I am trying to socket.io to react native. It works perfectly fine on iOS device but doesn't work on android. I was doing some research and found out you need to usesCleartextTraffic="true".

I did that and its still not working. Below is my code. Any help would be really appreciated.

server code

const app = express();
const httpServer = createServer(app);
const io = new Server(httpServer)

io.on("connection", (socket) => {
    socket.on("hello",function (){
        io.emit("hello", "worldd");
    })
});

httpServer.listen(3000);

Client Side

useEffect(()=> {


    try {
      const socket = io('http://localhost:3000');


      socket.on("hello", (param) => {
        console.log(socket.id); // x8WIv7-mJelg7on_ALbx
        console.log(param);
      });


    } catch (e) {

      console.log(e)

    }


  });

CodePudding user response：

I think first you need to change the way you are setting up you server, change it to this instead as suggested by the documentation

const app = express();
const http = require('http');
const server = http.createServer(app);
const io = new Server(server);

The calling socket emit and on seems to be correct so try this and let me know if it works. you can also check full documentation here https://socket.io/get-started/chat

CodePudding user response：

As @Mustafa mentioned, createServer method comes from http module. So:

Server side:

const { Server } = require("socket.io"); 
const http = require('http'); const server = http.createServer(app); 
const io = new Server();

io.on("connection", (socket) => {
  socket.on("hello", (param) => {
    io.sockets.emit("hello", param);
  });
});

io.attach(server); // Attach socket.io to the server
server.listen(3000);

Client side:

1. Listen to "connect" event to make sure that the connection was successful.
2. Emit "hello" event for the server to respond back to this event.

So:

import { io } from "socket.io-client";

const socket = io('http://localhost:3000');
socket.on("hello", (param) => {
    console.log(param);
});

socket.on("connect", () => {
  console.log("Successfully connected!"); 
  socket.emit("hello", "world");
});