Flutter MapBox - Unhandled Exception: type 'Null' is not a subtype of type

Question

I am just following this guide https://github.com/Imperial-lord/mapbox-flutter, In turn by turn navigation, getting error like 'Unhandled Exception: type 'Null' is not a subtype of type 'String' - In emulator i am getting error like

Syncing files to device iPhone 13... flutter: flutter: Oops something went wrong [VERBOSE-2:ui_dart_state.cc(209)] Unhandled Exception: type 'Null' is not a subtype of type 'String' #0 getParsedReverseGeocoding (package:t..helpers/mapbox_handler.dart:42:19) <asynchronous suspension> #1 _SplashState.initializeLocationAndSave (package:../screens/authentication/splash.dart:48:10) <asynchronous suspension>

    
 ``

In this page getParsedReverseGeocoding 
Future<Map> getParsedReverseGeocoding(LatLng latLng) async {
  var response =
      json.decode(await getReverseGeocodingGivenLatLngUsingMapbox(latLng));
  Map feature = response['features'][0];
  Map revGeocode = {
    'name': feature['text'],
    'address': feature['place_name'].split('${feature['text']}, ')[1],
    'place': feature['place_name'],
    'location': latLng
  };
  return revGeocode;
}

and

 void initializeLocationAndSave() async {
// Ensure all permissions are collected for Locations
Location _location = Location();
bool? _serviceEnabled;
PermissionStatus? _permissionGranted;

_serviceEnabled = await _location.serviceEnabled();
if (!_serviceEnabled) {
  _serviceEnabled = await _location.requestService();
}

_permissionGranted = await _location.hasPermission();
if (_permissionGranted == PermissionStatus.denied) {
  _permissionGranted = await _location.requestPermission();
}

// Get the current user location
LocationData _locationData = await _location.getLocation();
LatLng currentLocation =
    LatLng(_locationData.latitude!, _locationData.longitude!);

// Get the current user address
String currentAddress =
    (await getParsedReverseGeocoding(currentLocation))['place'];

// Store the user location in sharedPreferences
sharedPreferences.setDouble('latitude', _locationData.latitude!);
sharedPreferences.setDouble('longitude', _locationData.longitude!);
sharedPreferences.setString('current-address', currentAddress);

Navigator.pushAndRemoveUntil(context,
    MaterialPageRoute(builder: (_) => const Home()), (route) => false);

}

Answer 1

From the error message, you are passing in a null value instead of a String value. Adding a null check while passing this value should help you solve this problem. For example:

Text(value ?? "Value if null is passed");