Unsupported operation: Platform._operatingSystem

Hi Developers,

I have developed a Flutter project with the following dependencies:

environment:
  sdk: '>=2.12.0 <3.0.0'

dependencies:
  flutter:
    sdk: flutter

  cupertino_icons: ^1.0.2
  http: ^0.13.1
  provider: ^5.0.0
  audioplayers: ^0.18.2
  font_awesome_flutter: any
  google_fonts: 4.0.4
  dob_input_field: any
  fluttertoast: any
  razorpay_flutter: 1.3.2

dev_dependencies:
  flutter_test:
    sdk: flutter

flutter:
  uses-material-design: true

I am trying to add Razorpay payment gateway for the cart screen. The cart screen code is as follows:

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
import 'package:fluttertoast/fluttertoast.dart';
import 'package:razorpay_flutter/razorpay_flutter.dart';

Future<Cart> fetchCartItems() async {
  final response = await http
      .get(Uri.parse('https://lobster-app-et3xm.ondigitalocean.app/api/cart/'));

  if (response.statusCode == 200) {
    // If the server did return a 200 OK response,
    // then parse the JSON.
    var respBody = jsonDecode(response.body);

    return Cart.fromJson(respBody['data']);
  } else {
    // If the server did not return a 200 OK response,
    // then throw an exception.
    throw Exception('Failed to load cart');
  }
}

class Cart {

  String name, price;

  Cart({
    required this.name,
    required this.price,
  });

  factory Cart.fromJson(List<dynamic> json) {

  if(json!=null){
    for(var i=0;i<json.length;i++){
      return Cart(name: json[i]['package'] ?? '', price: json[i]['total_price'] ?? '');
    }
  }
  return Cart(name: '', price: '');
  }
}

class CartPage extends StatefulWidget {
  const CartPage({Key? key});

  @override
  State<CartPage> createState() => CartPageState();
}

class CartPageState extends State<CartPage> {

  late Future<Cart> fetchCartData;
  final _razorPay = Razorpay();

  String _getReference() {
    var now = DateTime.now();
    return 'ch_${now.microsecondsSinceEpoch}';
  }

  void openCheckout() async {
    var options = {
      'key': 'rzp_test_InWjgP1w3i87qB',
      'amount': 2000,
      'name': 'RWA',
      'description': 'Fine T-Shirt',
      'prefill': {'contact': '8888888888', 'email': 'test@razorpay.com'},
      'external': {
        'wallets': ['paytm','phonepe','tez']
      },
    };
    _razorPay.open(options);
  }

  @override
  void initState() {
    super.initState();
    fetchCartData = fetchCartItems();
  }

  @override
  void dispose() {
    super.dispose();
    _razorPay?.clear();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
            appBar: AppBar(
                title: const Text("RWA Cart"),
                backgroundColor: Theme.of(context).colorScheme.inversePrimary,
                automaticallyImplyLeading: false,
            ),
            body: Center(
                child: FutureBuilder<Cart>(
                    future: fetchCartData,
                    builder: (context, snapshot) {
                        if(snapshot.hasData){
                            return Column(
                                mainAxisAlignment: MainAxisAlignment.center,
                                children: [
                                    Row(
                                        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                                        children: [
                                            Column(
                                                mainAxisAlignment: MainAxisAlignment.center,
                                                children: [
                                                    Text('Name:            ', style: TextStyle(fontSize: 16))]
                                                ),
                                            Column(
                                                mainAxisAlignment: MainAxisAlignment.center,
                                                children: [
                                                    Text(snapshot.data?.name?.toString() ?? "No data available", style: TextStyle(fontSize: 16))
                                                ]
                                            )
                                        ]
                                    ),
                                    Text(''),
                                    Row(
                                        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                                        children: [
                                            Column(
                                                mainAxisAlignment: MainAxisAlignment.center,
                                                children: [
                                                    Text('Price (in Rs.): ', style: TextStyle(fontSize: 16))
                                                ]
                                            ),
                                            Column(
                                                mainAxisAlignment: MainAxisAlignment.center,
                                                children: [
                                                    Text(snapshot.data?.price?.toString() ?? "0", style: TextStyle(fontSize: 16))
                                                ]
                                            )
                                        ]
                                    ),
                                    ElevatedButton(
                                        child: Text('Purchase'),
                                        onPressed: openCheckout
                                    )
                                ]
                            );
                        } else if (snapshot.hasError) {
                            return Text(snapshot.error?.toString() ?? "Unknown error", style: TextStyle(fontSize: 16));
                        }

                        return const CircularProgressIndicator();
                    }
                )
            )
    );
}
}

Please help.

Flutter Version :

Steps To Reproduce

Write the dependencies in pubspec.yaml
Design the cart screen using the cart screen code.
Inspect the browser window
Run the code and click on purchase button.

I get the following error.

errors.dart:294 Uncaught (in promise) Error: Unsupported operation: Platform._operatingSystem
    at Object.throw_ [as throw] (errors.dart:294:49)
    at _Platform._operatingSystem (io_patch.dart:244:5)
    at get operatingSystem [as operatingSystem] (platform_impl.dart:56:40)
    at get operatingSystem (platform.dart:83:44)
    at desc.get [as operatingSystem] (operations.dart:1220:8)
    at get isAndroid (platform.dart:156:50)
    at desc.get [as isAndroid] (operations.dart:1220:8)
    at razorpay_flutter.Razorpay.new.open (razorpay_flutter.dart:48:17)
    at open.next (<anonymous>)
    at runBody (async_patch.dart:84:54)
    at Object._async [as async] (async_patch.dart:127:5)
    at razorpay_flutter.Razorpay.new.open (razorpay_flutter.dart:35:12)
    at cart_screen.CartPageState.new.openCheckout (cart_screen.dart:76:15)
    at openCheckout.next (<anonymous>)
    at runBody (async_patch.dart:84:54)
    at Object._async [as async] (async_patch.dart:127:5)
    at cart_screen.CartPageState.new.openCheckout (cart_screen.dart:65:20)
    at ink_well._InkResponseState.new.handleTap (ink_well.dart:1154:21)
    at tap.TapGestureRecognizer.new.invokeCallback (recognizer.dart:275:24)
    at tap.TapGestureRecognizer.new.handleTapUp (tap.dart:654:11)
    at [_checkUp] (tap.dart:311:5)
    at tap.TapGestureRecognizer.new.handlePrimaryPointer (tap.dart:244:7)
    at tap.TapGestureRecognizer.new.handleEvent (recognizer.dart:630:9)
    at [_dispatch] (pointer_router.dart:98:12)
    at pointer_router.dart:143:9
    at LinkedMap.new.forEach (linked_hash_map.dart:21:13)
    at [_dispatchEventToRoutes] (pointer_router.dart:141:17)
    at pointer_router.PointerRouter.new.route (pointer_router.dart:127:7)
    at binding$5.WidgetsFlutterBinding.new.handleEvent (binding.dart:488:19)
    at binding$5.WidgetsFlutterBinding.new.dispatchEvent (binding.dart:468:14)
    at binding$5.WidgetsFlutterBinding.new.dispatchEvent (binding.dart:333:11)
    at [_handlePointerEventImmediately] (binding.dart:413:7)
    at binding$5.WidgetsFlutterBinding.new.handlePointerEvent (binding.dart:376:5)
    at [_flushPointerEventQueue] (binding.dart:323:7)
    at [_handlePointerDataPacket] (binding.dart:292:9)
    at Object.invoke1 (platform_dispatcher.dart:1319:13)
    at _engine.EnginePlatformDispatcher.new.invokeOnPointerDataPacket (platform_dispatcher.dart:303:5)
    at [_onPointerData] (pointer_binding.dart:168:39)
    at pointer_binding.dart:791:20
    at pointer_binding.dart:720:14
    at loggedHandler (pointer_binding.dart:317:16)
    at Object._checkAndCall (operations.dart:574:37)
    at Object.dcall (operations.dart:579:39)
    at ret (js_allow_interop_patch.dart:17:11)

razorpay / razorpay-flutter

Unsupported operation: Platform._operatingSystem #340

Flutter Version :

Steps To Reproduce