socket_io_client for socket connect triggering multiple times

user_14463340 0
Viewed 1590

I am using the socket_io_client library for the socket connection in the flutter app. for example

@override
  void initState() {
    super.initState();
      connectToSocket();
    });

 connectToSocket() {
    Socket socket = io('http://xyxz', <String, dynamic>{
        'query': {"sdsxyz"} // optional
      });
    socket.connect();
     }

calling this method at initState. for socket connect. but socket connection trigger(socket connected socket disconnected)multiple times at the server end.

server-side code.

const app = require('express')()
const http = require('http').createServer(app)
app.get('/', (req, res) => {
    res.send("Node Server is running. Yay!!")
})
//Socket Logic
const socketio = require('socket.io')(http)
socketio.on("connection", (userSocket) => {
    console.log("Socket connected", userSocket.id)
    userSocket.on("send_message", (data) => {
        userSocket.broadcast.emit("receive_message", data)
    })
})

I want that socket connection should be called once for the normal flow of data.

socket.io dart flutter sockets websocket
3 Answers

Where are you calling the socket.connect() is the important part here. If our socket is connecting several times, maybe your method is triggered on a widget that is being re-renderized by state changes.

Try to move it to a new function called at the end of initState:

@override
void initState() {
 super.initState();

 this.connectToSocket();
}

void connectToSocket() {
  ...
}

EDIT: You also need to remove your socket on dispose, and use a reference to your socket:

Socket socket;

@override
  void initState() {
    super.initState();
      connectToSocket();
    });

 connectToSocket() {
    if(socket){ return; }
    socket = io('http://xyxz', <String, dynamic>{
        'query': {"sdsxyz"} // optional
      });
    socket.connect();
     }

 @override 
 void dispose() {
if(socket) {
  socket.disconnect();
}
super.dispose();

}

user_40775590

for Flutter: use socket_io_client
use property 'transports': ['webscoket']
link:https://pub.dev/packages/socket_io_client.
Why polling is not supported
'transports': ['polling'] does not support in Flutter, by default this library was designed for dart web, but dart web is not popular than Flutter; the polling mechanism is ported from Socket.io JS, which is using Ajax way to implement, but it's not allowed in dart:io library.

user_144633400

solved by adding enableForceNewConnection()

 socket = io(
        'your socket url,
        OptionBuilder()
            .setTransports(['websocket'])

            //add this line
            .enableForceNewConnection() // necessary because otherwise it would reuse old connection
            .disableAutoConnect()
            .build());
user_134000010
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