GraphQl subscription throwing exception when subscribing with Apollo server flutter

Question

GraphQl subscription throwing exception "web socket connect failed" when subscribing with Apollo server. Subscription is working fine with graphQl explorer but failing when implemented in flutter

Code and exceptions are attached below.

********** Code ***********

final _wsLink = WebSocketLink(    
  ‘***************’,    
  config: SocketClientConfig(
    autoReconnect: true,
    inactivityTimeout: Duration(hours: 1),
    // delayBetweenReconnectionAttempts: Duration(seconds: 1),
  ),  
); 

final Link _link = Link.split((request) => request.isSubscription, _wsLink, httpLink);
     
client = GraphQLClient(     
  cache: GraphQLCache(store: InMemoryStore()),
  link: _link,  
);

SubscriptionOptions options = SubscriptionOptions(
  document: gql(query),
  variables: variables);

final result = client.subscribe(options);

result.listen((event) {
  print("Event fired ${event.data}");
  print("Event fired ${event.exception?.graphqlErrors.toString()}");
}).onError((e) {
  print("Received Error ! ${e.toString()}");
});

return result;

************ Exception ***************

I/flutter ( 5204): Disconnected from websocket.

score 0 · Answer 1 · answered Mar 13 '23 at 18:55

I'm late but this works for me, if you have Apollo Server 4

final HttpLink httpLink = HttpLink(
    'http://192.168.43.29:4000/graphql', // my localhhost
  );
  
   final AuthLink authLink = AuthLink(
      getToken: () async => 'Bearer $token',
    );
    Link link = authLink.concat(httpLink);

    WebSocketLink websocketLink = WebSocketLink(
      'ws://192.168.43.29:4000/graphql/subscriptions', // my localhhost
      config: SocketClientConfig(
          autoReconnect: true,
          inactivityTimeout: const Duration(seconds: 30),
          initialPayload: {
            'token': token,
          },
          ),
      subProtocol: GraphQLProtocol.graphqlTransportWs, // This line is important, by default protocol is GraphQLProtocol.graphqlWs
    );

    if (websocketLink != null) {
      link =
          Link.split((request) => request.isSubscription, websocketLink, link);
    }

    graphqlClient = ValueNotifier(
      GraphQLClient(
        link: link,
        cache: GraphQLCache(store: HiveStore()),
      ),
    );

GraphQl subscription throwing exception when subscribing with Apollo server flutter

1 Answers1