Trouble with WebSockets in Flutter - flutter

Question

I am having some trouble implementing WebSockets in my flutter application.
Here is code my code:
void connectToWebSocket() {
print("trying to connect to websocket");
final Future futureChannel = establishConnection();
futureChannel.then((future) {
print("Connection established, registering interest now...");
channel = future;
webSocketConnected = true;
channel.sink.add({
"action": "saveConnection",
"UserName": "rakshak#gmail.com",
"DeviceId": "1d0032000947363339343638"
});
}).catchError((error) {
channel = null;
webSocketConnected = false;
webSocketConnectionError = error.toString();
print("Connection failed \n $webSocketConnectionError");
});
}
Future<IOWebSocketChannel> establishConnection() async {
final IOWebSocketChannel channel = IOWebSocketChannel.connect(
'wss://1j839fy6t3.execute-api.us-east-1.amazonaws.com/Dev');
return channel;
}
Nothing seems to happen when this code runs. I can see the print messages saying "trying to connect to WebSocket" and "Connection established, registering interest now..." on the console.
The WebSocket is implemented using AWS API Gateway and I can see in the logs that the Flutter app has not connected to the WebSocket.
I have tested the WebSocket using wscat command-line tool and I know that it works.
I am not seeing any error in the console.
Let me know if you would like to see any more of my code.

Answer 1

Turns out you channel.sink.add accepts a string and not a Map.
Replace
channel.sink.add({
"action": "saveConnection",
"UserName": "rakshak#gmail.com",
"DeviceId": "1d0032000947363339343638"
});
With
channel.sink.add('{
"action": "saveConnection",
"UserName": "rakshak#gmail.com",
"DeviceId": "1d0032000947363339343638"
}');
and it should work.

Answer 2

I don't understand what you want. But If you want websocket, you can refer below one.
Add Dart Pub
adhara_socket_io
Add class
class SignalServer {
static SignalServer _instatnce;
factory SignalServer() => _instatnce ?? new SignalServer._();
SignalServer._();
SocketIO socketIO;
int State = 0;
void ConnectServer() async {
this.socketIO = await SocketIOManager().createInstance("http://192.168.50.65:8081");
socketIO.onConnect((data) {
print("Signal server connected");
State = 1;
});
socketIO.onDisconnect((_) {
print("Signal Disconnected");
State = 0;
});
socketIO.connect();
}
}
For Instance(main.dart)
static SignalServer signalServer;
....
signalServer = new SignalServer();
signalServer.ConnectServer();
For use
In any widget
void initState() {
super.initState();
setSocketEvent();
}
void setSocketEvent() async{
await MyApp.signalServer.socketIO.on("room-ready", (data) {
//enter your code
});
await MyApp.signalServer.socketIO.on("on-message", (data) {
//enter your code
});
...
}
I hope it will help you.