CODEWITHSUNDEEP
node.jssocketsherokuwebsocketsocket.io
Aimee
Aimee

Reputation: 143

Simple node.js socket server

I am trying to create a simple node.js server that will allow my socket based iOS app to send it's GPS coordinates to the server, and the server will broadcast the GPS coordinate to all connected iOS clients. Similarly, the clients are connected to the server using sockets. I tried using some sample code from Heroku's web server. CODE IS EDITED TO INCLUDE ANURAG'S ANSWER

var WebSocketServer = require("ws").Server
var http = require("http")
var express = require("express")
var app = express()
var port = process.env.PORT || 5000

app.use(express.static(__dirname + "/"))

var server = http.createServer(app)
server.listen(port)

console.log("http server listening on %d", port)

var wss = new WebSocketServer({server: server})
console.log("websocket server created")

var connectionList = [];

wss.on("connection", function(ws) {
    console.log("connection");
  connectionList.push(ws);
})

wss.on("message", function(data, id) {
    var mes = server.unmaskMessage(data);
    var str = server.convertToString(mes.message);
    console.log(str);
    var i;
    for(i = 0; i < connectionList.lenth; i++) {
         wss.sendMessage(one, str, connectionList[i]);
    }
});

How do I modify this code to be able to receive messages from my app (via sockets) and then send that message to all other iOS clients connected. (The message is just a simple string)

BONUS QUESTION: Because Heroku makes you use it's environments port (rather than your own specified one), in my iOS app, when I connect to the server, would I just specify the Port that is printed to the console when the server is started.

Any help is appreciated, Thank you! :)

EDIT: For broadcasting to the clients, the code is:

wss.on('connection', function(ws) {
  ws.on('message', function(message) {
    wss.broadcast(message);
  });
});

However how do I receive messages from a client, and how do I make the received message the message to be broadcasted to the other clients.

Upvotes: 3

Views: 3366

Answers (2)

David Dahan
David Dahan

Reputation: 11152

Here is the complete index.js code sothat the server brodcast received messages to clients:

var WebSocketServer = require("ws").Server
var http = require("http")
var express = require("express")
var app = express()
var port = process.env.PORT || 5000

app.use(express.static(__dirname + "/"))

var server = http.createServer(app)
server.listen(port)

console.log("http server listening on %d", port)

var wss = new WebSocketServer({server: server})
console.log("websocket server created")

wss.broadcast = function(data) {
  for (var i in this.clients)
    this.clients[i].send(data);
};


wss.on("connection", function(ws) {

  console.log("websocket connection open");

  ws.on('message', function(message) {
    console.log("message received by server");
    wss.broadcast(message);
    })

  ws.on("close", function() {
    console.log("websocket connection close")
  })
})

Upvotes: 1

Anurag Peshne
Anurag Peshne

Reputation: 1547

On getting the connection you need to store those connections. Then you can send message to all those devices connect to your server using those connections. You may try something like this:

var connectionList = [];
wss.on("connection", function(ws) {
  connectionList.push(ws);
})

wss.on("message", function(data, id) {
    var mes = server.unmaskMessage(data);
    var str = server.convertToString(mes.message);
    console.log(str);
    var i;
    for(i = 0; i < connectionList.lenth; i++) {
         wss.sendMessage(one, str, connectionList[i]);
    }
});

Read more here: https://www.npmjs.com/package/websocketserver

Upvotes: 3

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