当应用程序在后台时更新Firebase推送通知

Question

How to update a Firebase push notification containing data payload when the app is in background? Is there a way to specify the notification id in the notification to the Firebase API?

My request json to the firebase api.

{
"registration_ids": ["device id"], 
"collapse_key": "Updates Available"
"notification": {
                    "title": "title", 
                    "desc": "description",
                    "body": "Message received", 
                    "sound": "TYPE_NOTIFICATION",
                    "click_action": "sometargetAction"
                },
"data":         {
                    "user": 
                    {
                        "id": 2
                        "name":"leapingwolf", 
                        "occupation": "passionate coder"
                    }
                }
}

I use the id of the "user" to append to a delivered push notification when the app is in foreground in the onMessageReceived function like so

        User user = remoteMessage.getData().get("user");
        Gson gson = new GsonBuilder().create();
        User userModel =  gson.fromJson(user, User.class);
        Uri defaultSoundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
                .setContentTitle("FCM Message With Payload")
                .setContentText(messageBody)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setAutoCancel(true)
                .setSound(defaultSoundUri)
                .setContentIntent(pendingIntent);

        NotificationManager notificationManager =
                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

        notificationManager.notify(userModel.getId(), notificationBuilder.build());

The full project is in github https://github.com/akshatashan/FirebaseCloudMessagingDemo

Answer 1

I figured out the solution based on the answers posted in the link How to handle notification when app in background in Firebase

To summarise, if the request json does not have the notification tag, then onMessageReceived is called irrespective of whether or not the app is in background. Send all relevant field in the data tag and parse it in the onMessageReceived.

Answer 2

I think what you are looking for is Collapsible Messages :

A collapsible message is a message that may be replaced by a new message containing the same collapse key if it has yet to be delivered to the device.

For both message types (notification and data), it seems they can be both set as collapsible , in your case, you were asking for the data payload:

Data message

• Client app is responsible for processing data messages. Data messages have only custom key-value pairs.
• Use your app server and FCM server API: Set the data key only. Can be either collapsible or non-collapsible .

So to put it simply, you just have to make use of the collapse_key accordingly:

This parameter identifies a group of messages (eg, with collapse_key: "Updates Available" ) that can be collapsed, so that only the last message gets sent when delivery can be resumed. This is intended to avoid sending too many of the same messages when the device comes back online or becomes active.

Note that there is no guarantee of the order in which messages get sent.

Note: A maximum of 4 different collapse keys is allowed at any given time. This means a FCM connection server can simultaneously store 4 different send-to-sync messages per client app. If you exceed this number, there is no guarantee which 4 collapse keys the FCM connection server will keep.