Socket got disconnected after a few second

[chounry]

I am be able to publish and retrieve data of a channel. But the connection always got disconnected after a few seconds from where i call `Socket.connection.

E/flutter (16915): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: FormatException: Unexpected end of input (at character 1)
E/flutter (16915): 
E/flutter (16915): ^
E/flutter (16915): 
E/flutter (16915): #0      _ChunkedJsonParser.fail (dart:convert-patch/convert_patch.dart:1394:5)
E/flutter (16915): # 1      _ChunkedJsonParser.close (dart:convert-patch/convert_patch.dart:512:7)
E/flutter (16915): # 2      _parseJson (dart:convert-patch/convert_patch.dart:32:10)
E/flutter (16915): # 3      JsonDecoder.convert (dart:convert/json.dart:505:36)
E/flutter (16915): # 4      JsonCodec.decode (dart:convert/json.dart:153:41)
E/flutter (16915): # 5      jsonDecode (dart:convert/json.dart:96:10)
E/flutter (16915): # 6      Socket.handleMessage (package:socketcluster_client/src/socket.dart:135:17)
E/flutter (16915): # 7      _rootRunUnary (dart:async/zone.dart:1192:38)
E/flutter (16915): # 8      _CustomZone.runUnary (dart:async/zone.dart:1085:19)
E/flutter (16915): # 9      _CustomZone.runUnaryGuarded (dart:async/zone.dart:987:7)
E/flutter (16915): # 10     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
E/flutter (16915): # 11     _BufferingStreamSubscription._add (dart:async/stream_impl.dart:266:7)
E/flutter (16915): # 12     _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:779:19)
E/flutter (16915): # 13     _StreamController._add (dart:async/stream_controller.dart:655:7)
E/flutter (16915): #14     _StreamController.add (dart:async/stream_controller.dart:597:5)
E/flutter (16915): #15     new _WebSocketImpl._fromSocket.<anonymous closure> (dart:_http/websocket_impl.dart:1146:21)
E/flutter (16915): #16     _rootRunUnary (dart:async/zone.dart:1192:38)
E/flutter (16915): #17     _CustomZone.runUnary (dart:async/zone.dart:1085:19)
E/flutter (16915): #18     _CustomZone.runUnaryGuarded (dart:async/zone.dart:987:7)
E/flutter (16915): #19     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
E/flutter (16915): #20     _BufferingStreamSubscription._add (dart:async/stream_impl.dart:266:7)
E/flutter (16915): #21     _SinkTransformerStreamSubscription._add (dart:async/stream_transformers.dart:70:11)
E/flutter (16915): #22     _EventSinkWrapper.add (dart:async/stream_transformers.dart:17:11)
E/flutter (16915): #23     _WebSocketProtocolTransformer._messageFrameEnd (dart:_http/websocket_impl.dart:338:22)
E/flutter (16915): #24     _WebSocketProtocolTransformer._startPayload (dart:_http/websocket_impl.dart:322:9)
E/flutter (16915): #25     _WebSocketProtocolTransformer._lengthDone (dart:_http/websocket_impl.dart:294:7)
E/flutter (16915): #26     _WebSocketProtocolTransformer.add (dart:_http/websocket_impl.dart:197:13)
E/flutter (16915): #27     _SinkTransformerStreamSubscription._handleData (dart:async/stream_transformers.dart:122:24)
E/flutter (16915): #28     _rootRunUnary (dart:async/zone.dart:1192:38)
E/flutter (16915): #29     _CustomZone.runUnary (dart:async/zone.dart:1085:19)
E/flutter (16915): #30     _CustomZone.runUnaryGuarded (dart:async/zone.dart:987:7)
E/flutter (16915): #31     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
E/flutter (16915): #32     _BufferingStreamSubscription._add (dart:async/stream_impl.dart:266:7)
E/flutter (16915): #33     _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:779:19)
E/flutter (16915): #34     _StreamController._add (dart:async/stream_controller.dart:655:7)
E/flutter (16915): #35     _StreamController.add (dart:async/stream_controller.dart:597:5)
E/flutter (16915): #36     _Socket._onData (dart:io-patch/socket_patch.dart:1982:41)
E/flutter (16915): #37     _rootRunUnary (dart:async/zone.dart:1196:13)
E/flutter (16915): #38     _CustomZone.runUnary (dart:async/zone.dart:1085:19)
E/flutter (16915): #39     _CustomZone.runUnaryGuarded (dart:async/zone.dart:987:7)
E/flutter (16915): #40     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
E/flutter (16915): #41     _BufferingStreamSubscription._add (dart:async/stream_impl.dart:266:7)
E/flutter (16915): #42     _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:779:19)
E/flutter (16915): #43     _StreamController._add (dart:async/stream_controller.dart:655:7)
E/flutter (16915): #44     _StreamController.add (dart:async/stream_controller.dart:597:5)
E/flutter (16915): #45     new _RawSocket.<anonymous closure> (dart:io-patch/socket_patch.dart:1527:33)
E/flutter (16915): #46     _NativeSocket.issueReadEvent.issue (dart:io-patch/socket_patch.dart:1019:14)
E/flutter (16915): #47     _microtaskLoop (dart:async/schedule_microtask.dart:43:21)
E/flutter (16915): #48     _startMicrotaskLoop (dart:async/schedule_microtask.dart:52:5)

I/flutter (16915): onDisconnected: socket Instance of 'Socket'

Then the server cannot retrieve data anymore.

[chounry]

I just found out. It was because of the client module does not ping back to the server. I had to modified the package.

[egiadtya]

@chounry I got same issue, any workaround you did to fix this?

[chounry]

Hi, @egiadtya
Yes, I cloned the package and modified this function:

socketcluster_client/lib/src/socket.dart

Lines 123 to 193 in fcdc48f

	void handleMessage([dynamic messageEvent]) {
	String? message;
	if (globalSocketPlatform is IoSocketPlatform) {
	message = messageEvent;
	} else {
	message = messageEvent.data;
	}
	if (message == "#1") {
	sendOrAdd('#2');
	} else {
	// print('Message received: $message');
	var map = jsonDecode(message!);
	var data = map['data'];
	int? rid = map['rid'];
	int? cid = map['cid'];
	String? event = map['event'];
	// print('Event: $event, rid: $rid, cid: $cid, data: $data');
	switch (Parser.parse(data, rid, cid, event)) {
	case ParseResult.ISAUTHENTICATED:
	// print('IS authenticated got called');
	id = data['id'] as String?;
	bool? auth = data['isAuthenticated'] as bool?;
	if (listener != null) {
	listener!.onAuthentication(this, auth);
	}
	subscribeChannels();
	break;
	case ParseResult.PUBLISH:
	handlePublish(data['channel'] as String?, data['data']);
	// print('Publish got called');
	break;
	case ParseResult.REMOVETOKEN:
	authToken = null;
	// print('Removetoken got called');
	break;
	case ParseResult.SETTOKEN:
	if (listener != null) {
	listener!.onSetAuthToken(data['token'] as String?, this);
	}
	// print('Set token got called');
	break;
	case ParseResult.EVENT:
	if (hasEventAck(event)) {
	handleEmitAck(event, data, ack(cid));
	} else {
	handleEmit(event, data);
	}
	break;
	case ParseResult.ACKRECEIVE:
	// print('Ack receive got called');
	if (_acks.containsKey(rid)) {
	var mapObj = _acks[rid!];
	_acks.remove(rid);
	if (mapObj != null) {
	AckCall fn = mapObj[1];
	if (fn != null) {
	fn(mapObj[0] as String, map['error'], map['data']);
	} else {
	// print('Ack function is null');
	}
	}
	}
	break;
	default:
	throw new RangeError('Unknown ParseResult');
	}
	}
	}

From this :

if (message == "#1") {
  sendOrAdd('#2');
} else {
   ....
}

To this:

if (message == "#1") {
    sendOrAdd('#2');
} else if(message.isNotEmpty){
   ...
}else {
   sendOrAdd('');
}