sample implementation of registration tokens for FCM

messaging/app/build.gradle

@@ -48,6 +48,7 @@ dependencies {
     implementation 'androidx.annotation:annotation:1.5.0'
     implementation 'androidx.vectordrawable:vectordrawable-animated:1.1.0'
     implementation 'androidx.core:core-ktx:1.9.0'
+    implementation 'androidx.work:work-runtime-ktx:2.8.0'
 
     // Required when asking for permission to post notifications (starting in Android 13)
     implementation 'androidx.activity:activity-ktx:1.6.1'
@@ -70,8 +71,14 @@ dependencies {
 
     implementation 'com.google.firebase:firebase-installations-ktx:17.1.0'
 
+    // Used to store FCM registration tokens
+    implementation 'com.google.firebase:firebase-firestore-ktx:24.1.0'
+
     implementation 'androidx.work:work-runtime:2.7.1'
 
+    // Used for Firestore
+    implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.4.0'
+
     // Testing dependencies
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
     androidTestImplementation 'androidx.test:runner:1.5.2'

messaging/app/src/main/java/com/google/firebase/quickstart/fcm/kotlin/MainActivity.kt

@@ -3,6 +3,7 @@ package com.google.firebase.quickstart.fcm.kotlin
 import android.Manifest
 import android.app.NotificationChannel
 import android.app.NotificationManager
+import android.content.Context
 import android.content.pm.PackageManager
 import android.os.Build
 import android.os.Bundle
@@ -11,11 +12,22 @@ import android.widget.Toast
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.content.ContextCompat
-import com.google.android.gms.tasks.OnCompleteListener
+import androidx.lifecycle.lifecycleScope
+import androidx.work.ExistingPeriodicWorkPolicy
+import androidx.work.PeriodicWorkRequestBuilder
+import androidx.work.WorkManager
+import com.google.firebase.Timestamp
+import com.google.firebase.firestore.FieldValue
+import com.google.firebase.firestore.ktx.firestore
 import com.google.firebase.ktx.Firebase
 import com.google.firebase.messaging.ktx.messaging
 import com.google.firebase.quickstart.fcm.R
 import com.google.firebase.quickstart.fcm.databinding.ActivityMainBinding
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.tasks.await
+import java.util.Calendar
+import java.util.Date
+import java.util.concurrent.TimeUnit
 
 class MainActivity : AppCompatActivity() {
 
@@ -79,26 +91,25 @@ class MainActivity : AppCompatActivity() {
 
         binding.logTokenButton.setOnClickListener {
             // Get token
-            // [START log_reg_token]
-            Firebase.messaging.getToken().addOnCompleteListener(OnCompleteListener { task ->
-                if (!task.isSuccessful) {
-                    Log.w(TAG, "Fetching FCM registration token failed", task.exception)
-                    return@OnCompleteListener
-                }
-
+            lifecycleScope.launch {
                 // Get new FCM registration token
-                val token = task.result
-
+                val token = getAndStoreRegToken()
                 // Log and toast
                 val msg = getString(R.string.msg_token_fmt, token)
                 Log.d(TAG, msg)
                 Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT).show()
-            })
-            // [END log_reg_token]
+            }
         }
 
         Toast.makeText(this, "See README for setup instructions", Toast.LENGTH_SHORT).show()
         askNotificationPermission()
+
+        // Refresh token and send to server every month
+        val saveRequest =
+            PeriodicWorkRequestBuilder<UpdateTokenWorker>(730, TimeUnit.HOURS)
+                .build()
+
+        WorkManager.getInstance(this).enqueueUniquePeriodicWork("saveRequest", ExistingPeriodicWorkPolicy.UPDATE, saveRequest);
     }
 
     private fun askNotificationPermission() {
@@ -115,8 +126,39 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
+    private suspend fun getAndStoreRegToken(): String {
+        // [START log_reg_token]
+        var token = Firebase.messaging.token.await()
+
+        // Check whether the retrieved token matches the one on your server for this user's device
+        val preferences = this.getPreferences(Context.MODE_PRIVATE)
+        val tokenStored = preferences.getString("deviceToken", "")
+        lifecycleScope.launch {
+            if (tokenStored == "" || tokenStored != token)
+            {
+                // If you have your own server, call API to send the above token and Date() for this user's device
+
+                // Example shown below with Firestore
+                // Add token and timestamp to Firestore for this user
+                val deviceToken = hashMapOf(
+                    "token" to token,
+                    "timestamp" to FieldValue.serverTimestamp(),
+                )
+
+                // Get user ID from Firebase Auth or your own server
+                Firebase.firestore.collection("fcmTokens").document("myuserid")
+                    .set(deviceToken).await()
+            }
+        }
+
+        // [END log_reg_token]
+        Log.d(TAG, "got token: $token")
+
+        return token
+    }
+
     companion object {
 
-        private const val TAG = "MainActivity"
+        private const val TAG = "MainActivityandreawu"
     }
 }

messaging/app/src/main/java/com/google/firebase/quickstart/fcm/kotlin/MyFirebaseMessagingService.kt

@@ -7,13 +7,19 @@ import android.content.Context
 import android.content.Intent
 import android.media.RingtoneManager
 import android.os.Build
+import android.preference.PreferenceManager
 import android.util.Log
 import androidx.core.app.NotificationCompat
 import androidx.work.OneTimeWorkRequest
 import androidx.work.WorkManager
+import com.google.firebase.firestore.FieldValue
+import com.google.firebase.firestore.ktx.firestore
+import com.google.firebase.ktx.Firebase
 import com.google.firebase.messaging.FirebaseMessagingService
 import com.google.firebase.messaging.RemoteMessage
 import com.google.firebase.quickstart.fcm.R
+import java.util.*
+
 
 class MyFirebaseMessagingService : FirebaseMessagingService() {
 
@@ -74,7 +80,7 @@ class MyFirebaseMessagingService : FirebaseMessagingService() {
         // If you want to send messages to this application instance or
         // manage this apps subscriptions on the server side, send the
         // FCM registration token to your app server.
-        sendRegistrationToServer(token)
+        sendTokenToServer(token)
     }
     // [END on_new_token]
 
@@ -95,6 +101,7 @@ class MyFirebaseMessagingService : FirebaseMessagingService() {
         Log.d(TAG, "Short lived task is done.")
     }
 
+    // [START send_token_to_server]
     /**
      * Persist token to third-party servers.
      *
@@ -103,10 +110,20 @@ class MyFirebaseMessagingService : FirebaseMessagingService() {
      *
      * @param token The new token.
      */
-    private fun sendRegistrationToServer(token: String?) {
-        // TODO: Implement this method to send token to your app server.
-        Log.d(TAG, "sendRegistrationTokenToServer($token)")
+    private fun sendTokenToServer(token: String?) {
+        // If you're running your own server, call API to send token and today's date for the user
+
+        // Example shown below with Firestore
+        // Add token and timestamp to Firestore for this user
+        val deviceToken = hashMapOf(
+            "token" to token,
+            "timestamp" to FieldValue.serverTimestamp(),
+        )
+        // Get user ID from Firebase Auth or your own server
+        Firebase.firestore.collection("fcmTokens").document("myuserid")
+            .set(deviceToken)
     }
+    // [END send_token_to_server]
 
     /**
      * Create and show a simple notification containing the received FCM message.

messaging/app/src/main/java/com/google/firebase/quickstart/fcm/kotlin/UpdateTokenWorker.kt

@@ -0,0 +1,35 @@
+package com.google.firebase.quickstart.fcm.kotlin
+
+import android.content.Context
+import androidx.work.CoroutineWorker
+import androidx.work.WorkerParameters
+import com.google.firebase.firestore.FieldValue
+import com.google.firebase.firestore.ktx.firestore
+import com.google.firebase.ktx.Firebase
+import com.google.firebase.messaging.ktx.messaging
+import kotlinx.coroutines.tasks.await
+
+class UpdateTokenWorker(appContext: Context, workerParams: WorkerParameters):
+    CoroutineWorker(appContext, workerParams) {
+
+    override suspend fun doWork(): Result {
+        // Refresh the token and send it to your server
+        var token = Firebase.messaging.token.await()
+
+        // If you have your own server, call API to send the above token and Date() for this user's device
+
+        // Example shown below with Firestore
+        // Add token and timestamp to Firestore for this user
+        val deviceToken = hashMapOf(
+            "token" to token,
+            "timestamp" to FieldValue.serverTimestamp(),
+        )
+
+        // Get user ID from Firebase Auth or your own server
+        Firebase.firestore.collection("fcmTokens").document("myuserid")
+            .set(deviceToken).await()
+
+        // Indicate whether the work finished successfully with the Result
+        return Result.success()
+    }
+}

messaging/functions/index.js

@@ -0,0 +1,26 @@
+'use strict';
+
+const functions = require('firebase-functions');
+const admin = require('firebase-admin');
+
+admin.initializeApp();
+
+const EXPIRATION_TIME = 1000 * 60 * 60 * 24 * 60; // 60 days
+
+/**
+ * Scheduled function that runs once a day. It retrieves all stale tokens then
+ * unsubscribes them from 'topic1' then deletes them.
+ *
+ * Note: weather is an example topic here. It is up to the developer to unsubscribe
+ * all topics the token is subscribed to.
+ */
+// [START remove_stale_tokens]
+exports.pruneTokens = functions.pubsub.schedule('every 24 hours').onRun(async (context) => {
+  // Get all documents where the timestamp exceeds is not within the past month
+  const staleTokensResult = await admin.firestore().collection('fcmTokens')
+      .where("timestamp", "<", Date.now() - EXPIRATION_TIME)
+      .get();
+  // Delete devices with stale tokens
+  staleTokensResult.forEach(function(doc) { doc.ref.delete(); });
+});
+// [END remove_stale_tokens]

messaging/gradle.properties

@@ -15,3 +15,4 @@ org.gradle.jvmargs=-Xmx1536m
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
 # org.gradle.parallel=true
+android.useAndroidX=true