Firebase Cloud Messaging is a cross-platform messaging solution that allows sending messages at no cost. It supports notifications or data messages up to 4KB in size and versatile targeting. Notifications are displayed to the user, while data messages are received in the background. FCM supports notification payloads for display and click actions, as well as custom data payloads. Proper handling of notifications in the foreground and background is required. Token management and missing notifications can be issues to address. Capabilities vary across platforms for notifications, permissions, and upstream messaging.

1. MASTERING FIREBASE
CLOUD MESSAGING
@Miqubel
by Miquel Beltran
Android Developer @ Nebenan.de

2. “cross-platform messaging solution
that lets you reliably deliver messages
at no cost.”
What is Firebase Cloud Messaging?
@Miqubel

3. Key capabilities:
• Notifications or Data messages (4KB)
• Versatile targeting
• Upstream messages
@Miqubel

4. @Miqubel
Notification vs. Message
• Push Notification?
• Notification?
• Cloud Message?

5. The idea
@Miqubel

6. The reality
@Miqubel

7. Notifications console
@Miqubel

8. A/B Testing with the console
• Presented at Firebase Dev Submit 2017
• Multiple audience target
• Different content / parameters
• Check results per audience
@Miqubel

9. @Miqubel

10. Pushing manually
curl https://fcm.googleapis.com/fcm/send -X POST
--header "Authorization: key=long auth key"
--Header "Content-Type: application/json"
-d '
{
"to": "the device token"
"notification":{
"title":"New Notification!",
"body":"Test"
},
"priority":10
}'
val token = FirebaseInstanceId.getInstance().token
Log.d("Firebase", "My token: $token")
@Miqubel

11. Token problem
• Where to store the token?
• More than one token per user?
• What happens when the user logs out?
• Keep sending emails?
@Miqubel

12. Notification vs. Data
@Miqubel

13. Notifications in foreground
class NotificationService : FirebaseMessagingService() {
override fun onMessageReceived(remoteMessage: RemoteMessage) {
val notification = NotificationCompat.Builder(this,”cid")
.setContentTitle(remoteMessage.notification.title)
.setContentText(remoteMessage.notification.body)
.setSmallIcon(R.mipmap.ic_launcher)
.build()
val manager = NotificationManager…
manager.notify(123, notification)
}
}
@Miqubel

14. Notification Payload
• “icon”: Android & iOS
• “sound”: only Android
• “badge”: only iOS
• “click_action”: Android & iOS
"notification":{
"title": "New Notification!",
"body": "Test"
},
@Miqubel

15. Notifications & Click Actions
"notification":{
"title": "New Notification!",
"body": "Test",
"click_action": "OPEN_FRIEND_LIST"
},
@Miqubel
<intent-filter>
<action android:name=“OPEN_FRIEND_LIST” />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>

16. Data Payload
“notification":{
"title": "New Notification!",
"body": “Test"
},
@Miqubel

17. Data Payload
"data":{
"title": "New Notification!",
"body": “Test"
},
@Miqubel

18. Data Payload
"data":{
"title": "New Notification!",
"body": "Test",
"user_id": "1234",
"user_avatar": "http://example.com/users/1234/avatar.jpg",
"notification_type": "private_message"
},
@Miqubel

19. Notifications with data
class NotificationService : FirebaseMessagingService() {
override fun onMessageReceived(remoteMessage: RemoteMessage) {
val notification = NotificationCompat.Builder(this,”cid")
.setContentTitle(remoteMessage.data["title"])
.setContentText(remoteMessage.data["body"])
.setSmallIcon(R.mipmap.ic_launcher)
.build()
val manager = NotificationManager…
manager.notify(123, notification)
}
}
@Miqubel

20. Missing Notifications?
“The reason is that phone manufacturers
like Oppo, Xiaomi, and One Plus use a stock
ROM that disables the re-starting of
background services for most
apps.”
Neil Mathew: Why your Push Notifications
never see the light of day
@Miqubel

21. Web: Asking permission
messaging.requestPermission()
@Miqubel

22. @Miqubel

23. Web: Notification vs Data
@Miqubel

24. Web: Service Worker?
@Miqubel

25. Web Alternative
• Fallback that supports all browsers
• Not free
• No background work
• Focused on data transport, not
notifications
• No need to request permissions
@Miqubel

26. iOS: all Apple
• Setup APNs (Apple Push Notification service)
• No difference between pure data vs. notifications
• Specific parameters just for iOS too
• “Just works”™
@Miqubel

27. Upstream messages
• Android & iOS: send “upstream” messages to your
server
• API missing on web?
• Asynchronous and battery efficient
@Miqubel

28. “One size fits no one”
- probably me
@Miqubel

29. Thank you!
- also me
@Miqubel