Android Notifications

Priority: P2 (OPTIONAL)

Push notifications using Firebase Cloud Messaging.

Implementation Guidelines

• Channels: Create NotificationChannel with a unique ID (required for API 26+). Notifications without a valid channel are silently dropped. Use NotificationCompat for backwards compatibility.
• Permissions: Explicitly request POST_NOTIFICATIONS on Android 13+ (API 33). Avoid requesting system permission on app launch; show a priming dialog first to explain the benefit.
• Service: Implement FirebaseMessagingService with onMessageReceived and onNewToken for background push handling. Declare the service in AndroidManifest with the MESSAGING_EVENT intent action.
• Flow: Handle notification taps in both onCreate and onNewIntent using PendingIntent. Pass data between activities via Intent extras.
• Payload: Limit the notification payload to essential IDs. Perform background data fetching via WorkManager if more data is needed.

Anti-Patterns

• No Missing Channel: Notifications fail silently without channels on API 26+.
• No Unconditional Requests: Don't spam permission dialog on first launch.
• No Missing Manifest: Service must be declared with MESSAGING_EVENT action.

References

• Implementation Details