rog_app/lib/services/location_line_service.dart

import 'package:geojson/geojson.dart';
import 'package:http/http.dart' as http;

import '../utils/const.dart';

class LocationLineService {
  static Future<GeoJsonFeature?> loadLocationLines() async {
    final geo = GeoJson();
    GeoJsonFeature? fs;
    String serverUrl = ConstValues.currentServer();
    String url = '$serverUrl/api/location_line/';
    //print('++++++++$url');
    final response = await http.get(
      Uri.parse(url),
      headers: <String, String>{
        'Content-Type': 'application/json; charset=UTF-8',
      },
    );

    if (response.statusCode == 200) {
      geo.processedFeatures.listen((fst) {
        fs = fst;
      });

      await geo.parse(response.body, verbose: true);

      return fs;
    } else {
      throw Exception('Failed to create album.');
    }
  }
}