Firebase Cloud Messaging (FCM) delivers push notification to iOS devices via Apple's Push Notifications service. Also FCM extends functionality of push notifications.
How FCM extends?
- FCM works with iOS and Android. Cool feature if you have the app for both platforms;
- Don't need to develop backend for sending notifications, storing pn tokens etc. Just register your app in the Google Developer Console and follow User Guides. For sending a push just execute request to
https://fcm.googleapis.com/fcm/send
with params;
- Broadcast notifications. The app subscribes to a
topic
and then you can send a notification to all topic
subscribers. Very cool;
- Upstream messages (send data to the server)
Also Google has others services you can extend FCM with. For example Cloud Functions.
I didn't find that FCM integration take big affect to battery life in my apps.
UPDATE:
FCM framework sends push notification token (and other info) to Google services. Also as I mentioned above you can subscribe app for a specific topic
. Than Google knows which device needs to send a push to.
There is a possibility to setup FCM in iOS automatically(with using method swizzling). FCM exchange AppDelegate
methods and knows your's device pn token.