'StreamSubscription<LocationData>' cannot be assigned to 'StreamSubscription<Map<String, double>>' - dart

Question

Currently learning Flutter and got this error while trying to detect the location of my device:
A value of type 'StreamSubscription' can't be assigned
to a variable of type 'StreamSubscription>'
I was following an online tutorial but somehow got this error.
import 'package:flutter/material.dart';
import 'package:flutter_map/flutter_map.dart';
import 'package:location/location.dart';
import 'dart:async';
import 'package:flutter/services.dart';
class MainPage extends StatefulWidget {
#override
State<StatefulWidget> createState() => AppState();
}
class AppState extends State<MainPage> {
Map<String,double> currentLocation = new Map();
StreamSubscription<Map<String,double>> locationSubscription;
var location = new Location();
String error;
void initState() {
super.initState();
currentLocation['latitude'] = 0.0;
currentLocation['longitude'] = 0.0;
initPlatformState();
locationSubscription =
location.onLocationChanged().listen((Map<String,double> result) {
setState(() {
currentLocation = result;
});
});
}
void initPlatformState() async{
Map<String,double> myLocation;
try {
myLocation = await location.getLocation();
error="";
} on PlatformException catch(e) {
if(e.code == 'PERMISSION_DENIED')
error = "permission denied";
else if(e.code == "PERMISSION_DENIED_NEVER_ASK")
error = "permission denied";
myLocation = null;
}
setState(() {
currentLocation = myLocation;
});
}
#override
Widget build (BuildContext context) {
return Scaffold(
appBar: AppBar(
centerTitle: true,
title: Text(""),
automaticallyImplyLeading: false,
),
body: Container(
child: FlutterMap(
options: MapOptions(
),
layers: [
TileLayerOptions(
),
]
),
)
);
}
}
I would be very grateful for any advice. Here is the video I followed: https://www.youtube.com/watch?v=K4nYTayjofY&t=321s

Answer 1

Looks like the tutorial was done using an older version of the location plugin, since v2.0.0 they changed the api to return structured data rather than a map.
https://github.com/Lyokone/flutterlocation/blob/master/CHANGELOG.md
So you'd need to either change all your Map<String, double> types to LocationData or set your plugin version to ^1.4.0.

Answer 2

I tried many ways till I found this way thanks to a kind person who helped on another flutter facebook group.Make sure in your pubspec.yaml you update location to the latest version
dependencies:
location: ^2.3.5
Then change it to the following code:
LocationData _currentLocation;
StreamSubscription<LocationData> _locationSubscription;
var _locationService = new Location();
String error;
void initState() {
super.initState();
initPlatformState();
_locationSubscription = _locationService
.onLocationChanged()
.listen((LocationData currentLocation) async {
setState(() {
_currentLocation = currentLocation;
});
});
}
void initPlatformState() async {
try {
_currentLocation = await _locationService.getLocation();
} on PlatformException catch (e) {
if (e.code == 'PERMISSION_DENIED') {
error = 'Permission denied';
}else if(e.code == "PERMISSION_DENIED_NEVER_ASK"){
error = 'Permission denied';
}
_currentLocation = null;
}
You may access longitude and latitude as
_currentLocation.longitude and _currentLocation.latitude
these will return double values. Also, there are more options available at
https://pub.dev/packages/location#-readme-tab-