[firebase_messaging] Separate onLaunch to an specific method to be able to retrieve launch message in a synchronous way

Author: jherencia

packages/firebase_messaging/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 6.0.8
+* Separated onLaunch to an specific method to be able to retrieve launch
+  message in a synchronous way.
+* Deprecated the `onLaunch` function from `FirebaseMessaging.configure`.
+
 ## 6.0.7
 
 * Remove the deprecated `author:` field from pubspec.yaml

packages/firebase_messaging/README.md

@@ -176,12 +176,18 @@ Next, you should probably request permissions for receiving Push Notifications.
 
 ## Receiving Messages
 
-Messages are sent to your Flutter app via the `onMessage`, `onLaunch`, and `onResume` callbacks that you configured with the plugin during setup. Here is how different message types are delivered on the supported platforms:
+Launch messages (when application is closed) are retrieved on application init so you can act based on the notification data:
+
+```dart
+ Map<String, dynamic> message = await _firebaseMessaging.getLaunchMessage();
+```
+
+Messages when the application is not in foreground are sent to your Flutter app via the `onMessage` and `onResume` callbacks that you configured with the plugin during setup. Here is how different message types are delivered on the supported platforms:
 
 |                             | App in Foreground | App in Background | App Terminated |
 | --------------------------: | ----------------- | ----------------- | -------------- |
-| **Notification on Android** | `onMessage` | Notification is delivered to system tray. When the user clicks on it to open app `onResume` fires if `click_action: FLUTTER_NOTIFICATION_CLICK` is set (see below). | Notification is delivered to system tray. When the user clicks on it to open app `onLaunch` fires if `click_action: FLUTTER_NOTIFICATION_CLICK` is set (see below). |
-| **Notification on iOS** | `onMessage` | Notification is delivered to system tray. When the user clicks on it to open app `onResume` fires. | Notification is delivered to system tray. When the user clicks on it to open app `onLaunch` fires. |
+| **Notification on Android** | `onMessage` | Notification is delivered to system tray. When the user clicks on it to open app `onResume` fires if `click_action: FLUTTER_NOTIFICATION_CLICK` is set (see below). | Notification is delivered to system tray. When the user clicks on it to open app `getLaunchMessage` fires if `click_action: FLUTTER_NOTIFICATION_CLICK` is set (see below). |
+| **Notification on iOS** | `onMessage` | Notification is delivered to system tray. When the user clicks on it to open app `onResume` fires. | Notification is delivered to system tray. When the user clicks on it to open app `getLaunchMessage` fires. |
 | **Data Message on Android** | `onMessage` | `onMessage` while app stays in the background. | *not supported by plugin, message is lost* |
 | **Data Message on iOS**     | `onMessage` | Message is stored by FCM and delivered to app via `onMessage` when the app is brought back to foreground. | Message is stored by FCM and delivered to app via `onMessage` when the app is brought back to foreground. |
 

packages/firebase_messaging/android/src/main/java/io/flutter/plugins/firebasemessaging/FirebaseMessagingPlugin.java

@@ -199,6 +199,13 @@ public void onComplete(@NonNull Task<InstanceIdResult> task) {
         sendMessageFromIntent("onLaunch", mainActivity.getIntent());
       }
       result.success(null);
+    } else if ("getLaunchMessage".equals(call.method)) {
+      if (mainActivity != null) {
+        Map<String, Object> message = this.getMessageFromIntent(mainActivity.getIntent());
+        result.success(message);
+        return;
+      }
+      result.success(null);
     } else if ("subscribeToTopic".equals(call.method)) {
       String topic = call.arguments();
       FirebaseMessaging.getInstance()
@@ -300,15 +307,14 @@ public boolean onNewIntent(Intent intent) {
     return res;
   }
 
-  /** @return true if intent contained a message to send. */
-  private boolean sendMessageFromIntent(String method, Intent intent) {
+  private Map<String, Object> getMessageFromIntent(Intent intent) {
     if (CLICK_ACTION_VALUE.equals(intent.getAction())
         || CLICK_ACTION_VALUE.equals(intent.getStringExtra("click_action"))) {
       Map<String, Object> message = new HashMap<>();
       Bundle extras = intent.getExtras();
 
       if (extras == null) {
-        return false;
+        return null;
       }
 
       Map<String, Object> notificationMap = new HashMap<>();
@@ -323,10 +329,20 @@ private boolean sendMessageFromIntent(String method, Intent intent) {
 
       message.put("notification", notificationMap);
       message.put("data", dataMap);
+      return message;
+    }
+    return null;
+  }
 
-      channel.invokeMethod(method, message);
-      return true;
+  /** @return true if intent contained a message to send. */
+  private boolean sendMessageFromIntent(String method, Intent intent) {
+    Map<String, Object> message = this.getMessageFromIntent(intent);
+
+    if (message == null) {
+      return false;
     }
-    return false;
+
+    channel.invokeMethod(method, message);
+    return true;
   }
 }

packages/firebase_messaging/example/lib/main.dart

@@ -138,15 +138,23 @@ class _PushMessagingExampleState extends State<PushMessagingExample> {
   @override
   void initState() {
     super.initState();
+    initPushNotifications();
+  }
+
+  void initPushNotifications() async {
+    final Map<String, dynamic> message =
+        await _firebaseMessaging.getLaunchMessage();
+
+    if (message != null) {
+      print("getLaunchMessage $message");
+      _navigateToItemDetail(message);
+    }
+
     _firebaseMessaging.configure(
       onMessage: (Map<String, dynamic> message) async {
         print("onMessage: $message");
         _showItemDialog(message);
       },
-      onLaunch: (Map<String, dynamic> message) async {
-        print("onLaunch: $message");
-        _navigateToItemDetail(message);
-      },
       onResume: (Map<String, dynamic> message) async {
         print("onResume: $message");
         _navigateToItemDetail(message);

packages/firebase_messaging/ios/Classes/FLTFirebaseMessagingPlugin.m

@@ -124,6 +124,8 @@ - (void)handleMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result
       [[UIApplication sharedApplication] registerForRemoteNotifications];
       result([NSNumber numberWithBool:YES]);
     }
+  } else if ([@"getLaunchMessage" isEqualToString:method]) {
+    result(_launchNotification);
   } else if ([@"configure" isEqualToString:method]) {
     [FIRMessaging messaging].shouldEstablishDirectChannel = true;
     [[UIApplication sharedApplication] registerForRemoteNotifications];

packages/firebase_messaging/lib/firebase_messaging.dart

@@ -104,7 +104,8 @@ class FirebaseMessaging {
   void configure({
     MessageHandler onMessage,
     MessageHandler onBackgroundMessage,
-    MessageHandler onLaunch,
+    @Deprecated('Use `FirebaseMessaging.getLaunchMessage` instead.')
+        MessageHandler onLaunch,
     MessageHandler onResume,
   }) {
     _onMessage = onMessage;
@@ -137,6 +138,13 @@ class FirebaseMessaging {
     }
   }
 
+  /// Retrieves the FCM message that launched the application (if any,
+  /// otherwise returns null).
+  Future<Map<dynamic, dynamic>> getLaunchMessage() async {
+    return await _channel
+        .invokeMethod<Map<dynamic, dynamic>>('getLaunchMessage');
+  }
+
   final StreamController<String> _tokenStreamController =
       StreamController<String>.broadcast();
 

packages/firebase_messaging/pubspec.yaml

@@ -2,7 +2,7 @@ name: firebase_messaging
 description: Flutter plugin for Firebase Cloud Messaging, a cross-platform
   messaging solution that lets you reliably deliver messages on Android and iOS.
 homepage: https://github.com/FirebaseExtended/flutterfire/tree/master/packages/firebase_messaging
-version: 6.0.7
+version: 6.0.8
 
 flutter:
   plugin:

packages/firebase_messaging/test/firebase_messaging_test.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// ignore_for_file: deprecated_member_use_from_same_package
+
 import 'dart:async';
 
 import 'package:flutter/services.dart';
@@ -92,6 +94,42 @@ void main() {
     expect((await iosSettingsFromStream).toMap(), iosSettings.toMap());
   });
 
+  test('getLaunchMessage', () async {
+    final MethodChannel channel =
+        const MethodChannel('plugins.flutter.io/firebase_messaging');
+    firebaseMessaging =
+        FirebaseMessaging.private(channel, const LocalPlatform());
+
+    channel.setMockMethodCallHandler((MethodCall methodCall) async {
+      switch (methodCall.method) {
+        case 'getLaunchMessage':
+          return <dynamic, dynamic>{
+            'notification': <dynamic, dynamic>{
+              'title': 'Title',
+              'body': 'Body',
+              'click_action': 'FLUTTER_NOTIFICATION_CLICK',
+            },
+            'data': <dynamic, dynamic>{
+              'variable1': 'value1',
+              'variable2': 'value2',
+            },
+          };
+        default:
+          return null;
+      }
+    });
+
+    final Map<dynamic, dynamic> message =
+        await firebaseMessaging.getLaunchMessage();
+
+    expect(message['notification']['title'], 'Title');
+    expect(message['notification']['body'], 'Body');
+    expect(
+        message['notification']['click_action'], 'FLUTTER_NOTIFICATION_CLICK');
+    expect(message['data']['variable1'], 'value1');
+    expect(message['data']['variable2'], 'value2');
+  });
+
   test('incoming messages', () async {
     final Completer<dynamic> onMessage = Completer<dynamic>();
     final Completer<dynamic> onLaunch = Completer<dynamic>();