mobile-app/lib/data/repository/repository.dart

import 'package:farm_tpf/data/api/dio_provider.dart';
import 'package:farm_tpf/data/api/rest_client.dart';
import 'package:farm_tpf/models/PagedResult.dart';
import 'package:farm_tpf/models/Plot.dart';
import 'package:farm_tpf/models/user.dart';
import 'package:farm_tpf/models/user_request.dart';
import 'package:farm_tpf/utils/const_common.dart';

class Repository {
  final dio = DioProvider.instance();

  Future<User> signInWithCredentials(String username, String password) {
    final client = RestClient(dio);
    return client.login(UserRequest(username: username, password: password));
  }

  Future<PagedResult<T>> getInfinityList<T>(String url,
      {int page = 0, int size = 20}) async {
    var initUrl = "/api/activities/latest-env-by-activity-type/1/2";
    var url =
        ConstCommon.baseUrl + initUrl + "?page=$page&paged=true&size=$size";
    var response = await dio.get(url);

    final value = PagedResult<T>.fromJson(response.data, getInstanceClass());
    return value;
  }

  Object getInstanceClass() {
    var instanceClass;
    if (1 == 1) {
      instanceClass = new Plot();
    }
    return instanceClass;
  }
}