fix(messaging, iOS): refactor notification handling in scene delegate methods (#17905)

* fix(firebase_messaging): enhance iOS scene delegate support and improve notification handling

* fix(firebase_messaging): refactor notification handling in scene delegate methods

* fix(firebase_messaging): improve scene delegate support for notification handling

* chore: remove redundant plugin registration in AppDelegate

Author: SelaseKay

packages/firebase_messaging/firebase_messaging/example/ios/Runner/AppDelegate.h

@@ -1,6 +1,6 @@
 #import <Flutter/Flutter.h>
 #import <UIKit/UIKit.h>
 
-@interface AppDelegate : FlutterAppDelegate
+@interface AppDelegate : FlutterAppDelegate <FlutterImplicitEngineDelegate>
 
 @end

packages/firebase_messaging/firebase_messaging/example/ios/Runner/AppDelegate.m

@@ -5,9 +5,12 @@ @implementation AppDelegate
 
 - (BOOL)application:(UIApplication *)application
     didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
-  [GeneratedPluginRegistrant registerWithRegistry:self];
   // Override point for customization after application launch.
   return [super application:application didFinishLaunchingWithOptions:launchOptions];
 }
 
+- (void)didInitializeImplicitFlutterEngine:(NSObject<FlutterImplicitEngineBridge> *)engineBridge {
+  [GeneratedPluginRegistrant registerWithRegistry:engineBridge.pluginRegistry];
+}
+
 @end

packages/firebase_messaging/firebase_messaging/example/ios/Runner/Info.plist

@@ -50,5 +50,26 @@
 	<true/>
 	<key>UIApplicationSupportsIndirectInputEvents</key>
 	<true/>
+	<key>UIApplicationSceneManifest</key>
+	<dict>
+		<key>UIApplicationSupportsMultipleScenes</key>
+		<false/>
+		<key>UISceneConfigurations</key>
+		<dict>
+			<key>UIWindowSceneSessionRoleApplication</key>
+			<array>
+				<dict>
+					<key>UISceneClassName</key>
+					<string>UIWindowScene</string>
+					<key>UISceneDelegateClassName</key>
+					<string>FlutterSceneDelegate</string>
+					<key>UISceneConfigurationName</key>
+					<string>flutter</string>
+					<key>UISceneStoryboardFile</key>
+					<string>Main</string>
+				</dict>
+			</array>
+		</dict>
+	</dict>
 </dict>
 </plist>

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

@@ -93,6 +93,7 @@ Future<void> setupFlutterNotifications() async {
 }
 
 void showFlutterNotification(RemoteMessage message) {
+  print('foreground message received: ${message.messageId}');
   RemoteNotification? notification = message.notification;
   AndroidNotification? android = message.notification?.android;
   if (notification != null && android != null && !kIsWeb) {
@@ -179,14 +180,17 @@ class _Application extends State<Application> {
   void initState() {
     super.initState();
 
-    FirebaseMessaging.instance.getInitialMessage().then(
-          (value) => setState(
-            () {
-              _resolved = true;
-              initialMessage = value?.data.toString();
-            },
-          ),
-        );
+    // Delay getInitialMessage call by 3 seconds
+    Future.delayed(const Duration(seconds: 3), () {
+      FirebaseMessaging.instance.getInitialMessage().then(
+            (value) => setState(
+              () {
+                _resolved = true;
+                initialMessage = value?.data.toString();
+              },
+            ),
+          );
+    });
 
     FirebaseMessaging.onMessage.listen(showFlutterNotification);
 

packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m

@@ -40,6 +40,9 @@ @implementation FLTFirebaseMessagingPlugin {
   NSString *_notificationOpenedAppID;
   NSString *_foregroundUniqueIdentifier;
 
+  // Track if scene delegate connected (for iOS 13+ scene delegate support)
+  BOOL _sceneDidConnect;
+
 #ifdef __FF_NOTIFICATIONS_SUPPORTED_PLATFORM
   API_AVAILABLE(ios(10), macosx(10.14))
   __weak id<UNUserNotificationCenterDelegate> _originalNotificationCenterDelegate;
@@ -59,6 +62,7 @@ - (instancetype)initWithFlutterMethodChannel:(FlutterMethodChannel *)channel
   self = [super init];
   if (self) {
     _initialNotificationGathered = NO;
+    _sceneDidConnect = NO;
     _channel = channel;
     _registrar = registrar;
     // Application
@@ -216,22 +220,31 @@ - (void)messaging:(nonnull FIRMessaging *)messaging
 
 #pragma mark - NSNotificationCenter Observers
 
-- (void)application_onDidFinishLaunchingNotification:(nonnull NSNotification *)notification {
-  // Setup UIApplicationDelegate.
-#if TARGET_OS_OSX
-  NSDictionary *remoteNotification = notification.userInfo[NSApplicationLaunchUserNotificationKey];
-#else
-  NSDictionary *remoteNotification =
-      notification.userInfo[UIApplicationLaunchOptionsRemoteNotificationKey];
-#endif
+- (void)setupNotificationHandlingWithRemoteNotification:
+    (nullable NSDictionary *)remoteNotification {
   if (remoteNotification != nil) {
     // If remoteNotification exists, it is the notification that opened the app.
     _initialNotification =
         [FLTFirebaseMessagingPlugin remoteMessageUserInfoToDict:remoteNotification];
     _initialNotificationID = remoteNotification[@"gcm.message_id"];
+    _initialNotificationGathered = YES;
+    [self initialNotificationCallback];
+  } else if (_sceneDidConnect) {
+    // For scene delegates, if no notification was found in connectionOptions,
+    // delay marking as gathered to allow didReceiveRemoteNotification to fire first
+    // for contentAvailable notifications that caused the app to launch
+    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)),
+                   dispatch_get_main_queue(), ^{
+                     if (!self->_initialNotificationGathered) {
+                       self->_initialNotificationGathered = YES;
+                       [self initialNotificationCallback];
+                     }
+                   });
+  } else {
+    // For non-scene delegate apps, mark as gathered immediately
+    _initialNotificationGathered = YES;
+    [self initialNotificationCallback];
   }
-  _initialNotificationGathered = YES;
-  [self initialNotificationCallback];
 
   [GULAppDelegateSwizzler registerAppDelegateInterceptor:self];
   [GULAppDelegateSwizzler proxyOriginalDelegateIncludingAPNSMethods];
@@ -314,6 +327,17 @@ - (void)application_onDidFinishLaunchingNotification:(nonnull NSNotification *)n
 #endif
 }
 
+- (void)application_onDidFinishLaunchingNotification:(nonnull NSNotification *)notification {
+  // Setup UIApplicationDelegate.
+#if TARGET_OS_OSX
+  NSDictionary *remoteNotification = notification.userInfo[NSApplicationLaunchUserNotificationKey];
+#else
+  NSDictionary *remoteNotification =
+      notification.userInfo[UIApplicationLaunchOptionsRemoteNotificationKey];
+#endif
+  [self setupNotificationHandlingWithRemoteNotification:remoteNotification];
+}
+
 #pragma mark - UNUserNotificationCenter Delegate Methods
 
 #ifdef __FF_NOTIFICATIONS_SUPPORTED_PLATFORM
@@ -473,6 +497,15 @@ - (BOOL)application:(UIApplication *)application
       [FLTFirebaseMessagingPlugin remoteMessageUserInfoToDict:userInfo];
   // Only handle notifications from FCM.
   if (userInfo[@"gcm.message_id"]) {
+    // For scene delegate apps: if this notification arrives during cold launch
+    // (before initial notification gathering is complete) and no notification was found
+    // in connectionOptions, this is the notification that caused the launch.
+    if (_sceneDidConnect && !_initialNotificationGathered && _initialNotification == nil) {
+      _initialNotification = notificationDict;
+      _initialNotificationID = userInfo[@"gcm.message_id"];
+      _initialNotificationGathered = YES;
+      [self initialNotificationCallback];
+    }
     if ([UIApplication sharedApplication].applicationState == UIApplicationStateBackground) {
       __block BOOL completed = NO;
 
@@ -538,24 +571,21 @@ - (BOOL)application:(UIApplication *)application
 #pragma mark - SceneDelegate Methods
 
 #if !TARGET_OS_OSX
-- (BOOL)scene:(UIScene *)scene
+- (void)scene:(UIScene *)scene
     willConnectToSession:(UISceneSession *)session
                  options:(UISceneConnectionOptions *)connectionOptions {
   // Handle launch notification if present
-  NSDictionary *remoteNotification =
-      connectionOptions.notificationResponse.notification.request.content.userInfo;
-  if (remoteNotification != nil) {
-    // If remoteNotification exists, it is the notification that opened the app.
-    _initialNotification =
-        [FLTFirebaseMessagingPlugin remoteMessageUserInfoToDict:remoteNotification];
-    _initialNotificationID = remoteNotification[@"gcm.message_id"];
+  // With scene delegates, the notification can be in notificationResponse if user tapped it
+  _sceneDidConnect = YES;
+
+  NSDictionary *remoteNotification = nil;
+  if (connectionOptions.notificationResponse != nil) {
+    // User tapped the notification.
+    remoteNotification =
+        connectionOptions.notificationResponse.notification.request.content.userInfo;
   }
 
-  // Register for remote notifications in scene delegate
-  // This is critical for getting APNS token when using UISceneDelegate
-  [[UIApplication sharedApplication] registerForRemoteNotifications];
-
-  return YES;
+  [self setupNotificationHandlingWithRemoteNotification:remoteNotification];
 }
 #endif