Sometimes user wants some very important features like the latest news updates, latest articles updates, weather condition alert, complete his/her profile update, future events update and much more in his/ her Android or iOS device without opening App and if you would like to develop this kind of Android and iOS application then this article will help you to do so. In this process, we set up background jobs that periodically check updates about the latest events or alerts.
Flutter Local Notifications:
It is a cross-platform plugin for displaying local notifications in a flutter application. It offers a bunch of features like for example scheduling when notifications should appear, periodically showing a notification (interval-based), handling when a user has tapped on a notification when the app is in the foreground, background, or terminated, specifying a custom notification sound and much more.
open the ‘pubspec.yaml’ file and copy-paste two dependencies that are Workmanager and flutter_local_notifications as follows.
dependencies:
flutter:
sdk: flutter
# Use with the Workmanger class for background jobs headless execution.
workmanager: ^0.2.3
# Use with FlutterLocalNotificationsPlugin class for local push notifications.
flutter_local_notifications: ^1.4.4+2
Once, you have done the above steps then click on ‘Packages get’ flutter command appearing at the center top to get install all necessary packages and plugins.
Now, It’s time to add some required permissions, open the ‘AndroidManifest.xml’ file from android -> app -> src -> main -> AndroidManifest.xml project directory structure and copy-paste the following permissions.
<!-- Add below permission inside 'manifest' tag -->
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
<!-- Add below permission inside 'application' tag -->
<receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED"/>
<action android:name="android.intent.action.MY_PACKAGE_REPLACED"/>
</intent-filter>
</receiver>
open ‘main.dart’ file from lib -> main.dart project directory structure and copy-paste following the entire code.
import 'package:flutter/material.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:workmanager/workmanager.dart';
void main() {
// needed if you intend to initialize in the `main` function
WidgetsFlutterBinding.ensureInitialized();
Workmanager().initialize(
// The top level function, aka callbackDispatcher
callbackDispatcher,
// If enabled it will post a notification whenever
// the task is running. Handy for debugging tasks
isInDebugMode: true
);
// Periodic task registration
Workmanager().registerPeriodicTask(
"2",
//This is the value that will be
// returned in the callbackDispatcher
"simplePeriodicTask",
// When no frequency is provided
// the default 15 minutes is set.
// Minimum frequency is 15 min.
// Android will automatically change
// your frequency to 15 min
// if you have configured a lower frequency.
frequency: Duration(minutes: 15),
);
runApp(MyApp());
}
void callbackDispatcher() {
Workmanager().executeTask((task, inputData) {
// initialise the plugin of flutterlocalnotifications.
FlutterLocalNotificationsPlugin flip = new FlutterLocalNotificationsPlugin();
// app_icon needs to be a added as a drawable
// resource to the Android head project.
var android = new AndroidInitializationSettings('@mipmap/ic_launcher');
var IOS = new IOSInitializationSettings();
// initialise settings for both Android and iOS device.
var settings = new InitializationSettings(android, IOS);
flip.initialize(settings);
_showNotificationWithDefaultSound(flip);
return Future.value(true);
});
}
Future _showNotificationWithDefaultSound(flip) async {
// Show a notification after every 15 minute with the first
// appearance happening a minute after invoking the method
var androidPlatformChannelSpecifics = new AndroidNotificationDetails(
'your channel id',
'your channel name',
'your channel description',
importance: Importance.Max,
priority: Priority.High
);
var iOSPlatformChannelSpecifics = new IOSNotificationDetails();
// initialise channel platform for both Android and iOS device.
var platformChannelSpecifics = new NotificationDetails(
androidPlatformChannelSpecifics,
iOSPlatformChannelSpecifics
);
await flip.show(0, 'GeeksforGeeks',
'Your are one step away to connect with GeeksforGeeks',
platformChannelSpecifics, payload: 'Default_Sound'
);
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Geeks Demo',
theme: ThemeData(
// This is the theme
// of your application.
primarySwatch: Colors.green,
),
home: HomePage(title: "GeeksforGeeks"),
);
}
}
class HomePage extends StatefulWidget {
HomePage({Key key, this.title}) : super(key: key);
// This widget is the home page of your application.
// It is stateful, meaning
// that it has a State object (defined below)
// that contains fields that affect
// how it looks.
// This class is the configuration for the state.
// It holds the values (in this
// case the title) provided by the parent
// (in this case the App widget) and
// used by the build method of the State.
// Fields in a Widget subclass are
// always marked "final".
final String title;
@override
_HomePageState createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> {
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called.
// The Flutter framework has been optimized
// to make rerunning build methods
// fast, so that you can just rebuild
// anything that needs updating rather
// than having to individually change
//instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from
// the MyHomePage object that was created by
// the App.build method, and use it
// to set our appbar title.
title: Text(widget.title),
),
body: new Container(),
);
}
}