How Can action be triggered by changing object status? - flutter

Question

I have order which have 4 status : preparing , pending , delivering and delivered. and when the order status changed from one to another I wanted to show a notification to the user of the change occurs.
*I have used local notifications plugin. In order page widget shown here it is triggered by a stream above that get the order from fire-base.
*That's why I supposed that each time the status will change the orderPage will be rebuild again and initstate will be recalled and send the new notification msg with new status, but that didn't happen.
Another solution was to use didchangedependency but I got no different result.
This was a missed work I know, but this is what came to my mind.
*What I exactly want is something that make me listen on the status and when changes occur a function " singleNotification" will be called to show the notification.
any Help will be appreciated.
class OrderPage extends StatefulWidget {
const OrderPage({
Key key,
#required this.order,
}) : super(key: key);
final Order order;
#override
OrderPageState createState() {
return new OrderPageState();
}
}
class OrderPageState extends State<OrderPage> {
final DateTime now = DateTime.now().toUtc().add(
Duration(seconds: 3),
);
String title = "notification";
String msg = "";
FlutterLocalNotificationsPlugin localNotificationsPlugin =
FlutterLocalNotificationsPlugin();
initializeNotifications() async {
var initializeAndroid =
AndroidInitializationSettings('#mipmap/ic_launcher');
var initializeIOS = IOSInitializationSettings();
var initSettings = InitializationSettings(initializeAndroid, initializeIOS);
await localNotificationsPlugin.initialize(initSettings);
}
Future singleNotification(
DateTime datetime, String message, String subtext, int hashcode,
{String sound}) async {
var androidChannel = AndroidNotificationDetails(
'channel-id',
'channel-name',
'channel-description',
importance: Importance.Max,
priority: Priority.Max,
);
var iosChannel = IOSNotificationDetails();
var platformChannel = NotificationDetails(androidChannel, iosChannel);
localNotificationsPlugin.schedule(
hashcode, message, subtext, datetime, platformChannel,
payload: hashcode.toString());
}
#override
void initState() {
super.initState();
getMsgState(widget.order.status);
initializeNotifications();
singleNotification(
now,
title,
msg,
98123871,
);
}
#override
void didChangeDependencies() {
super.didChangeDependencies();
getMsgState(widget.order.status);
initializeNotifications();
singleNotification(
now,
title,
msg,
98123871,
);
}
Widget build(BuildContext context) {
return Container();
}
String getMsgState(String orderStatus) {
switch (orderStatus) {
case 'pending':
return msg = "Your order is pending";
break;
case 'preparing':
return msg = "your order is currently preparing";
break;
case 'delivering':
return msg = "your order is currently delivering";
break;
case 'delivered':
return msg = "Your order is delivered";
default:
return msg = "CustomStepState.Complete";
break;
}
}

Answer 1

If I understand correctly, Firebase knows when the order status is changed. And it sends a notification. And you would like to show it to the user.
You can use FCM and Firebase in-app notification. One of my project had a similar requirement whether server does the processing and the Flutter mobile app shows the status. I did the following :
Wrote a small code on the server side which calls Firebase cloud message API with user display message and data payload.
Wrote a code on Flutter mobile app side to display the notification (in the in-app style) if the app is already in the foreground.
Sample code snippet :
_firebaseMessaging.configure(
onMessage: (Map<String, dynamic> message) async {
Helper.write('on message $message');
//Map data = json.decode(message);
this.scaffoldKey.currentState.showSnackBar(SnackBar(content: Text(message['aps']['alert']['body']),));
},
onResume: (Map<String, dynamic> message) async {
Helper.write('on resume $message');
},
onLaunch: (Map<String, dynamic> message) async {
Helper.write('on launch $message');
},
);
analytics.logEvent(name:'firebaseCloudMessaging_Listeners_Done',parameters:null);
}