CODEWITHSUNDEEP
node.jsexpresssocket.io
Farid Ghaderi
Farid Ghaderi

Reputation: 134

what is the best way to use socket.io with expressjs app?

I want to write a real-time chat application with socket.io and because my server and app file are separate, I kind of have no clue that how should I structure it to use socket.io instance in other parts of my app. This is my app.js file.

const express = require("express");
const pug = require("pug");
const app = express();

module.exports = app;

and this is my server.js file

const app = require("./app");
const mongoose = require("mongoose");
mongoose
  .connect(`mongodb://localhost:27017/${process.env.DATABASE}`)
  .then(() => {
    app.listen(process.env.PORT);
  })
  .catch((err) => {
    console.error(`connection failed: ${err}`);
  });

what is the best way to create an instance of socket.io and start it's connection for use in other parts of app?

Upvotes: 0

Views: 328

Answers (1)

Zunnurain Badar
Zunnurain Badar

Reputation: 1042

You can use http with express app and then connect sockets through that http connection and you can listen and emit the topics inside the io.on('connection')

const app = require("./app");
const mongoose = require("mongoose");
const http = require('http').Server(app);
const io = require('socket.io')(http);
mongoose
  .connect(`mongodb://localhost:27017/${process.env.DATABASE}`)
  .then(() => {
    app.listen(process.env.PORT);
    io.on('connection', socket => {
      console.log('socket connected',socket);
    });
  })
  .catch((err) => {
    console.error(`connection failed: ${err}`);
  });

I will prefer this second way:

App.js

const express = require("express");
const pug = require("pug");
const app = express();
module.exports = app;

Server.js

const app = require("./app");
const realtime = require("./realtime");
const mongoose = require("mongoose");
const server = require("http").Server(app);

mongoose
  .connect(`mongodb://localhost:27017/${process.env.DATABASE}`)
  .then(() => {
    app.listen(process.env.PORT);
    require("./realtime.js")(server);

  })
  .catch((err) => {
    console.error(`connection failed: ${err}`);
  });

Realtime.js

module.exports = (app) => {
    const io = require("socket.io")(app);
    io.on("connection", (socket) => {
      console.log("Socket connected")
    })
};

Upvotes: 1

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