Flutter Place Order Model for E-commerce App

The below code is for your place order model. The code is use in the app for food delivery

class PlaceOrderBody {
   List<CartItem>? _cart;
  late double _orderAmount;
  late String _orderNote;
  late double _distance;
  late String _address;
  late String _latitude;
  late String _longitude;
  late  String _contactPersonName;
  late String _contactPersonNumber;

  PlaceOrderBody(
      {required List<CartItem> cart,
        required double orderAmount,
        required double distance,
        required String scheduleAt,
        required String orderNote,
        required String address,
        required String latitude,
        required String longitude,
        required String contactPersonName,
        required String contactPersonNumber,
      }){
    this._cart = cart;
    this._orderAmount = orderAmount;
    this._orderNote = orderNote;
    this._distance = distance;
    this._address = address;
    this._latitude = latitude;
    this._longitude = longitude;
    this._contactPersonName = contactPersonName;
    this._contactPersonNumber = contactPersonNumber;
  }

  List<CartItem> get cart => _cart!;

  double get orderAmount => _orderAmount;

  String get orderNote => _orderNote;

  double get distance => _distance;

  String get address => _address;
  String get latitude => _latitude;
  String get longitude => _longitude;
  String get contactPersonName => _contactPersonName;
  String get contactPersonNumber => _contactPersonNumber;

  PlaceOrderBody.fromJson(Map<String, dynamic> json) {
    if (json['cart'] != null) {
      _cart = [];
      json['cart'].forEach((v) {
        _cart!.add(new CartItem.fromJson(v));
      });
    }

    _orderAmount = json['order_amount'];

    _orderNote = json['order_note'];

    _distance = json['distance'];

    _address = json['address'];
    _latitude = json['latitude'];
    _longitude = json['longitude'];
    _contactPersonName = json['contact_person_name'];
    _contactPersonNumber = json['contact_person_number'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();

    if (this._cart != null) {
      data['cart'] = this._cart!.map((v) => v.toJson()).toList();
    }
    data['order_amount'] = this._orderAmount;
    data['order_note'] = this._orderNote;
    data['distance'] = this._distance;
    data['address'] = this._address;
    data['latitude'] = this._latitude;
    data['longitude'] = this._longitude;
    data['contact_person_name'] = this._contactPersonName;
    data['contact_person_number'] = this._contactPersonNumber;
    return data;
  }

}