String baseUrl = 'https://api.mapbox.com/geocoding/v5/mapbox.places';
String accessToken = dotenv.env['MAPBOX_ACCESS_TOKEN']!;

Dio _dio = Dio();

Future getReverseGeocodingGivenLatLngUsingMapbox(LatLng latLng) async {
  String query = '${latLng.longitude},${latLng.latitude}';
  String url = '$baseUrl/$query.json?access_token=$accessToken';
  url = Uri.parse(url).toString();
  print(url);
  try {
    _dio.options.contentType = Headers.jsonContentType;
    final responseData = await _dio.get(url);
    return responseData.data;
  } catch (e) {
    final errorMessage = DioExceptions.fromDioError(e as DioError).toString();
    debugPrint(errorMessage);
  }
}

Using the above function below

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 then using the above function below:

void initializeLocationAndSave() async {
   
   LatLng currentLocation = getCurrentLatLngFromSharedPrefs();
   String currentAddress =
    (await getParsedReverseGeocoding(currentLocation))['place'];
}

 LatLng getCurrentLatLngFromSharedPrefs() {

    return LatLng(sharedPreferences.getDouble('latitude')!,   
    sharedPreferences.getDouble('longitude')!);
 }

However, I am unable to retrieve the currentAddress value. The following error is shown:

Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'String'

Where I am going wrong? I am using code from here by following the youtube tutorial

CodePudding user response：

Dio does decoding automatically, just remove json.decode.

The default value is JSON, dio will parse response string to json object automatically when the content-type of response is 'application/json'.