CODEWITHSUNDEEP
dart
Long
Long

Reputation: 59

Why it returns Instance of instead of the value?

Why the getCurrencyFromAPI function returns Intance of currency instead of the value itself. Is there some thing wrong with my model class?

This is the function

import 'dart:convert';
import 'package:app_bloc/data/models/currency.dart';
import 'package:http/http.dart' as http;
import 'package:app_bloc/constants/api_urls.dart';

class Repository {
  Future<dynamic> getCurrencyFromAPI() async {
    final res = await http.get(Uri.parse(coinbaseURL));

    if (res.statusCode == 200) {
      final resData = jsonDecode(res.body);

      final data = resData['data'] as List;
      List<Currency> list = [];
      for (var e in data) {
        final a = Currency.fromJson(e);
        list.add(a);
      }
      print(list);
    } else {
      throw Exception('Error fetching data from API');
    }
  }
}

void main(List<String> args) {
  Repository repo = Repository();
  repo.getCurrencyFromAPI();
}

this is the model class

class Currency {
  String id;
  String name;
  String minSize;

  Currency({required this.id, required this.name, required this.minSize});

  factory Currency.fromJson(Map<String, dynamic> data) {
    final id = data['id'] as String;
    final name = data['name'] as String;
    final minSize = data['min_size'] as String;
    return Currency(id: id, name: name, minSize: minSize);
  }
}

Upvotes: 0

Views: 43

Answers (2)

lrn
lrn

Reputation: 71693

Your Currency class does not have a toString method. That means it inherits the default from Object which returns Instance of 'Currency'.

When you print the List<Currency> it calls toString on every element to get a string representation. So, that's what you see. It is a Currency object.

Try adding:

  String toString() => "Currency(id: $id, name: $name, minSize: $minSize)";

to you Currency class and see if it makes a difference.

Upvotes: 1

Tasnuva Tavasum oshin
Tasnuva Tavasum oshin

Reputation: 4750

Currency currencyModelFromJson(String str) => Currency.fromJson(json.decode(str));

class Currency {
  String id;
  String name;
  String minSize;

  Currency({required this.id, required this.name, required this.minSize});

  factory Currency.fromJson(Map<String, dynamic> data) {
    final id = data['id'] as String;
    final name = data['name'] as String;
    final minSize = data['min_size'] as String;
    return Currency(id: id, name: name, minSize: minSize);
  }
}

Then do this :

class Repository {
  Future<dynamic> getCurrencyFromAPI() async {
    final res = await http.get(Uri.parse(coinbaseURL));

    if (res.statusCode == 200) {
      final resData = jsonDecode(res.body);

      final data = resData['data'] as List;
      List<Currency> list = [];
      for (var e in data) {
        final a = currencyModelFromJson(e); // change here 
        list.add(a);
      }
      print(list);
    } else {
      throw Exception('Error fetching data from API');
    }
  }
}

Upvotes: 0

Related Questions