knaeckekami / gql_phoenix_link

A gql Link for communicating over Phoenix Channels

Hi there 👋

gql_phoenix_link's Issues

Heartbeat

Hello

when i use PhoenixLink with SubscriptionChannel class, i try to close subscription but i see after the closing, some logs with

Do you know how to close completely the connection please

Thx

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

// Package imports:
import 'package:graphql_flutter/graphql_flutter.dart';
import 'package:phoenix_socket/phoenix_socket.dart';

// Project imports:
import 'package:core/util/confirmations/phoenix_link.dart';

class SubscriptionChannel {
  PhoenixSocket? socket;
  PhoenixChannel? channel;
  GraphQLClient? client;

  final StreamController<Map> _onMessageController = StreamController<Map>();
  Stream<Map> get onMessage => _onMessageController.stream;

  Future<void> connect(
      String phoenixHttpLinkEndpoint, String websocketUriEndpoint) async {
    final HttpLink phoenixHttpLink = HttpLink(
      phoenixHttpLinkEndpoint,
    );

    channel =
        await PhoenixLink.createChannel(websocketUri: websocketUriEndpoint);
    final phoenixLink = PhoenixLink(
      channel: channel!,
    );

    var link = Link.split(
        (request) => request.isSubscription, phoenixLink, phoenixHttpLink);
    client = GraphQLClient(
      link: link,
      cache: GraphQLCache(),
    );
  }

  void addSubscriptionTransactionConfirmed(
      String address, Function(QueryResult) function) {
    final subscriptionDocument = gql(
      'subscription { transactionConfirmed(address: "$address") { nbConfirmations } }',
    );

    Stream<QueryResult> subscription = client!.subscribe(
      SubscriptionOptions(document: subscriptionDocument),
    );
    subscription.listen(function);
  }

  Future<Message> onPushReply(Push push) async {
    final Completer<Message> completer = Completer<Message>();
    final Message result = await channel!.onPushReply(push.replyEvent);
    completer.complete(result);
    return completer.future;
  }

  void close() {
    _onMessageController.close();
    if (socket != null) {
      socket!.close();
    }
    if (channel != null) {
      channel!.close();
    }
  }
}

Example usage

For people looking for full working example
call initGraphQLChannel() from initstate

void initGraphQLChannel() async {
    // your absinthe plug api location
    final HttpLink phoenixHttpLink = HttpLink(
      'http://192.168.1.23:4000/api',
    );

    // your websocket location
    String websocketUri = "ws://192.168.1.23:4000/socket/websocket";

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

    // creation of PhoenixLink
    final phoenixLink = PhoenixLink(
      channel: phoenixChannel,
    );

    // Split like in flutter graphql documentation between websocket and http requests
    var _link = Link.split(
        (request) => request.isSubscription, phoenixLink, phoenixHttpLink);
    final GraphQLClient client = GraphQLClient(
      link: _link,
      cache: GraphQLCache(),
    );

    // your subscription query
    final subscriptionDocument = gql(
      r'''
    subscription{
  postAdded{
    id
    name
    description
  }
}
  ''',
    );

    // subscribe and listen
    Stream<QueryResult> subscription = client.subscribe(
      SubscriptionOptions(document: subscriptionDocument),
    );
    subscription.listen(reactToPostCreated);
  }

  void reactToPostCreated(QueryResult event) {
    print("Received event =>");
    print(event);
  }

  // example event received structure
  // Received event =>
  // I/flutter (15033): QueryResult(source: QueryResultSource.network, data: {postAdded: {__typename: Post, id: 32, name: graphqllink post, description: something something}}, context: Context({ResponseExtensions: Instance of 'ResponseExtensions'}), exception: null, timestamp: 2021-09-02 20:15:40.365330)