post request complex json to api in flutter

Question

i have this json i want to post to an api but i am not sure how it is done ..this is how the request looks like :

  {
    "products": [
        {"id":1, "qty": 1},{"id":2, "qty": 1}
    ],
    "vendor_id": 1,
    "notes": " ",
    "address": ""
}

and this is the request class that i used to map the request :

    class Order{

  int vendor_id;
  String address ,notes ;
  List<OrderProduct> products;

  Order({this.products , this.address , this.notes , this.vendor_id});

  Map<String, dynamic> toMap() {
    return {
      'vendor_id': vendor_id,
      'address': address,
      'notes': notes,
      'products': products,
    };
  }


}

class OrderProduct{
  int id , qty ;
  OrderProduct({this.id , this.qty});
  Map<String, dynamic> toMap() {
    return {
      'id': id,
      'qty': qty,
    };
  }
}

what am i missing out ?

Answer 1

Json that I have posted in body..

{
       "products": [
          {"id":1, "qty": 1},{"id":2, "qty": 1}
       ],
       "vendor_id": 1,
       "notes": " ",
       "address": ""
    }

Your Post Api call be like:

Future<Order> postOrder(int vendor_id, String notes, String address, int 
 id1,int q1, int id2, int q2) async {

 Paste your api url here
 String url = '';
 final response = await http.post(apiUrl, headers: {
   // Enter your headers parameter if needed
   //  E.g: 
  'Authorization' : 'xyz',
  'Content-Type' : 'application/json'
 },
body: jsonEncode(<String, String>{
  'vendor_id' : vendor_id,
  'notes' : notes,
  'address' : address,
  'products' : [
   {'id': id1,'qty' : q1},
   {'id' : id2,'qty' : q2}
  ]
}));

  if (response.statusCode == 200) {
    var data = jsonDecode(response.body.toString());
    print(data);
     return Order.fromJson(jsonDecode(response.body));
   } else {
  throw Exception('Failed to post user.');
  }
 }

Your model be like:

class Order {
    List<Products>? products;
     int? vendorId;
     String? notes;
     String? address;

Order({this.products, this.vendorId, this.notes, this.address});

Order.fromJson(Map<String, dynamic> json) {
   if (json['products'] != null) {
     products = <Products>[];
     json['products'].forEach((v) {
       products!.add(new Products.fromJson(v));
     });
    }
    vendorId = json['vendor_id'];
    notes = json['notes'];
    address = json['address'];
  }

 Map<String, dynamic> toJson() {
   final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.products != null) {
      data['products'] = this.products!.map((v) => v.toJson()).toList();
    }
    data['vendor_id'] = this.vendorId;
    data['notes'] = this.notes;
    data['address'] = this.address;
    return data;
  }
 }

  class Products {
    int? id;
    int? qty;

    Products({this.id, this.qty});

    Products.fromJson(Map<String, dynamic> json) {
       id = json['id'];
       qty = json['qty'];
    }
 
     Map<String, dynamic> toJson() {
       final Map<String, dynamic> data = new Map<String, dynamic>();
          data['id'] = this.id;
          data['qty'] = this.qty;
          return data;
        }
     }

Answer 2

Just Do it like json.encode(myArr), for example

 Map<String, String> params = {
      "mobile": userNameController.text,
      "password": passwordController.text,
      "deviceid": '${fcmToken}',
    };

 Future<String> postRequest(var url, {var postParams}) async {
    return http
        .post(url, body: json.encode(postParams))// do json encoding here 
        .then((http.Response response) {
      final int statusCode = response.statusCode;
      print("postParams " + json.encode(postParams));
      print("statusCode " + '${statusCode} ${response.body}');
      if (statusCode < 200 || statusCode > 400 || json == null) {
        throw new Exception("Error while fetching data");
      }
      print(response.request);
      return response.body;
    });
  }