KMPNotifier - Kotlin Multiplatform Push Notification

Simple and easy to use Kotlin Multiplatform Push Notification library (using Firebase Cloud Messaging) targeting ios and android.
This library is used in FindTravelNow production KMP project. You can check out Documentation for full library api information.

Features

• 🔔 Local and Push Notification (Firebase Cloud Messaging)
• 📱 Multiplatform (android and iOS)

Installation

Before starting you need to setup basic setup using Firebase official guideline (like initializing project in Firebase, adding google-services.json to android, GoogleService-Info.plist to iOS).

Minimum Requirements

• Android: minSdkVersion 21
• iOS: iOS 14.1

Gradle Setup

KMPNotifier is available on Maven Central. In your root project build.gradle.kts file (or settings.gradle file) add mavenCentral() to repositories, and add google-services plugin to plugins.

plugins {
  id("com.android.application") version "8.1.3" apply false
  id("org.jetbrains.kotlin.multiplatform") version "1.9.20" apply false
  id("com.google.gms.google-services") version "4.4.0" apply false
}

repositories { 
  mavenCentral()
}

Then in your shared module you add dependency in commonMain. Latest version: . In iOS framework part export this library as well.

sourceSets {
  commonMain.dependencies {
    api("io.github.mirzemehdi:kmpnotifier:<version>") // in iOS export this library
  }
}

And in androidApp build.gradle.kts file you apply google-services plugin

plugins {
  id("com.android.application")
  id("com.google.gms.google-services")
}

Platform Setup

In both platforms on Application Start you need to initialize library using

NotifierManager.initialize(NotificationPlatformConfiguration) //passing android or ios configuration depending on the platform

Android

Android Setup

class MyApplication : Application() {
   override fun onCreate() {
       super.onCreate()
       NotifierManager.initialize(
           configuration = NotificationPlatformConfiguration.Android(
               notificationIconResId = R.drawable.ic_launcher_foreground,
           )
       )
   }
}

Also starting from Android 13(API Level 33) you need to ask runtime POST_NOTIFICATIONS in activity. I created utility function that you can use in activity.

val permissionUtil by permissionUtil()
permissionUtil.askNotificationPermission() //this will ask permission in Android 13(API Level 33) or above, otherwise permission will be granted.

iOS

iOS Setup

First you just need to include FirebaseMessaging library to your ios app from Xcode. Then on application start you need to call both FirebaseApp initialization and NotifierManager initialization methods, and apnsToken setting as below. Don't forget to add Push Notifications and Background Modes (Remote Notifications) signing capability in Xcode.

import SwiftUI
import shared
import FirebaseCore
import FirebaseMessaging

class AppDelegate: NSObject, UIApplicationDelegate {

  func application(_ application: UIApplication,
                   didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {

      FirebaseApp.configure() //important
      NotifierManager.shared.initialize(configuration: NotificationPlatformConfigurationIos.shared)
      
    return true
  }

  func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        Messaging.messaging().apnsToken = deviceToken
  }
    
}

@main
struct iOSApp: App {
    
    @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate
    
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

Usage

You can send either local or push notification.

Local Notification

val notifier = NotifierManager.getLocalNotifier()
notifier.notify("Title", "Body")

Push Notification

Listen for push notification token changes

In this method you can send notification token to the server.

NotifierManager.addListener(object : NotifierManager.Listener {
  override fun onNewToken(token: String) {
    println("onNewToken: $token") //Update user token in the server if needed
  }
}) 

Receive data payload

NotifierManager.addListener(object : NotifierManager.Listener {
  override fun onPayloadData(data: PayloadData) {
    println("Push Notification payloadData: $data") //PayloadData is just typeAlias for Map<String,*>.
  }
}) 

And you need to call below platform-specific functions in order to receive payload data properly.

Android

Call NotifierManager.onCreateOrOnNewIntent(intent) on launcher Activity's onCreate and onNewIntent methods.

override fun onCreate(savedInstanceState: Bundle?) {
   super.onCreate(savedInstanceState)
      NotifierManager.onCreateOrOnNewIntent(intent)
      ...
    }

    override fun onNewIntent(intent: Intent?) {
        super.onNewIntent(intent)
        NotifierManager.onCreateOrOnNewIntent(intent)
    }

iOS

Call NotifierManager.onApplicationDidReceiveRemoteNotification(userInfo: userInfo) on application's didReceiveRemoteNotification method.

 func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any]) async -> UIBackgroundFetchResult {
      NotifierManager.shared.onApplicationDidReceiveRemoteNotification(userInfo: userInfo)
      return UIBackgroundFetchResult.newData
 }

Other functions

NotifierManager.getPushNotifier().getToken() //Get current user push notification token
NotifierManager.getPushNotifier().deleteMyToken() //Delete user's token for example when user logs out 
NotifierManager.getPushNotifier().subscribeToTopic("new_users") 
NotifierManager.getPushNotifier().unSubscribeFromTopic("new_users")