The return type 'List<HospitalListModel>' isn't a 'HospitalListModel', as required by the closure's context

Question

I got an error when I try to fix the error on my ApiProvider, this is my ApiProvider:

class ApiProvider {
  final Dio _dio = Dio();
  final String _url = 'http://lovemonster.my.id/hospital';

  Future<List<HospitalListModel>> fetchHospitalList() async {
    try {
      List<HospitalListModel> hospitalList = [];
      Response response = await _dio.get(_url);
      var mData = response.data as List;
      hospitalList =  mData.map<HospitalListModel>((e) => hospitalListModelFromJson(e))
          .toList();
          return hospitalList;//return List not object
      } catch (error, stacktrace) {
        print("Exception occurred: $error stackTrace: $stacktrace");
        return Future.error("");
      }
    }

and the error is on hospitalListModelFromJson(e), it related to hospitalListModelFromJson from my model, i just want to create a listview from this API http://lovemonster.my.id/hospital, this is my model:

List<HospitalListModel> hospitalListModelFromJson(String str) => List<HospitalListModel>.from(json.decode(str).map((x) => HospitalListModel.fromJson(x)));

String hospitalListModelToJson(List<HospitalListModel> data) => json.encode(List<dynamic>.from(data.map((x) => x.toJson())));

class HospitalListModel {
  HospitalListModel({
    this.id,
    this.title,
    this.content,
    this.image,
    this.phone,
    this.coordinates,
    this.website,
    this.createdAt,
    this.updatedAt,
  });

  dynamic id;
  dynamic title;
  dynamic content;
  dynamic image;
  dynamic phone;
  dynamic coordinates;
  dynamic website;
  dynamic createdAt;
  dynamic updatedAt;

  factory HospitalListModel.fromJson(Map<String, dynamic> json) => HospitalListModel(
    id: json["id"],
    title: json["title"],
    content: json["content"],
    image: json["image"],
    phone: json["phone"],
    coordinates: json["coordinates"],
    website: json["website"],
    createdAt: json["created_at"],
    updatedAt: json["updated_at"],
  );

  Map<String, dynamic> toJson() => {
    "id": id,
    "title": title,
    "content": content,
    "image": image,
    "phone": phone,
    "coordinates": coordinates,
    "website": website,
    "created_at": createdAt.toIso8601String(),
    "updated_at": updatedAt.toIso8601String(),
  };
}

if you know how to fetch the model into list or you know how to fix the error, please let me know

Answer 1

You need to change these:

var mData = response.data as List;
hospitalList =  mData.map<HospitalListModel>((e) => hospitalListModelFromJson(e))
          .toList();

to this:

hospitalList = hospitalListModelFromJson(response.data)

Fist of all you api response is not list is encoded list, second you convert it twice into the list and this is cause the issue.

edit:

change this :

List<HospitalListModel> hospitalListModelFromJson(String str) => List<HospitalListModel>.from(json.decode(str).map((x) => HospitalListModel.fromJson(x)));

to this:

List<HospitalListModel> hospitalListModelFromJson(List<Map<String, dynamic>> data) => List<HospitalListModel>.from(data.map((x) => HospitalListModel.fromJson(x)));

from your second error, it seems your api response isn't encoded so you don't need to decode it.