How to add Scheduled notification in flutter - flutter

Question

I have been trying to add a scheduled notification feature to my todo app but am unable to do so, when the notification is supposed to appear, it does not and the app crashes, I want the notification to be added when the add button in the todoScreen is clicked.
any help would be really appreciated.
todoScreen link: https://github.com/Rohith-JN/Reminders_App/blob/main/lib/Screens/TodoScreen.dart
notification link: https://github.com/Rohith-JN/Reminders_App/blob/main/lib/notification_service.dart

Answer 1

Okay pushing notification with flutter is pretty easy.
Add these dependencies to pubspec.yaml:
dependencies:
flutter_local_notifications: ^1.4.2
rxdart: ^0.23.1
Particular plugins: flutter_local_notifications and rxdart
then run this command in the terminal:
flutter pub get
Go to AndroidManifest.xml in /android/app/src/main/ and add these lines:
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
Now, go to AppDelegate.swift in /ios/Runner/ Add:
if #available(iOS 10.0, *) {
UNUserNotificationCenter.current().delegate = self as ?
UNUserNotificationCenterDelegate
}
before these lines:
return super.application(application, didFinishLaunchingWithOptions: launchOptions)
Done?
Now, Create a notifications_helper.dart file and import the flutter_local_notifications and rxdart packages.
Then in that file add these:
class NotificationClass{
final int id;
final String title;
final String body;
final String payload;
NotificationClass({this.id, this.body, this.payload, this.title});
}
Also add these finals:
final rxSub.BehaviorSubject<NotificationClass> didReceiveLocalNotificationSubject =
rxSub.BehaviorSubject<NotificationClass>();
final rxSub.BehaviorSubject<String> selectNotificationSubject =
rxSub.BehaviorSubject<String>();
Now finally add the following method to helper file:
Future<void> initNotifications(
notifs.FlutterLocalNotificationsPlugin
notifsPlugin) async {
var initializationSettingsAndroid =
notifs.AndroidInitializationSettings('icon');
var initializationSettingsIOS = notifs.IOSInitializationSettings(
requestAlertPermission: false,
requestBadgePermission: false,
requestSoundPermission: false,
onDidReceiveLocalNotification:
(int id, String title, String body, String payload) async {
didReceiveLocalNotificationSubject
.add(NotificationClass(id: id, title: title, body: body, payload: payload));
});
var initializationSettings = notifs.InitializationSettings(
initializationSettingsAndroid, initializationSettingsIOS);
await notifsPlugin.initialize(initializationSettings,
onSelectNotification: (String payload) async {
if (payload != null) {
print('notification payload: ' + payload);
}
selectNotificationSubject.add(payload);
});
print("Notifications initialised successfully");
}
For permission request method for iOS:
void requestIOSPermissions(
notifs.FlutterLocalNotificationsPlugin notifsPlugin) {
notifsPlugin.resolvePlatformSpecificImplementation<notifs.IOSFlutterLocalNotificationsPlugin>()
?.requestPermissions(
alert: true,
badge: true,
sound: true,
);
}
Done Up To This?
Now, scheduled notification, add these:
Future<void> scheduleNotification(
{notifs.FlutterLocalNotificationsPlugin notifsPlugin,
String id,
String title,
String body,
DateTime scheduledTime}) async {
var androidSpecifics = notifs.AndroidNotificationDetails(
id, // This specifies the ID of the Notification
'Scheduled notification', // This specifies the name of the notification channel
'A scheduled notification', //This specifies the description of the channel
icon: 'icon',
);
var iOSSpecifics = notifs.IOSNotificationDetails();
var platformChannelSpecifics = notifs.NotificationDetails(
androidSpecifics, iOSSpecifics);
await notifsPlugin.schedule(0, title, "Scheduled notification",
scheduledTime, platformChannelSpecifics); // This literally schedules the notification
}
Now modify the main.dart file:
NotificationAppLaunchDetails notifLaunch;
final FlutterLocalNotificationsPlugin notifsPlugin=
FlutterLocalNotificationsPlugin();
Now within the main method, add
notifLaunch = await notifsPlugin.getNotificationAppLaunchDetails();
await initNotifications(notifsPlugin);
requestIOSPermissions(notifsPlugin);
NOW MAIN THING,
Triggering a scheduled Notification, Import your helper file and main.dart:
import '../helpers/notifications_helper.dart';
import '../main.dart';
Now call the scheduleNotification method:
scheduleNotification(
notifsPlugin: notifsPlugin, //Or whatever you've named it in main.dart
id: DateTime.now().toString(),
body: "A scheduled Notification",
scheduledTime: DateTime.now()); //Or whenever you actually want to trigger it
And My friend you are done!👍