Flutter: Local Notification Scheduling

Question

I am trying to set a scheduled alarm notification from the user selected date and time which i used showDatePicker for code below

DateTime _selectedDateAndTime;

  Future _selectDayAndTimeL(BuildContext context) async {
    DateTime _selectedDay = await showDatePicker(
        context: context,
        initialDate: DateTime.now(),
        firstDate: DateTime(2021),
        lastDate: DateTime(2030),
        builder: (BuildContext context, Widget child) => child);

    TimeOfDay _selectedTime = await showTimePicker(
      context: context,
      initialTime: TimeOfDay.now(),
    );

    if (_selectedDay != null && _selectedTime != null) {
      //a little check
    }
    setState(() {
      _selectedDateAndTime = DateTime(
        _selectedDay.year,
        _selectedDay.month,
        _selectedDay.day,
        _selectedTime.hour,
        _selectedTime.minute,
      );
      // _selectedDate = _selectedDay;
    });
    // print('...');
  }

which after the date and time has been selected the value is formatted like in the picture bellow

Now i want to be able to set the Scheduled Notification using the value from the selection but not sure how to do it... i have installed Flutter_Local_Notification and have imported it to my main.dart, have set the permission in the manifest file and have also tried to initial the plugin like down bellow

FlutterLocalNotificationsPlugin fltrNotification;
  String _selectedParam;
  int val;

  @override
  void initState() {
    super.initState();
    var androidInitilize = new AndroidInitializationSettings('app_icon');
    var iOSinitilize = new IOSInitializationSettings();
    var initilizationsSettings =
        new InitializationSettings(androidInitilize, iOSinitilize);
    fltrNotification = new FlutterLocalNotificationsPlugin();
    fltrNotification.initialize(initilizationsSettings,
        onSelectNotification: notificationSelected);
  }

and i have also added the app_icon.png to my drawable folder

i have tried to follow some tutorial on how to do it but most of them only show how to set the netification using seconds but for my own project i want to set the schedule for a particular day, hour and minute

please how can i achive that?

Answer 1

You can use this my helper class

class NotificationPlugin {
  FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin;

  var initializationSettings;

  NotificationPlugin._() {
    init();
  }

  init() async {
    flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();
    if (Platform.isIOS) {
      _requestIOSPermission();
    }
    initializePlatformSpecifics();
  }

  initializePlatformSpecifics() {
    var initializationSettingsAndroid = AndroidInitializationSettings(
        'mipmap/ic_launcher'); // <- default icon name is @mipmap/ic_launcher
    var initializationSettingsIOS =
        IOSInitializationSettings(onDidReceiveLocalNotification: (int a, String b, String c, d) {});
    var initializationSettings =
        InitializationSettings(initializationSettingsAndroid, initializationSettingsIOS);
    flutterLocalNotificationsPlugin.initialize(initializationSettings,
        onSelectNotification: (String s) {});

    initializationSettings =
        InitializationSettings(initializationSettingsAndroid, initializationSettingsIOS);
  }

  _requestIOSPermission() {
    flutterLocalNotificationsPlugin
        .resolvePlatformSpecificImplementation<IOSFlutterLocalNotificationsPlugin>()
        .requestPermissions(alert: false, badge: true, sound: true);
  }

  setOnNotificationClick(Function onNotificationClick) async {
    await flutterLocalNotificationsPlugin.initialize(
      initializationSettings,
      onSelectNotification: (payload) async {
        onNotificationClick(payload);
      },
    );
  }

  Future<void> showNotification(
      {@required int id, @required String title, @required String body}) async {
    var androidChannelSpecifics = AndroidNotificationDetails(
      'CHANNEL_ID',
      'CHANNEL_NAME',
      'CHANNEL_DESCRIPTION',
      importance: Importance.High,
      priority: Priority.High,
    );
    var iosChannelSpecifics = IOSNotificationDetails();
    var platformChannelSpecifics = NotificationDetails(
      androidChannelSpecifics,
      iosChannelSpecifics,
    );
    await flutterLocalNotificationsPlugin.show(id, title, body, platformChannelSpecifics,
        payload: id.toString());
  }

  Future<void> showScheduledNotification(
      {@required int id,
      @required String title,
      @required String body,
      @required String date}) async {
    var scheduledNotificationDateTime = DateTime.parse(date);

    var androidPlatformChannelSpecifics = AndroidNotificationDetails(
        'your other channel id', 'your other channel name', 'your other channel description');
    var iOSPlatformChannelSpecifics = IOSNotificationDetails();
    NotificationDetails platformChannelSpecifics =
        NotificationDetails(androidPlatformChannelSpecifics, iOSPlatformChannelSpecifics);
    await flutterLocalNotificationsPlugin.schedule(
        id, '$title', '  $body', scheduledNotificationDateTime, platformChannelSpecifics,
        androidAllowWhileIdle: true);
  }

  Future<void> removeNotifications() async {
    await flutterLocalNotificationsPlugin.cancelAll();
  }
}

NotificationPlugin notificationPlugin = NotificationPlugin._();

and then you can call

await notificationPlugin.showScheduledNotification(
                id: 123,
                title:"fancy title",
                body: "data",
                date: yourDate,
              );

///////////////////////////////// if you will not use the helper class this is simply what you need

var scheduledNotificationDateTime = DateTime.parse(date); // replace whith your date

var androidPlatformChannelSpecifics = AndroidNotificationDetails(
    'your other channel id', 'your other channel name', 'your other channel description');
var iOSPlatformChannelSpecifics = IOSNotificationDetails();
NotificationDetails platformChannelSpecifics =
    NotificationDetails(androidPlatformChannelSpecifics, iOSPlatformChannelSpecifics);
await flutterLocalNotificationsPlugin.schedule(
    id, '$title', '  $body', scheduledNotificationDateTime, platformChannelSpecifics,
    androidAllowWhileIdle: true);