Flutter: How to store the location data? - flutter

Question

Errors:
The named parameter 'locationData' is required, but there's no
corresponding argument. Try adding the required argument.
Undefined name 'locationData'. Try correcting the name to one that is defined, or defining the name.
The location data in the main.dart file bring an error please help me solve it.
My code:
Below is the main.dart code that caused the error:
import 'package:firebase_core/firebase_core.dart';
import 'package:firstapp/screens/Login_screen.dart';
import 'package:firstapp/screens/authunication/phone_auth_screen.dart';
import 'package:firstapp/screens/home_screen.dart';
import 'package:firstapp/screens/location_screen.dart';
import 'package:firstapp/screens/splash_screen.dart';
import 'package:flutter/material.dart';
import 'package:location/location.dart';
Future<void> main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(MyApp());
}
// ignore: use_key_in_widget_constructors
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
theme: ThemeData(
primaryColor: Colors.cyan.shade900,
),
initialRoute: SplashScreen.id,
routes: {
SplashScreen.id: (context) => SplashScreen(),
LoginScreen.id: (context) => LoginScreen(),
PhoneAuthScreen.id: (context) => PhoneAuthScreen(),
LocationScreen.id: (context) => LocationScreen(),
HomeScreen.id: (context) => HomeScreen(locationData),
},
);`
Below is the code for the HomeScreen widget where I want location data:
import 'package:flutter/material.dart';
import 'package:location/location.dart';
class HomeScreen extends StatelessWidget {
static const String id = 'home-screen';
final LocationData locationData;
HomeScreen({
required this.locationData,
});
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(locationData.latitude.toString()),
),
body: Center(
child: Text('Home screen'),
),
);
}
}
Here is the code for the LocationScreen widget in the app:
import 'package:firebase_auth/firebase_auth.dart';
import 'package:firstapp/screens/login_screen.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:location/location.dart';
class LocationScreen extends StatefulWidget {
static const String id = 'location-screen';
#override
State<LocationScreen> createState() => _LocationScreenState();
}
class _LocationScreenState extends State<LocationScreen> {
Location location = new Location();
late bool _serviceEnabled;
late PermissionStatus _permissionGranted;
late LocationData _locationData;
Future<LocationData?>getLocation() async {
_serviceEnabled = await location.serviceEnabled();
if (!_serviceEnabled) {
_serviceEnabled = await location.requestService();
if (!_serviceEnabled) {
return null;
}
}
_permissionGranted = await location.hasPermission();
if (_permissionGranted == PermissionStatus.denied) {
_permissionGranted = await location.requestPermission();
if (_permissionGranted != PermissionStatus.granted) {
return null;
}
}
_locationData = await location.getLocation();
return _locationData;
}

Answer 1

So,
The first error says that when you try to implement a HomeScreen widget, withoug giving the required parameter named locationData,to give the required parameted follow this code example:
HomeScreen(locationData: locationData)
The second error says that you are trying to use a variable that is not defined yet. In the page that you try to implement the HomeScreen widget, you should define a variable named locationData, to give it a value and then to try to use the HomeScreen widget. For instance:
class LocationScreen extends StatefulWidget {
const LocationScreen({Key? key}) : super(key: key);
#override
State<LocationScreen> createState() => _LocationScreenState();
}
class _LocationScreenState extends State<LocationScreen> {
LocationData locationData;
#override
Widget build(BuildContext context) {
//in case that you use the HomeScreen as a widget
return locationData == null ? Container() : HomeScreen(locationData: locationData);
//in case that you use the HomeScreen as Screen
return Container();
}
void getLocationData() async{
//in case that you use the HomeScreen as a widget
//this function will change the state after the locationData have been filled
locationData = await getLocation();
setState(() {
});
}
void navigateToHomeScreen() async{
//in case that you use the HomeScreen as a widget
//this function will change the state after the locationData have been filled
locationData = await getLocation();
Navigator.push(context, MaterialPageRoute(
builder: (context) => HomeScreen(locationData: locationData);
));
}
Future<LocationData?> getLocation() async {
_serviceEnabled = await location.serviceEnabled();
if (!_serviceEnabled) {
_serviceEnabled = await location.requestService();
if (!_serviceEnabled) {
return null;
}
}
_permissionGranted = await location.hasPermission();
if (_permissionGranted == PermissionStatus.denied) {
_permissionGranted = await location.requestPermission();
if (_permissionGranted != PermissionStatus.granted) {
return null;
}
}
_locationData = await location.getLocation();
return _locationData;
}
}
The third error says that don't use any Positional parameters in your HomeScreen class because you use named parameters, If you follow my code, it will be fixed as well
Hope I helped,
Enjoy flutter

Answer 2

On the HomeScreen, replace this line of code:
HomeScreen({required this.locationData,});
with
HomeScreen(this.locationData);
This should clear the error on main.dart