setting up my firebase application for Android because I will test this application on my Android device.
  • Sometimes the Development build fails due to the internal server issue. You just have to retry the command
  • If you are confused or lost, I would recommend watching a step-by-step video tutorial. Few minutes of setup and you will be ready to test the application.

Why do I suggest watching more videos?

I am from India and I love writing code and sharing it with the community. We all know that money is the ultimate motivation for work, and the Medium payment system uses Stripe, which has been in preview mode in India for the past 4–5 years. I waited a year on the Medium platform, but in the end, nothing worked out.

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