How to send a notification to specific platform?

Question

I want to send two different notifications to Android and iOS. I want to send a notification message to iOS, this way iOS displays a nice notification. For Android I want to send a data message, this way I can handle the notification on Android and also in the background (because I don't get a callback in the background and want to handle it myself).

I looked through the docs, but couldn't find anything about sending to a specific platform. How do I do that?

Also other suggestions on how to do this are welcome, but keep in mind that I specifically want to handle the notification myself through a callback on Android (onMessageReceived)

Answer 1

Update: A recent feature was added for FCM that gives an option to provide specific params for specific platforms, called Platform Overrides:

Customizing a message across platforms

Messages sent by the FCM v1 HTTP protocol can contain two types of JSON key pairs:

• a common set of keys to be interpreted by all app instances that receive the message.
• platform-specific blocks of keys interpreted only by app instances running on the specified platform.

Platform-specific blocks give you flexibility to customize messages for different platforms to ensure that they are handled correctly when received. In many scenarios, it makes sense to use both common keys and platform-specific keys in a given message.

When to use common keys

• Whenever you're targeting app instances on all platforms — iOS, Android, and web
• When you are sending messages to topics

The common keys that are interpreted by all app instances regardless of platform are message.notification.title, message.notification.body, and message.data.

When to use platform-specific keys

• When you want to send fields only to particular platforms
• To send platform-specific fields in addition to the common keys

Whenever you want to send values to specific platforms only, don't use common keys; use platform-specific key blocks. For example, to send a notification to only iOS and web but not Android, you must use two separate blocks of keys, one for iOS and one for web.

When you are sending messages with specific delivery options, use platform-specific keys to set them. You can specify different values per platform if you want; but even when you want to set essentially the same value across platforms, you must use platform-specific keys. This is because each platform may interpret the value slightly differently — for example, time-to-live is set on Android as an expiration time in seconds, while on iOS it is set as an expiration date.

Example: notification message with platform-specific delivery options

The following v1 send request sends a common notification title and content to all platforms, but also sends some platform-specific overrides. Specifically, the request:

• sets a long time-to-live for Android and Web platforms, while setting the APNs (iOS) message priority to a low setting
• sets the appropriate keys to define the result of a user tap on the notification on Android and iOS — click_action, and category, respectively.

{
  "message":{
     "token":"bk3RNwTe3H0:CI2k_HHwgIpoDKCIZvvDMExUdFQ3P1...",
     "notification":{
       "title":"Match update",
       "body":"Arsenal goal in added time, score is now 3-0"
     },
     "android":{
       "ttl":"86400s",
       "notification"{
         "click_action":"OPEN_ACTIVITY_1"
       }
     },
     "apns": {
       "headers": {
         "apns-priority": "5",
       },
       "payload": {
         "aps": {
           "category": "NEW_MESSAGE_CATEGORY"
         }
       }
     },
     "webpush":{
       "headers":{
         "TTL":"86400"
       }
     }
   }
 }

See the HTTP v1 reference documentation for complete detail on the keys available in platform-specific blocks in the message body. For more information about building send requests that contain the message body, see Build Send Requests.

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I remember answering a similar question before but cant seem to find it. There is currently no option to specify which platform a message would be sent. The simplest way you could do this is by using Topics Messaging.

Everytime the token is generated for the first time, you determine from your client app the Platform type and subscribe them to the corresponding topic (e.g. topics/(Android/iOS)_<Your App Name>), then sned the messages as needed.

It's also good to keep track of the registration tokens from your Server, if you're using Firebase DB, you could put them inside a node:

/pushTokens
  /android
    /{userId} : string
  /ios
    /{userid}: string

This would let you check from your backend side and adjust your payload as needed when sending single messages.

Answer 2

I was facing same issue with Android Development. We used Laravel on backend side. On backend side, developer has to maintain different scenario for both platforms.

In Android :

FCM::sendTo($tokens, $option, null, $data);

Here, null is passed as a notification builder. When you pass null in notification and create databuilder($data), you can receive message in onMessageReceived method when app in background.

For iOS :

FCM::sendTo($tokens, $option, $notification, $data);

Here, you can pass notification builder in $notification. So, iOS device can also get notification.