The library cannot switch between long polling and websocket

[lopezchr]

The library only works when you use transporting over websocket. By default the library send the connection request over http (long polling) and you can see it on the access log of the server but never switch to websocket.

We are using socket io version 2.0.4 on our server.

172.31.3.14 - - [20/Aug/2019:08:12:06 -0500] "GET /socket.io/?EIO=3&transport=polling&t=Mol9v3G&sid=c40FSVz-gs98xm1iAALE HTTP/1.1" 200 3 "http://stagingiris.1doc3.com/" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.100 Safari/537.36" "201.217.201.157"

[jumperchen]

It works to me.
socket.io 2.0.4 version NodeJS

Server code

const io = require('socket.io')(3000);
io.origins('*:*');
io.on('connection', function (socket) {
    socket.on('msg', (data) => {
        console.log('data from default => ' + data);
      socket.emit('fromServer', data);
    });
});

Socket.io-client-dart

import 'package:socket_io_client/socket_io_client.dart' as IO;

main() {
  IO.Socket socket = IO.io('http://localhost:3000');
  socket.on('connect', (_) {
    print('connect');
    socket.emit('msg', 'init');
    int count = 0;
    new Timer.periodic(const Duration(seconds: 1), (Timer countDownTimer) {
      socket.emit('msg', count++);
    });
  });
  socket.on('fromServer', (_) => print(_));
}

[lopezchr]

We are working on a Flutter app... maybe it is not supported??

[jumperchen]

Flutter? it's not browser based, you can only use dart:io library with websocket transports, which is already mentioned here. https://github.com/rikulo/socket.io-client-dart/blob/master/test/io_client.dart