Firebase messaging-handle background message in kotlin

Question

I'm using firebase_messaging in my flutter application. To handle background messages with firebase messaging in pub they suggested to create new Application.java file and replace java file name in AndroidManifest file.

In my application i'm using kotlin and i already implemented some native code in MainActivity.kt

So how to write this code in kotlin.

package io.flutter.plugins.firebasemessagingexample;

import io.flutter.app.FlutterApplication;
import io.flutter.plugin.common.PluginRegistry;
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback;
import io.flutter.plugins.GeneratedPluginRegistrant;
import io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService;

public class Application extends FlutterApplication implements PluginRegistrantCallback {
 @Override
public void onCreate() {
 super.onCreate();
 FlutterFirebaseMessagingService.setPluginRegistrant(this);
 }

@Override
public void registerWith(PluginRegistry registry) {
 GeneratedPluginRegistrant.registerWith(registry);
}
}

it is mandatory to replace MainActivity to Application in AndroidManifest file?

Answer 1

Here is the Kotlin code for the new firebase cloud messaging version:

package id.your.app
    
import io.flutter.app.FlutterApplication
import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback
import io.flutter.plugins.firebase.messaging.FlutterFirebaseMessagingBackgroundService
// import io.flutter.plugins.firebase.messaging.FlutterFirebaseMessagingPlugin

class Application : FlutterApplication(), PluginRegistrantCallback {
  override fun onCreate() {
    super.onCreate()
    FlutterFirebaseMessagingBackgroundService.setPluginRegistrant(this)
  }

  override fun registerWith(registry: PluginRegistry?) {
    // FlutterFirebaseMessagingPlugin.registerWith(registry?.registrarFor("io.flutter.plugins.firebase.messaging.FlutterFirebaseMessagingPlugin"))
  }
}

Answer 2

Here is the working background notification kotlin code:

package com.example.yourapp

import io.flutter.app.FlutterApplication
import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback
import io.flutter.plugins.GeneratedPluginRegistrant
import io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService

class Application : FlutterApplication(), PluginRegistrantCallback {

    override fun onCreate() {
        super.onCreate()
        FlutterFirebaseMessagingService.setPluginRegistrant(this);
    }

    override fun registerWith(registry: PluginRegistry?) {
        io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin.registerWith(registry?.registrarFor("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin"));
    }
}