How I can specify the priority on FCM message?

Question

I'm using react-native-firebase to manage notifications on React-native app. I try to handle FCM message on the background when application is off without display the notification.

I’m using react-native-firebase to manage notifications on React-native app. When my app is off, I try to catch FCM messages and wake up my app without displaying any notification, just as described here https://rnfirebase.io/docs/v4.2.x/messaging/introduction#Data-only-messages 1.

In React Native Firebase doc, they say :

You will need to specify the FCM message priority as high for this functionality to work. If this isn’t set, the app is not given permission to launch the background message handler.

Where I must specify this priority ? I don’t understand how this works.

Edit 1 : I tried to set priority : "high"on FCM message but it's still not working. I have the same problem related to this issue : https://github.com/invertase/react-native-firebase/issues/500

Answer 1

The priority is considered as a platform specific config. You can set different priorities for different platforms.

For instance look at the example below: (Message priority in Fcm docs)

{
  "message":{
    "topic":"subscriber-updates",
    "notification":{
      "body" : "This week's edition is now available.",
      "title" : "NewsMagazine.com",
    },
    "data" : {
      "volume" : "3.21.15",
      "contents" : "http://www.news-magazine.com/world-week/21659772"
    },
    "android":{
      "priority":"normal"
    },
    "apns":{
      "headers":{
        "apns-priority":"5"
      }
    },
    "webpush": {
      "headers": {
        "Urgency": "high"
      }
    }
  }
}

Answer 2

Using "priority":10 did the trick for me.

curl -X POST --header "Authorization: key=<your_key>" --Header "Content-Type: application/json" https://fcm.googleapis.com/fcm/send -d  {"data":{"body":"Test body from curl"},"registration_ids":["<reg_ids>"],"apns":{"headers":{"apns-priority":"10"}},"webpush":{"headers":{"Urgency": "high"}},"android":{"priority":"high"},"priority":10}