In this tutorial, we will learn how to implement Firebase Push Notification with Flutter apps
What you’ll learn?
A Flutter plugin to use the Firebase Cloud Messaging (FCM) API.
With this plugin, your Flutter app can receive and process push notifications as well as data messages on Android and iOS. Read Firebase’s About FCM Messages to learn more about the differences between notification messages and data messages.
1. Depend on it
Add this to your package’s pubspec.yaml
file:
dependencies:
firebase_messaging: ^5.1.8
2. Install it
You can install packages from the command line:
with Flutter:
flutter pub get
Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.
3. Import it
Now in your Dart code, you can use:
import 'package:firebase_messaging/firebase_messaging.dart';
Check out the example
directory for a sample app using Firebase Cloud Messaging.
To integrate your plugin into the Android part of your app, follow these steps:
Using the Firebase Console add an Android app to your project: Follow the assistant, download the generated google-services.json
file and place it inside android/app
.
Add the classpath to the [project]/android/build.gradle
file.
dependencies {
// Example existing classpath
classpath 'com.android.tools.build:gradle:3.2.1'
// Add the google services classpath
classpath 'com.google.gms:google-services:4.3.0'
}
Add the apply plugin to the [project]/android/app/build.gradle
file.
// ADD THIS AT THE BOTTOM
apply plugin: 'com.google.gms.google-services'
Note: If this section is not completed you will get an error like this:
java.lang.IllegalStateException:
Default FirebaseApp is not initialized in this process [package name].
Make sure to call FirebaseApp.initializeApp(Context) first.
Note: When you are debugging on Android, use a device or AVD with Google Play services. Otherwise you will not be able to authenticate.
onResume
and onLaunch
, see below) when the user clicks on a notification in the system tray include the following intent-filter
within the <activity>
tag of your android/app/src/main/AndroidManifest.xml
: intent-filter>
action android:name="FLUTTER_NOTIFICATION_CLICK" />
category android:name="android.intent.category.DEFAULT" />
intent-filter>
Background message handling is intended to be performed quickly. Do not perform long running tasks as they may not be allowed to finish by the Android system. See Background Execution Limits for more.
By default background messaging is not enabled. To handle messages in the background:
1. Add an Application.java class to your app
package io.flutter.plugins.firebasemessagingexample;
import io.flutter.app.FlutterApplication;
import io.flutter.plugin.common.PluginRegistry;
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback;
import io.flutter.plugins.GeneratedPluginRegistrant;
import io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService;
public class Application extends FlutterApplication implements PluginRegistrantCallback {
@Override
public void onCreate() {
super.onCreate();
FlutterFirebaseMessagingService.setPluginRegistrant(this);
}
@Override
public void registerWith(PluginRegistry registry) {
GeneratedPluginRegistrant.registerWith(registry);
}
}
2. Set name property of application in AndroidManifest.xml
<application android:name=".Application" ...>
3. Define a top level Dart method to handle background messages
Future<dynamic> myBackgroundMessageHandler(Map<String, dynamic> message) {
if (message.containsKey('data')) {
// Handle data message
final dynamic data = message['data'];
}
if (message.containsKey('notification')) {
// Handle notification message
final dynamic notification = message['notification'];
}
// Or do other work.
}
Note: the protocol of data
and notification
are in line with the fields defined by a RemoteMessage.
onBackgroundMessage
handler when calling configure
_firebaseMessaging.configure(
onMessage: (Map<String, dynamic> message) async {
print("onMessage: $message");
_showItemDialog(message);
},
onBackgroundMessage: myBackgroundMessageHandler,
onLaunch: (Map<String, dynamic> message) async {
print("onLaunch: $message");
_navigateToItemDetail(message);
},
onResume: (Map<String, dynamic> message) async {
print("onResume: $message");
_navigateToItemDetail(message);
},
);
Note: configure
should be called early in the lifecycle of your application so that it can be ready to receive messages as early as possible. See the example app for a demonstration.
To integrate your plugin into the iOS part of your app, follow these steps:
1.Generate the certificates required by Apple for receiving push notifications following this guide in the Firebase docs. You can skip the section titled “Create the Provisioning Profile”.
GoogleService-Info.plist
file, open ios/Runner.xcworkspace
with Xcode, and within Xcode place the file inside ios/Runner
. Don’t follow the steps named “Add Firebase SDK” and “Add initialization code” in the Firebase assistant.Runner
in the Project Navigator. In the Capabilities Tab turn on Push Notifications
and Background Modes
, and enable Background fetch
and Remote notifications
under Background Modes
.From your Dart code, you need to import the plugin and instantiate it:
import 'package:firebase_messaging/firebase_messaging.dart';
final FirebaseMessaging _firebaseMessaging = FirebaseMessaging();
Next, you should probably request permissions for receiving Push Notifications. For this, call _firebaseMessaging.requestNotificationPermissions()
. This will bring up a permissions dialog for the user to confirm on iOS. It’s a no-op on Android. Last, but not least, register onMessage
, onResume
, and onLaunch
callbacks via _firebaseMessaging.configure()
to listen for incoming messages (see table below for more information).
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:
App in ForegroundApp in BackgroundApp TerminatedNotification on AndroidonMessage
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 iOSonMessage
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.Data Message on AndroidonMessage``````onMessage
while app stays in the background.not supported by plugin, message is lostData Message on iOSonMessage
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.
Additional reading: Firebase’s About FCM Messages.
It is possible to include additional data in notification messages by adding them to the "data"
-field of the message.
On Android, the message contains an additional field data
containing the data. On iOS, the data is directly appended to the message and the additional data
-field is omitted.
To receive the data on both platforms:
Futurevoid> _handleNotification (Mapdynamic, dynamic> message, bool dialog) async {
var data = message['data'] ?? message;
String expectedAttribute = data['expectedAttribute'];
/// [...]
}
Refer to the Firebase documentation about FCM for all the details about sending messages to your app. When sending a notification message to an Android device, you need to make sure to set the click_action
property of the message to FLUTTER_NOTIFICATION_CLICK
. Otherwise the plugin will be unable to deliver the notification to your app when the users clicks on it in the system tray.
For testing purposes, the simplest way to send a notification is via the Firebase Console. Make sure to include click_action: FLUTTER_NOTIFICATION_CLICK
as a “Custom data” key-value-pair (under “Advanced options”) when targeting an Android device. The Firebase Console does not support sending data messages.
Alternatively, a notification or data message can be sent from a terminal:
DATA='{"notification": {"body": "this is a body","title": "this is a title"}, "priority": "high", "data": {"click_action": "FLUTTER_NOTIFICATION_CLICK", "id": "1", "status": "done"}, "to": "<FCM TOKEN>"}'
curl https://fcm.googleapis.com/fcm/send -H "Content-Type:application/json" -X POST -d "$DATA" -H "Authorization: key=<FCM SERVER KEY>"
Remove the notification
property in DATA
to send a data message.
#flutter #firebase