April 2018
Intermediate to advanced
284 pages
6h 43m
English
Using FCM, you can send two types of messages to the clients: Notification Messages and Data Messages. The maximum payload size for both kinds of messages is 4 KB when using Firebase SDK. However, when you send messages from the Firebase console, it enforces a 1024 character limit.
The notification messages are handled by FCM SDK automatically, since they are just display messages. You can use notification messages when you want FCM to display a notification on your client app's behalf. Notification messages contain a predefined set of keys and can also contain an optional data payload.
The notification message object looks like this:
{ "message":{ "token":"bk3RNwTe3H0:CI2k_HHwgIpoDKCIZvvDMExUdFQ3P1...", "notification":{ "title":"This ...