The Project | About Us | Contribute | Donations | License

HOME

In this section, we will explore how to handle notifications in a Firebase-enabled application. Handling notifications effectively ensures that users receive timely and relevant information, enhancing their overall experience with your app.

Key Concepts

Notification Types:
- Foreground Notifications: Notifications received while the app is in the foreground.
- Background Notifications: Notifications received while the app is in the background or closed.
Notification Payload:
- Notification Messages: Automatically displayed by the device's system UI.
- Data Messages: Handled by the app's code, providing more flexibility.
Notification Channels (Android only): Used to categorize notifications and manage their behavior.

Handling Foreground Notifications

When your app is in the foreground, you need to handle notifications manually to display them to the user. This can be done using Firebase Cloud Messaging (FCM) service.

Example: Handling Foreground Notifications in Android

public class MyFirebaseMessagingService extends FirebaseMessagingService {

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        // Check if the message contains a notification payload.
        if (remoteMessage.getNotification() != null) {
            // Display the notification
            showNotification(remoteMessage.getNotification().getTitle(), remoteMessage.getNotification().getBody());
        }

        // Check if the message contains a data payload.
        if (remoteMessage.getData().size() > 0) {
            // Handle the data message
            handleDataMessage(remoteMessage.getData());
        }
    }

    private void showNotification(String title, String messageBody) {
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, "default_channel_id")
                .setSmallIcon(R.drawable.ic_notification)
                .setContentTitle(title)
                .setContentText(messageBody)
                .setAutoCancel(true)
                .setPriority(NotificationCompat.PRIORITY_HIGH);

        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify(0, notificationBuilder.build());
    }

    private void handleDataMessage(Map<String, String> data) {
        // Process the data message
    }
}

Explanation

onMessageReceived: This method is called when a message is received. It checks if the message contains a notification payload or a data payload.
showNotification: This method creates and displays a notification using the NotificationCompat.Builder.
handleDataMessage: This method processes the data payload.

Handling Background Notifications

When your app is in the background, the system automatically handles notification messages and displays them in the notification tray. However, data messages need to be handled by your app.

Example: Handling Background Notifications in Android

public class MyFirebaseMessagingService extends FirebaseMessagingService {

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        // Check if the message contains a data payload.
        if (remoteMessage.getData().size() > 0) {
            handleDataMessage(remoteMessage.getData());
        }
    }

    private void handleDataMessage(Map<String, String> data) {
        // Process the data message
        // For example, you can create a notification based on the data
        String title = data.get("title");
        String messageBody = data.get("body");
        showNotification(title, messageBody);
    }

    private void showNotification(String title, String messageBody) {
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, "default_channel_id")
                .setSmallIcon(R.drawable.ic_notification)
                .setContentTitle(title)
                .setContentText(messageBody)
                .setAutoCancel(true)
                .setPriority(NotificationCompat.PRIORITY_HIGH);

        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify(0, notificationBuilder.build());
    }
}

Explanation

onMessageReceived: This method is called when a message is received. It checks if the message contains a data payload.
handleDataMessage: This method processes the data payload and creates a notification based on the data.

Notification Channels (Android Only)

Starting from Android 8.0 (API level 26), all notifications must be assigned to a channel. This allows users to manage notification settings for each channel.

Example: Creating a Notification Channel

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
    NotificationChannel channel = new NotificationChannel("default_channel_id",
            "Default Channel",
            NotificationManager.IMPORTANCE_HIGH);
    channel.setDescription("This is the default channel for notifications");

    NotificationManager notificationManager = getSystemService(NotificationManager.class);
    notificationManager.createNotificationChannel(channel);
}

Explanation

NotificationChannel: This class represents a notification channel.
createNotificationChannel: This method creates the notification channel.

Practical Exercise

Task

Create a Firebase project and set up Firebase Cloud Messaging.
Implement a service to handle notifications in your Android app.
Create a notification channel for your notifications.
Test sending notifications from the Firebase console.

Solution

Create a Firebase Project:
- Go to the Firebase Console.
- Click on "Add project" and follow the instructions.
Set Up Firebase Cloud Messaging:
- Add Firebase to your Android project.
- Add the necessary dependencies in your build.gradle file.
Implement the Service:
- Create a class that extends FirebaseMessagingService.
- Override the onMessageReceived method to handle notifications.
Create a Notification Channel:
- In your FirebaseMessagingService class, create a notification channel in the onCreate method.
Test Sending Notifications:
- Go to the Firebase Console.
- Navigate to Cloud Messaging.
- Send a test notification to your app.

Common Mistakes and Tips

Missing Notification Channel: Ensure you create a notification channel for Android 8.0 and above.
Handling Data Messages: Always check if the message contains a data payload and handle it appropriately.
Foreground Notifications: Remember to manually display notifications when the app is in the foreground.

Conclusion

In this section, we covered how to handle notifications in a Firebase-enabled application. We discussed the different types of notifications, how to handle them in both foreground and background states, and how to create notification channels for Android. By following the examples and completing the practical exercise, you should now be able to effectively manage notifications in your app.

Handling Notifications

Key Concepts

Handling Foreground Notifications

Example: Handling Foreground Notifications in Android

Explanation

Handling Background Notifications

Example: Handling Background Notifications in Android

Explanation

Notification Channels (Android Only)

Example: Creating a Notification Channel

Explanation

Practical Exercise

Task

Solution

Common Mistakes and Tips

Conclusion

Firebase Course

Module 1: Introduction to Firebase

Module 2: Firebase Authentication

Module 3: Firebase Realtime Database

Module 4: Cloud Firestore

Module 5: Firebase Storage

Module 6: Firebase Cloud Messaging

Module 7: Firebase Analytics

Module 8: Firebase Functions

Module 9: Firebase Performance Monitoring

Module 10: Firebase Test Lab

Module 11: Advanced Firebase Topics