SocketIO emit won't fire inside express route - node.js

The following works fine, I can get the http response on my client app BUT the socketio emit doesn't seem to work. I have no idea why it is not firing.
Here's my code (some parts removed):
app.js
var express = require('express');
var port = process.env.PORT || 3000;
var socketio = require('socket.io');
var app = express();
var server = require('http').Server(app);
var io = socketio(server);
var beacons = require('./routes/beacons')(io);
app.use('/beacons', beacons);
server.listen(port, () => {
console.log('Listening on port '+port);
});
io.on('connection', (socket) => {
socket.on('beacon:show', function(data) {
console.log('Show beacon: ' + data)
socket.broadcast.emit('beacon:draw', data)
})
});
module.exports = app;
beacons.js
var express = require('express');
var router = express.Router();
module.exports = function(io) {
router.get('/buy', function(req, res) {
io.emit('beacon:show', {data: someData}) // Not Firing
res.json({success: true})
})
return router
}

You need to wrap your io.emit() inside an io.on('connection', => {}).
At the moment, you are sending in just the io variable, but every single request and emission needs to be wrapped inside a connection event. Otherwise how does socket.io know who it's sending it to, or if there's even anyone to send it to?
This can only really be done inside beacons.js and the router.get('/buy') section, because having it the other way around (a route wrapped inside a connection) won't work.

Related

How do i start Socket.IO

I want to add socket.io on the index and it is like this i need to figure out how to do this with this code here and i want to emit the data when a route is called in another file how can i do this? you can see i tried down the code to put the socket io but i don't know can someone help please? also this is made in the backend like this is supposed to be an API and i'll not have a front-end and that's my problem i never used socket.io like this
// all the requires
require('./models/Service');
require('./models/Activities');
const express = require('express');
const app = express();
const mongoose = require('mongoose');
const bodyParser = require('body-parser');
const cors = require('cors');
const serviceRoutes = require('./routes/serviceRoutes');
const activityRoutes = require('./routes/activitiesRoutes');
const errorHandler = require('./helpers/Error-handler');
const logger = require('./config/winston');
const http = require('http').Server(app);
// all the app use
app.use(cors());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
app.use(serviceRoutes);
app.use(activityRoutes);
app.use(errorHandler);
// this calls for the users route to authenticate
app.use('/users', require('./Users/user.controller'));
// connection to database
mongoose.connection.on('connected', () => {
console.log('Connected to mongo instance');
});
mongoose.connection.on('error', err => {
console.error('Error connecting to mongo', err);
});
// server start up
const port = process.env.NODE_ENV === 'production' ? 80 : 4000;
http.listen(port, function() {
console.log('listening on ' + port);
try {
logger.info('Server and Database is initiated');
}
catch (error) {
logger.error(error);
}
});
// implementation of io
const io = require("socket.io")(http);
io.on('connection', function(socket) {
console.log('A user connected');
socket.on('disconnect', function () {
console.log('A user disconnected');
});
});
app.get('/', function(req, res) {
res.send(console.log('hey', io))
});
module.exports = io;
You can have the socket join a room on connection and attach io to the app object with app.set('io', io). This can then be accessed in controllers with req.app.get('io'), and you can emit to specific rooms.

Express server and socket.io not working in same port

Not working can't find any issue in code##
If I put any port number instead of server it's working but why didn't it's working with socket server anyone explain
I tried some solution but none of them work I want to run socket.io and express on same port number
const express = require('express');
const cors = require("cors");
const socketIO = require('socket.io');
const http = require('http');
const app = express();
const server = http.createServer(app);
const passport = require("passport");
const authRoute = require('./routes/auth');
const userRoute = require('./routes/user');
const PORT = process.env.PORT || 9000;
const db = require('./config/mongoose');
app.use(express.json());
app.use(cors());
app.use(passport.initialize());
require("./config/passport")(passport);
app.use(express.json());
app.use("/api/auth", authRoute);
app.use("/api/user", passport.authenticate('jwt', { session: false }),userRoute);
if(process.env.NODE_ENV === 'production')
{
app.use(express.static('client/build'))
}
Here is the issue if I switch server to any port number it's fine
const io = socketIO(server, {
cors: {
origin: '*',
}
});
let state = {};
io.on("connection", (socket) => {
const { id } = socket.client;
socket.on('disconnect', function () {
console.log('socket disconnected!');
});
socket.on('join_room', function (data) {
console.log('joining request rec.', data);
socket.join(data.room);
io.in(data.room).emit('user_joined', data);
});
socket.on('send_code', function (data) {
io.in(data.room).emit('receive_code', data);
});
});
app.listen(PORT, function (err) {
if(err){
console.log(err);
return;
}
console.log(`Server is up and running on port: ${PORT}`);
});
http.createServer(app) and app.listen() are not compatible as they both try to do the same thing. If you look at the source code for app.listen(), you will see this:
app.listen = function listen() {
var server = http.createServer(this);
return server.listen.apply(server, arguments);
};
So, it's creating a DIFFERENT server object. You end up with two and the first one never gets started so when you give it to socket.io, it never works.
Instead, remove this:
const server = http.createServer(app);
And, use this instead:
const server = app.listen(PORT, function (err) { ...});
This way, your server variable will contain the one and only server object that is actually running.
Alternatively, you could remove the app.listen() and then just add this in it's place:
server.listen(PORT, ...);
The general idea is that you want this pair:
const server = http.createServer(app);
server.listen(PORT, ...);
Or, just this:
const server = app.listen(PORT, ...);
You cannot use both. Either way, that server object will represent the server that is actually running and will work with socket.io.

Node.js how to use socket.io in express route

In one of my node.js script i am trying to use socket.io in express route. I found many similar questions and tried to implement the solution as suggested but nothing worked out. May be because of my lack of understanding of express routes. I followed below links,
How use socket.io in express routes with node.js
Use socket.io in expressjs routes instead of in main server.js file
This is my app.js
const express = require('express');
const app = express();
const server = require('http').createServer(app);
const io = require('socket.io').listen(server);
const PORT = 3000;
server.listen(PORT);
console.log('Server is running');
var api = require('./routes/api');
//app.use('/api', api);
app.use('/api', (req, res) => {
res.sendFile(__dirname + '/api.html');
});
app.get('/', (req, res) => {
res.send("this is home location");
});
And route file api.js in ./routes folder
var express = require('express');
var router = express.Router();
var fs = require("fs");
var bodyParser = require('body-parser');
const app = express();
const server = require('http').createServer(app);
const io = require('socket.io').listen(server);
console.log("inside api route");
router.get('/', function(req, res, next) {
console.log("api route called");
const connections = [];
var jsonobj = [{name:"john",score:345},{name:"paul",score:678}]
io.sockets.on('connection',(socket) => {
connections.push(socket);
console.log(' %s sockets is connected', connections.length); // this is not printing
socket.on('disconnect', () => {
connections.splice(connections.indexOf(socket), 1);
});
socket.emit('server message', jsonobj);
});
//res.send(jsonobj)
});
module.exports = router;
Socket.emit is not showing data on html page i am rendering on route use. My html code is,
//api.html
<!DOCTYPE html>
<html lang="en">
<body>
<div class="container">
<h1 class="jumbotron">
Node js Socket io with socket route example
</h1>
<div class="results">results</div>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.0.4/socket.io.js"></script>
<script>
jQuery(document).ready(function() {
var socket = io.connect();
var jsondata = "";
socket.on('server message', function(data){
console.log('got data from server',data)
jsondata = JSON.stringify(data);
//console.log('jsondata',jsondata)
$('.results').html(jsondata);
});
});
</script>
</body>
</html>
Please suggest what i am supposed to get route socket data in html page.
Thanks
Ok, let's try to understand why do you need to send data via the socket inside a route in the first place. Websockets are meant for sending data asynchronously without the client having to make a request. If the client is already making an HTTP request, then you can just send the data in the HTTP response.
Now having said there, there are clearly some use cases where you have to send data to some WebSocket channel based on the actions of some OTHER user's requests. If that is the case, there are multiple ways of doing this. One clean way would be to use an event-driven architecture.
Try something like this... find my comments inline below -
const express = require('express');
const router = express.Router();
const fs = require("fs");
const bodyParser = require('body-parser');
const app = express();
const server = require('http').createServer(app);
const io = require('socket.io').listen(server);
// move the socket connection outside of the route controller
// you must register the event listeners before anything else
const connections = [];
io.sockets.on('connection', (socket) => {
connections.push(socket);
console.log(' %s sockets is connected', connections.length); // this is not printing
socket.on('disconnect', () => {
connections.splice(connections.indexOf(socket), 1);
});
});
// Event emitter for sending and receving custom events
const EventEmitter = require('events').EventEmitter;
const myEmitter = new EventEmitter();
myEmitter.on('my-event', function (jsonobj) {
// do something here like broadcasting data to everyone
// or you can check the connection with some logic and
// only send to relevant user
connections.forEach(function(socket) {
socket.emit('server message', jsonobj);
});
});
router.get('/some-route', function (req, res, next) {
const jsonobj = [{ name: "john", score: 345 }, { name: "paul", score: 678 }]
// emit your custom event with custom data
myEmitter.emit('my-event', jsonobj);
// send the response to avoid connection timeout
res.send({ok: true});
});
module.exports = router;
At first glance, it looks like you are delcaring the URL prefix twice. Once in app.js and again in api.js.
Try localhost:port/api/api
If this is the case, change
router.get('/api', function(req, res, next){
to
router.get('/', function(req, res, next){
This will allow you to hit localhost:port/api and access your endpoint.
I am just starting to understand this myself, but I think where you are at is close.
In your app.js add to the end of the file:
const express = require('express');
const app = express();
const server = require('http').createServer(app);
const io = require('socket.io').listen(server);
const PORT = 3000;
server.listen(PORT);
console.log('Server is running');
var api = require('./routes/api');
//app.use('/api', api);
app.use('/api', (req, res) => {
res.sendFile(__dirname + '/api.html');
});
app.get('/', (req, res) => {
res.send("this is home location");
});
app.set("socketio", io); // <== this line
That stores the "io" variable in "socketio". Which you can grab in any of your other ".js" files.
var express = require('express');
var router = express.Router();
var fs = require("fs");
var bodyParser = require('body-parser');
const app = express();
const server = require('http').createServer(app);
//const io = require('socket.io').listen(server); // <== change this
const io = app.get("socketio"); // <== to this
console.log("inside api route");
router.get('/', function(req, res, next) {
console.log("api route called");
const connections = [];
var jsonobj = [{name:"john",score:345},{name:"paul",score:678}]
io.sockets.on('connection',(socket) => {
connections.push(socket);
console.log(' %s sockets is connected', connections.length); // this is not printing
socket.on('disconnect', () => {
connections.splice(connections.indexOf(socket), 1);
});
socket.emit('server message', jsonobj);
});
//res.send(jsonobj)
});
module.exports = router;
And you should do that with any other variables which are required in other ".js" files.
Also note that in your files, you are setting the variables up again. It is better to do the same as I've shown you with "io". The only variable in other files I setup is "app" itself.
Hope this helps...
You tried to create and start the servers from two different places in your single project, which is inconvenient. You just need some cleanup, that's all.
app.js
const express = require('express');
const app = express();
const server = require('http').createServer(app);
const io = require('socket.io').listen(server);
// Listen to sockets here instead of listening in routes/api.js
const connections = [];
var jsonobj = [{name:"john",score:345},{name:"paul",score:678}]
io.sockets.on('connection',(socket) => {
connections.push(socket);
console.log(' %s sockets is connected', connections.length); // this is not printing
socket.on('disconnect', () => {
connections.splice(connections.indexOf(socket), 1);
});
socket.emit('server message', jsonobj);
});
const PORT = 3000;
server.listen(PORT);
console.log('Server is running');
var api = require('./routes/api');
//app.use('/api', api);
app.use('/api', (req, res) => {
res.sendFile(__dirname + '/api.html');
});
app.get('/', (req, res) => {
res.send("this is home location");
});
routes/api.js
var express = require('express');
var router = express.Router();
var fs = require("fs");
var bodyParser = require('body-parser');
// Comment these out
// const app = express();
// const server = require('http').createServer(app);
// const io = require('socket.io').listen(server);
console.log("inside api route");
router.get('/', function(req, res, next) {
console.log("api route called");
// Comment these out
// const connections = [];
// var jsonobj = [{name:"john",score:345},{name:"paul",score:678}]
// io.sockets.on('connection',(socket) => {
// connections.push(socket);
// console.log(' %s sockets is connected', connections.length); // this is not printing
// socket.on('disconnect', () => {
// connections.splice(connections.indexOf(socket), 1);
// });
// socket.emit('server message', jsonobj);
// });
//res.send(jsonobj)
});
module.exports = router;
Leave your api.html as it is. Hope this helps.

404 error with express and express-ws

I'm having trouble trying to figure out why I'm getting this 404 error. I've gone through all the other questions on this site that cover 'express-ws' and i've modeled my code exactly how the solutions prescribed yet the websocket won't make a connection. I'm trying to create a websocket connection between my express server and react app. Below are previews of my code:
Express using express-ws (server.js):
var express = require('express');
var expressWs = require('express-ws');
var bodyParser = require('body-parser');
var cors = require('cors');
var nodemailer = require('nodemailer');
var email = require('./credentials');
var port = process.env.PORT || 3001;
var path = require('path');
// const WebSocket = require('ws');
// const http = require('http');
expressWs = expressWs(express());
let app = expressWs.app;
var server = require('http').createServer(app);
app.use(cors());
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
if (process.env.NODE_ENV === 'production') {
app.use(express.static('app/build'));
}
app.get('/', function(req, res){
console.log('server running!');
res.end();
});
app.ws('/ws', function(ws, req) {
console.log( 'socket running!' );
});
server.listen(port);
console.log('server started on port ' + port);
The GET route works fine but the ws route doesn't.
Call to express from React app:
componentDidMount() {
let ws = new WebSocket('ws://localhost:3001/ws');
ws.on( 'open', function open() {
console.log('app connected to websocket!');
} );
ws.on( 'message', function ( message ) {
console.log( message );
})
}
I've looked at all the following questions and don't understand why their solutions don't work for me:
Socket.IO 404 Error
express-ws connection problem
Node not working with express-ws
If anyone can let me know what's going on that would be great.
It seems your code does not follow express-ws's document. To use express-ws and make WebSocket endpoint, the code would be as:
var express = require('express');
var app = express();
var expressWs = require('express-ws')(app);
...
app.ws('/', function(ws, req) {
ws.on('message', function(msg) {
console.log(msg);
});
console.log('socket running');
});
app.listen(3000);
In the client side, ws object does not have field on. To listen WebSocket connection and message, you can use onopen and onmessage:
ws.onopen = function() {
console.log('app connected to websocket!');
};
ws.onmessage = function(message) {
console.log( message );
};
I had this exact problem and for me the solution was to change:
server.listen(port);
to:
app.listen(port);
I suspect what is going on is that express-ws is using the app listen function as its cue to start upgrading connections to ws and this won't happen if the server listen port occurs instead.

Nodejs include socket.io in router page

I have an express node app, and I'm trying to keep my code neat by not having all the socket.io stuff in app.js
I don't know the best way to go about this. Here is my initial thought which doesn't feel like the cleanest one
// app.js
var express = require('express')
, app = express()
, server = require('http').createServer(app)
, url = require('url')
, somePage = require('./routes/somePage.js')
, path = require('path');
app.configure(function(){...});
app.get('/', somePage.index);
and the route
// somePage.js
exports.index = function (req, res, server) {
io = require('socket.io').listern(server)
res.render('index',{title: 'Chat Room'})
io.sockets.on('connection', function(socket) {
...code...
}
}
I feel like I'm close but not quite there
I don't know if I'm reading that right but it looks like you are starting a socket server on every request for /, which I'm frankly a little surprised works at all.
This is how I'm separating out the socket.io code from app.js (using express 3.x which is a bit different than 2.x):
// app.js
var express = require('express');
var app = express();
var server_port = config.get('SERVER_PORT');
server = http.createServer(app).listen(server_port, function () {
var addr = server.address();
console.log('Express server listening on http://' + addr.address + ':' + addr.port);
});
var sockets = require('./sockets');
sockets.socketServer(app, server);
// sockets.js
var socketio = require('socket.io');
exports.socketServer = function (app, server) {
var io = socketio.listen(server);
io.sockets.on('connection', function (socket) {
...
});
};
Hope that helps!
a similar approach is to pass app into index.js file and initiate http and socketio server there.
//app.js
//regular expressjs configuration stuff
require('./routes/index')(app); //all the app.get should go into index.js
Since app is passed into index.js file, we can do the app.get() routing stuff inside index.js, as well as connecting socketio
//index.js
module.exports = function(app){
var server = require('http').createServer(app)
,io = require('socket.io').listen(server);
app.get('/', function(req, res){
});
server.listen(app.get('port'), function(){
console.log("Express server listening on port " + app.get('port'));
});
io.sockets.on('connection', function(socket){
socket.on('my event', function(data){
console.log(data);
});
});
io.set('log level',1);
//io.sockets.emit(...)

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