3.18. Dart Basics: Push Notifications

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Dart is a programming language developed by Google and used to create mobile, web, and desktop applications. One of Dart's main uses is in developing Flutter apps, a mobile UI framework also developed by Google. In this chapter, we'll explore an important aspect of mobile app development: push notifications and how to implement them in Dart.

Push notifications are messages that mobile apps send to users' devices, even when the app isn't running. They are a powerful marketing tool and an effective way to increase user engagement. However, they can also be used to send important updates, reminders or other relevant information to the user.

To start working with push notifications in Dart, you'll need a library called firebase_messaging. Firebase Messaging is a free service from Google that allows sending push notifications to Android and iOS devices. To add this library to your Flutter project, you will need to add the following line to your pubspec.yaml file:

dependencies:
  firebase_messaging: ^10.0.0

After adding the dependency, you can install the library by running the 'flutter pub get' command in the terminal.

Once the library is installed, you can start implementing push notifications in your application. First, you'll need to import the library into your Dart file:

import 'package:firebase_messaging/firebase_messaging.dart';

Next, you'll need to initialize Firebase Messaging in your app. This is usually done in your application's main() method:

void main() {
  runApp(MyApp());
  FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);
}

The onBackgroundMessage() method is used to handle push notifications that are received when the app is in the background. The _firebaseMessagingBackgroundHandler() method is a function you'll need to define to handle these notifications.

To receive push notifications while the app is in the foreground, you can use the onMessage() method. This method is called whenever a new push notification is received while the app is in foreground:

FirebaseMessaging.onMessage.listen((RemoteMessage message) {
  print('Got a message whilst in the foreground!');
  print('Message data: ${message.data}');

  if (message.notification != null) {
    print('Message also contained a notification: ${message.notification}');
  }
});

Here we are simply printing the notification data and the notification itself, if there is one. However, in practice, you'll likely do something more useful with this information, such as displaying a notification in the status bar or updating the app's UI in some way.

Finally, to request permission to send push notifications to the user, you can use the requestPermission() method. This method displays a prompt to the user, asking for permission to send push notifications:

FirebaseMessaging.instance.requestPermission(
  alert: true,
  badge: true,
  sound: true,
);

In short, push notifications are an important part of mobile app development and Dart makes it relatively easy to implement them in your Flutter apps. With the firebase_messaging library, you can send push notifications to Android and iOS devices, receive push notifications while your app is in foreground or background, and request permission to send push notifications. With these tools in hand, you are well equipped to create engaging and interactive mobile apps with Flutter and Dart.

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373.19. Dart Basics: Publishing Applications