Can we use socket socket.io-client as standalone on browser without having socket.io in server side

[vicky-allen]

Hi Team,
We are implementing chat application where our backend is using gorilla golang
In UI can we use socket.io-client as standalone or do we need socket.io on server side as well
I am able to create a connection on UI but not able to send message
Events like io!.on('connection',) not working
socket.emit('request', /* … */); // not working
socket.on('reply', (event) => {
console.log("socket reply", event)
});
Above events are not working
What i suspect is socket-io is event based and we need socket io in backend also to receive these events in client

import { io } from "socket.io-client";
`
this.socket = io('url', {
path: '/',
transports: ["websocket"],
autoConnect: true,
// reconnectionDelayMax: 10000,
query: {

    }
  })
 
  io!.on('connection', socket => {
    this.setupKeepAlive()
    // socket.emit('request', /* … */); // emit an event to the socket
    // io.emit('broadcast', /* … */); // emit an event to all connected sockets
    const testObject = {
      "request": {
        "type": "TEST",
        "sub_type": "TEST1",
        "data": {}
      }
    };
    this.socket!.emit('request',JSON.stringify(testObject));
    socket.on('reply', (event) => { 
      console.log("socket reply", event)
     }); // listen to the event
  });

`

[vicky-allen]

https://stackoverflow.com/questions/19506735/client-side-socket-io-without-a-node-js-server this stackoverflow question suggests that server should also have used shocket io protocol my question how can we test that server is using socket io protocol

Also can we use https://github.com/socketio/engine.io-client/ as stand alone

[darrachequesne]

Hi! A Socket.IO server is indeed needed. Several implementations are available:

Language	Source
JavaScript (Node.js)	https://github.com/socketio/socket.io
JavaScript (Deno)	https://github.com/socketio/socket.io-deno
Java	https://github.com/mrniko/netty-socketio
Java	https://github.com/trinopoty/socket.io-server-java
Python	https://github.com/miguelgrinberg/python-socketio
Golang	https://github.com/googollee/go-socket.io
Rust	https://github.com/Totodore/socketioxide

Reference: https://socket.io/docs/v4/#server-implementations

The Socket.IO protocol is described there: https://socket.io/docs/v4/socket-io-protocol/