fix(firebase_messaging, iOS): ensure initial notification was tapped to open app. fixes getInitialMessage() & onMessageOpenedApp() . (#9315)

Co-authored-by: Mike Diarmid <mike.diarmid@gmail.com>

Author: russellwheatley

packages/firebase_messaging/firebase_messaging/example/lib/main.dart

@@ -174,17 +174,6 @@ class _Application extends State<Application> {
   @override
   void initState() {
     super.initState();
-    FirebaseMessaging.instance
-        .getInitialMessage()
-        .then((RemoteMessage? message) {
-      if (message != null) {
-        Navigator.pushNamed(
-          context,
-          '/message',
-          arguments: MessageArguments(message, true),
-        );
-      }
-    });
 
     FirebaseMessaging.onMessage.listen(showFlutterNotification);
 
@@ -308,6 +297,22 @@ class _Application extends State<Application> {
                     : Text(token, style: const TextStyle(fontSize: 12));
               }),
             ),
+            ElevatedButton(
+              onPressed: () {
+                FirebaseMessaging.instance
+                    .getInitialMessage()
+                    .then((RemoteMessage? message) {
+                  if (message != null) {
+                    Navigator.pushNamed(
+                      context,
+                      '/message',
+                      arguments: MessageArguments(message, true),
+                    );
+                  }
+                });
+              },
+              child: const Text('getInitialMessage()'),
+            ),
             MetaCard('Message Stream', MessageList()),
           ],
         ),

packages/firebase_messaging/firebase_messaging/ios/Classes/FLTFirebaseMessagingPlugin.m

@@ -22,6 +22,8 @@ @implementation FLTFirebaseMessagingPlugin {
   NSObject<FlutterPluginRegistrar> *_registrar;
   NSData *_apnsToken;
   NSDictionary *_initialNotification;
+  NSString *_initialNoticationID;
+  NSString *_notificationOpenedAppID;
 
 #ifdef __FF_NOTIFICATIONS_SUPPORTED_PLATFORM
   API_AVAILABLE(ios(10), macosx(10.14))
@@ -43,7 +45,6 @@ - (instancetype)initWithFlutterMethodChannel:(FlutterMethodChannel *)channel
   if (self) {
     _channel = channel;
     _registrar = registrar;
-
     // Application
     // Dart -> `getInitialNotification`
     // ObjC -> Initialize other delegates & observers
@@ -204,6 +205,7 @@ - (void)application_onDidFinishLaunchingNotification:(nonnull NSNotification *)n
     // If remoteNotification exists, it is the notification that opened the app.
     _initialNotification =
         [FLTFirebaseMessagingPlugin remoteMessageUserInfoToDict:remoteNotification];
+    _initialNoticationID = remoteNotification[@"gcm.message_id"];
   }
 
 #if TARGET_OS_OSX
@@ -334,8 +336,11 @@ - (void)userNotificationCenter:(UNUserNotificationCenter *)center
              withCompletionHandler:(void (^)(void))completionHandler
     API_AVAILABLE(macos(10.14), ios(10.0)) {
   NSDictionary *remoteNotification = response.notification.request.content.userInfo;
-  // We only want to handle FCM notifications.
-  if (remoteNotification[@"gcm.message_id"]) {
+  _notificationOpenedAppID = remoteNotification[@"gcm.message_id"];
+  // We only want to handle FCM notifications and stop firing `onMessageOpenedApp()` when app is
+  // coming from a terminated state.
+  if (_notificationOpenedAppID != nil &&
+      ![_initialNoticationID isEqualToString:_notificationOpenedAppID]) {
     NSDictionary *notificationDict =
         [FLTFirebaseMessagingPlugin remoteMessageUserInfoToDict:remoteNotification];
     [_channel invokeMethod:@"Messaging#onMessageOpenedApp" arguments:notificationDict];
@@ -995,7 +1000,10 @@ - (void)ensureAPNSTokenSetting {
 
 - (nullable NSDictionary *)copyInitialNotification {
   @synchronized(self) {
-    if (_initialNotification != nil) {
+    // Only return if initial notification was sent when app is terminated. Also ensure that
+    // it was the initial notification that was tapped to open the app.
+    if (_initialNotification != nil &&
+        [_initialNoticationID isEqualToString:_notificationOpenedAppID]) {
       NSDictionary *initialNotificationCopy = [_initialNotification copy];
       _initialNotification = nil;
       return initialNotificationCopy;