Is it possible to pass parameter on onSelectNotification for flutter_local_notification plugin

Question

Sorry, I am new to flutter and currently facing difficulties when implementing notification for my app. I am using flutter_local_notification plugin, as I heard it is useful for reminder purpose, as well as using it for an offline app.

I'm currently facing a problem of passing my Note (model) object to my onSelectNotification function

My Objective: create a reminder icon for my Note app, such that when the notification is triggered by the flutter_local_notification plugin. Tapping the notification will allow me to proceed to my EditNotePage activity, with the corresponding Note object parameters (title, description) appears on it

How can I modify the onSelectNotification such that I can pass my Note object to it.

All help is deeply appreciated!

Sorry for not providing much code.

FlutterLocalNotificationsPlugin 
flutterLocalNotificationsPlugin = 
new FlutterLocalNotificationsPlugin();

var initializationSettingsAndroid =
new AndroidInitializationSettings('app_icon');
var initializationSettingsIOS = IOSInitializationSettings(
onDidReceiveLocalNotification: onDidReceiveLocalNotification);
var initializationSettings = InitializationSettings(
initializationSettingsAndroid, initializationSettingsIOS);


flutterLocalNotificationsPlugin.initialize(initializationSettings,
onSelectNotification: onSelectNotification);

Solution

You can encode your Note object to a JSON string and pass that into the method to set your reminder like below:

Say this is your Note class:

    import 'package:meta/meta.dart';
    import 'dart:convert';

    class Note {
        final String title;    
        final String description;

        Note({@required this.title, @required this.description});

        //Add these methods below

        factory Note.fromJsonString(String str) => Note._fromJson(jsonDecode(str));

        String toJsonString() => jsonEncode(_toJson());

        factory Note._fromJson(Map<String, dynamic> json) => Note(
           title: json['title'],
           description: json['description'],
        );


        Map<String, dynamic> _toJson() => {
            'title': title,
            'description': description,
        };
    }

Now, to set your notification, you can create the JSON string from your model and pass it as the payload to the flutterLocalNotificationsPlugin method like below:

    Note newNote = Note(title : 'Hello', description : 'This is my first reminder');
    String noteJsonString = newNote.toJsonString();

    await flutterLocalNotificationsPlugin.show(
        0, 'plain title', 'plain body', platformChannelSpecifics,
        payload: noteJsonString);

Next you get the payload string in your onSelectNotification method and use the fromJsonString constructor (which decodes the json string and creates a Note object) to get the Note object:

    Future onSelectNotification(String payload) async {
        Note note = Note.fromJsonString(payload);
        //You can then use your Note object however you want.
        //e.g
        print(note.title);  // Hello
        print(note.description); // This is my first reminder

    }

Comments

[Wei Jun]

Hi Victor, thanks for the suggestion! I have just tested it out and I am able to set the reminder without any error! I would have never thought of encoding it to a String object. Thanks!