Flutter : How put received data on model as nested List

Question

I am trying to create shopping app by flutter and Laravel for backend ,I created the backend at tested it on postman and worked correctly ,now I want to design the UI by flutter depend on data's come from API ,First of all I want to view all categories and all products of each category ,I receive data from API as this :

[
    {
        "id": 1,
        "name": "cars",
        "created_at": "-000001-11-30T00:00:00.000000Z",
        "updated_at": null,
        "product": [
            {
                "id": 1,
                "product_name": "mercides",
                "category_id": 1,
                "price": "120000",
                "sale": "0",
                "created_at": null,
                "updated_at": null
            },
        ]
    },
]

I made a class in model folder to put data on it :

import 'dart:convert';

List<Categories> categoriesFromMap(String str) =>
    List<Categories>.from(json.decode(str).map((x) => Categories.fromMap(x)));

String categoriesToMap(List<Categories> data) =>
    json.encode(List<dynamic>.from(data.map((x) => x.toMap())));

class Categories {
  Categories({
    this.id,
    this.name,
    this.product,
  });

  final int id;
  final String name;

  final List<Product> product;

  factory Categories.fromMap(Map<String, dynamic> json) => Categories(
        id: json["id"],
        name: json["name"],
        product:
            List<Product>.from(json["product"].map((x) => Product.fromMap(x))),
      );

  Map<String, dynamic> toMap() => {
        "id": id,
        "name": name,
        "product": List<dynamic>.from(product.map((x) => x.toMap())),
      };
}

class Product {
  Product({
    this.id,
    this.productName,
    this.categoryId,
    this.price,
    this.sale,
  });

  final int id;
  final String productName;
  final int categoryId;
  final String price;
  final String sale;

  factory Product.fromMap(Map<String, dynamic> json) => Product(
        id: json["id"],
        productName: json["product_name"],
        categoryId: json["category_id"],
        price: json["price"],
        sale: json["sale"],
      );

  Map<String, dynamic> toMap() => {
        "id": id,
        "product_name": productName,
        "category_id": categoryId,
        "price": price,
        "sale": sale,
      };
}

Now I want to receive data from URL and convert it as Future List in this function :

  Future<List> get_data() async {
    var url = 'http://10.0.2.2:8000/api/user/cats_view';
    var response = await http.get(url);
    var data = jsonDecode(response.body);
  }

How can I do it , How can I use categoriesToMap() function on class or any other way?

Solution

You could use the categoriesFromMap function to convert the response body into a list of Categoriess. I have included a minimum working example of the get_data function:

Future<List<Categories>> get_data() async {
  var url = 'http://10.0.2.2:8000/api/user/cats_view';
  var response = await http.get(url);
  var data = categoriesFromMap(response.body);
}

See the documentation here for more information regarding deserializing responses.

Comments

[Sermed mayi]

Thank you I will see the documentation ,it works correctly