I have a Map which stores an API response that I intend to use throughout my Application. Although, the API part works just as I expected, the trouble begins when I try displaying the total amount of all the objects. The total amount needs to be calculated in the following way:total += product_selling_price * quantity;.
However, the logic that I have written throws the below error:
Class 'int' has no instance method '[]'.
Receiver: 0
Tried calling: []("product_selling_price")
The JSON response, the method that calculates the total and the widget from which the method is called are as follows. Also, I will mark the lines where the errors are pointed at.
The JSON response:
{
"status": "success",
"data": [
{
"cart_id": 18,
"restaurant_id": "1",
"product_id": "5",
"restaurant_name": "City Club",
"product_name": "Palak Paneer",
"product_description": "Tasty silky gravy with goodness of palak",
"product_image": "/public/assets/product/C6pGz101-42-17.jpg",
"product_selling_price": "180",
"product_status": "active",
"product_quantity": "32",
"quantity": "2"
},
{
"cart_id": 17,
"restaurant_id": "1",
"product_id": "6",
"restaurant_name": "City Club",
"product_name": "Jersey Burger",
"product_description": "Tasty yummy burgir. BURGIRRRRR",
"product_image": "/public/assets/product/1Xf0sr01-43-20.jpg",
"product_selling_price": "185",
"product_status": "active",
"product_quantity": "50",
"quantity": "2"
},
{
"cart_id": 16,
"restaurant_id": "1",
"product_id": "7",
"restaurant_name": "City Club",
"product_name": "Tibetan Soup",
"product_description": "Healthy Soup from the mountains of Tibet",
"product_image": "/public/assets/product/CgMBpm02-03-38.jpg",
"product_selling_price": "120",
"product_status": "active",
"product_quantity": "24",
"quantity": "2"
}
]
}
The class with the method:
class CartItemProvider with ChangeNotifier {
Map<String, dynamic> _cartItems = {};
List<dynamic> _individualItems = [];
Network network = Network();
String baseUrl = 'https://achievexsolutions.in/current_work/eatiano/';
double deliveryCost = 40;
double discountCost = 50;
List<dynamic> get cartItemList {
return [..._cartItemList];
}
Map<String, dynamic> get cartItems {
return {..._cartItems};
}
Future<void> fetchCartItems() async {
SharedPreferences localStorage = await SharedPreferences.getInstance();
final url = Uri.parse(baseUrl + 'api/auth/cart');
final response = await http.get(url, headers: {
'Authorization': 'Bearer ${localStorage.getString('token')}',
'Accept': 'application/json'
});
Cart cartJson = cartFromJson(response.body);
_cartItems = cartJson.toJson();
print('Cart Item $_cartItems');
}
double get itemAmount { //The method in question
double total = 0.0;
total = _cartItems['data'].fold( //The above error gets pointed from this line
0,
(price, value) =>
price +
(double.parse(price['product_selling_price']) * //To This line, at price['product_selling_price']
double.parse(price['quantity'])));
return total;
}
}
The Model Class in case someone needs to take a look:
import 'package:meta/meta.dart';
import 'dart:convert';
Cart cartFromJson(String str) => Cart.fromJson(json.decode(str));
String cartToJson(Cart data) => json.encode(data.toJson());
class Cart {
Cart({
required this.status,
required this.data,
});
final String status;
final List<Datum> data;
factory Cart.fromJson(Map<String, dynamic> json) => Cart(
status: json["status"],
data: List<Datum>.from(json["data"].map((x) => Datum.fromJson(x))),
);
Map<String, dynamic> toJson() => {
"status": status,
"data": List<dynamic>.from(data.map((x) => x.toJson())),
};
}
class Datum {
Datum({
required this.cartId,
required this.restaurantId,
required this.productId,
required this.restaurantName,
required this.productName,
required this.productDescription,
required this.productImage,
required this.productSellingPrice,
required this.productStatus,
required this.productQuantity,
required this.quantity,
});
final int cartId;
final String restaurantId;
final String productId;
final String restaurantName;
final String productName;
final String productDescription;
final String productImage;
final String productSellingPrice;
final String productStatus;
final String productQuantity;
final String quantity;
factory Datum.fromJson(Map<String, dynamic> json) => Datum(
cartId: json["cart_id"],
restaurantId: json["restaurant_id"],
productId: json["product_id"],
restaurantName: json["restaurant_name"],
productName: json["product_name"],
productDescription: json["product_description"],
productImage: json["product_image"],
productSellingPrice: json["product_selling_price"],
productStatus: json["product_status"],
productQuantity: json["product_quantity"],
quantity: json["quantity"],
);
Map<String, dynamic> toJson() => {
"cart_id": cartId,
"restaurant_id": restaurantId,
"product_id": productId,
"restaurant_name": restaurantName,
"product_name": productName,
"product_description": productDescription,
"product_image": productImage,
"product_selling_price": productSellingPrice,
"product_status": productStatus,
"product_quantity": productQuantity,
"quantity": quantity,
};
}
The widget from which the itemAmount getter is called:
class CartDetailScreen extends StatefulWidget {
CartDetailScreenState createState() => CartDetailScreenState();
}
class CartDetailScreenState extends State<CartDetailScreen> {
@override
Widget build(BuildContext context) {
......
// TODO: implement build
return Scaffold(
......
body: ListView(
children: [
........
),
Text(
'₹ ${Provider.of<CartItemProvider>(context).itemAmount //This is where the itemAmount method is accessed from
}',
........
],
));
}
}
I would like to know what I need to do to fix and get rid of this error.
