Subscription with Phoenix in Flutter. How to get response from subscription

Question

What happened?

When I click on the button confirm, a method _doSend is called. This method call a HTTP POST request (the method sends a transaction to a blockchain and waits the result). HTTP POST response contains the status of the response (“pending”) and we get the “ok” status with the Subscription with Phoenix. So when I receive “ok”, I want to display the status. With the following code, my subcription is ok:

logs from HTTP request and response:

[log] sendTx: requestHttp.body={"version":1,"address":"0…c62d75a51d8c53187fc1f3f50ed885666c60b17941a3f0e"}
[log] sendTx: responseHttp.body={"status":"pending","tra…1794E1A1D69C4184B3D3D58C823E778549F139361F1C0ED"}

The status is pending => ok

logs from network

The status is ok => ok

BUT I don't find how to get the status from subscription ....

My Code:

/// SPDX-License-Identifier: AGPL-3.0-or-later

// Dart imports:
import 'dart:async';

// Flutter imports:
import 'package:aewallet/ui/views/transactions/phoenix_link.dart';
import 'package:flutter/material.dart';

// Package imports:
import 'package:aeuniverse/ui/widgets/components/buttons.dart';
import 'package:core/localization.dart';
import 'package:core/service/app_service.dart';
import 'package:core/util/get_it_instance.dart';
import 'package:core_ui/ui/util/dimens.dart';

// Project imports:
import 'package:graphql_flutter/graphql_flutter.dart';

class TransferConfirmSheet extends StatefulWidget {
  const TransferConfirmSheet({super.key});

  @override
  State<TransferConfirmSheet> createState() => _TransferConfirmSheetState();
}

class _TransferConfirmSheetState extends State<TransferConfirmSheet> {
  PhoenixLink? link;
  ValueNotifier<GraphQLClient>? client;

  // your subscription query
  final subscriptionDocument = gql(
      """subscription { transactionConfirmed(address: "0000D2690135438EF7842075DCEB62E42F46614B6E3478FCE01A943EC7E699AC74C3") { nbConfirmations } }""");

  Future<void> initGraphQLChannel() async {
    // my absinthe plug api location
    final HttpLink phoenixHttpLink = HttpLink(
      'http://localhost:4000/socket/websocket',
    );

    // my websocket location
    String websocketUri = "ws://localhost:4000/socket/websocket";

    // creation of phoenixChannel for use in PhoenixLink
    final phoenixChannel =
        await PhoenixLink.createChannel(websocketUri: websocketUri);

    final phoenixLink = PhoenixLink(
      channel: phoenixChannel,
    );
    var _link = Link.split(
        (request) => request.isSubscription, phoenixLink, phoenixHttpLink);

    client = ValueNotifier(
      GraphQLClient(
        link: _link,
        cache: GraphQLCache(),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return SafeArea(
      minimum:
          EdgeInsets.only(bottom: MediaQuery.of(context).size.height * 0.035),
      child: Column(
        children: <Widget>[
          Expanded(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.start,
              children: <Widget>[
                client == null
                    ? const SizedBox()
                    : Center(
                        child: GraphQLProvider(
                          client: client,
                          child: Subscription(
                              options: SubscriptionOptions(
                                document: subscriptionDocument,
                              ),
                              builder: (result) {
                                if (result.hasException) {
                                  return Text(result.exception.toString());
                                }
                                if (result.isLoading) {
                                  return const Center(
                                    child: CircularProgressIndicator(),
                                  );
                                }
                                return ResultAccumulator.appendUniqueEntries(
                                    latest: result.data,
                                    builder: (context, {results}) =>
                                        Text(result.data.toString()));
                              }),
                        ),
                      ),
              ],
            ),
          ),
          Container(
            margin: const EdgeInsets.only(top: 10.0),
            child: Column(
              children: <Widget>[
                Row(
                  children: <Widget>[
                    AppButton.buildAppButton(
                      const Key('confirm'),
                      context,
                      AppButtonType.primary,
                      AppLocalization.of(context)!.confirm,
                      Dimens.buttonTopDimens,
                      onPressed: () async {
                        _doSend();
                      },
                    ),
                  ],
                ),
                Row(
                  children: <Widget>[
                    AppButton.buildAppButton(
                        const Key('cancel'),
                        context,
                        AppButtonType.primary,
                        AppLocalization.of(context)!.cancel,
                        Dimens.buttonBottomDimens, onPressed: () {
                      Navigator.of(context).pop();
                    }),
                  ],
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Future<void> _doSend() async {
    await initGraphQLChannel();
    await sl.get<AppService>().send();
  }
}