I've been trying to make a basic notification system that uses rooms in Socket.io. However, for some reason, it only works every other time you refresh the page.
I've simplified the code to make it easier to debug, but the issue remains. Each time I refresh the page, everything seems to work except joining a room (which only works half the time). What could be going on?
edit: I'm using Socket.io version 1.1.0 and Node.js version 0.10.31
edit2: Added FunnyLookinHat's suggestion (but it still doesn't solve the problem)
Client-Side Code:
socket = io.connect('example.com:8081'),
socket.on('connect', function () {
socket.on('startup', function(data) {
console.log(data.message);
});
socket.emit('joinRoom');
});
Server-Side Code:
var io = require('socket.io').listen(8081);
io.sockets.on('connection', function (socket) {
console.log(socket.id + ' connected!');
socket.emit('startup', { message: 'Socket started!' });
socket.on('joinRoom', function(){
console.log(socket.id + ' joining room lobby'); // prints on every other request
socket.join('lobby');
});
socket.on('disconnect', function() {
console.log(socket.id + ' disconnected!');
});
});
Client Console:
Socket started!
(refreshed page)
Socket started!
Server Console:
UIBqVuOiF1fegMIMAAAB connected!
UIBqVuOiF1fegMIMAAAB joining room lobby
UIBqVuOiF1fegMIMAAAB disconnected!
(refreshed page)
x3nMilBOjjFVjBFJAAAC connected!
(after about a minute once the client window has been closed or refreshed)
x3nMilBOjjFVjBFJAAAC disconnected!
Race condition! Try doing the following in your client code:
socket = io.connect('example.com:8081'),
socket.on('connect', function () {
socket.on('startup', function(data) {
console.log(data.message);
});
socket.emit('joinRoom');
});
Related
server.js
var express = require('express');
var app = express();
var server = require('http').createServer(app);
var io = require('socket.io')(server);
app.use(express.static(__dirname + '/public'));
io.on('connection', function(client) {
console.log('Client connected...');
client.on('join', function(data) {
console.log(data);
io.emit('messages', 'Hello');
});
});
index.html
<script>
var socket = io.connect('http://localhost:7777');
socket.on('connect', function(data) {
socket.emit('join', 'Hello World from client');
});
socket.on('messages', function(data) {
alert(data);
});
</script>
I tried to implement very basic of Socket.io.
However, data sending from client to server is available but from server to client doesn't work.
In the command running server.js, 'Hello World from client' is printed. However, alert window doesn't work in the web browser.(I've also tried to console.log).
How to solve this?
Editted
I've put server.js codes in the app.get('/', function(req, res)){ ... }
Then, it doesn't work. Why it doesn't work in app.get?
Try this, I hope it works:
io.on('connection', function(client) {
console.log('Client connected...');
client.on('join', function(data) {
console.log(data);
io.emit('join', data); //this code sending data from server to client
});
});
If you're just trying to fetch some data with an Ajax call such as /test, then there is no need to use socket.io. That's just a classic request/response.
app.get('/test', function(req, res) {
// collect your data and then send it as a response
res.json(data);
});
If you're just trying to incorporate data into a web page that is requested, then you can use res.render() with the template engine of your choice (ejs, handlebars, pug, etc...). That would typically look like this:
app.get('/test', function(req, res) {
// collect your data and then pass it to res.render() to render your
// your template using that data
res.render('someTemplateName', data);
});
The main thing that socket.io is useful for is "pushing" data from server to client without a client request. So, if something happened on the server that the client was not aware of and the server wanted to tell the client about it, then socket.io would be used for that. The classic example is a chat app. Person A sends a chat message to the server that is addressed to Person B. The server receives that message and then needs to "push" it to Person B. That would be perfect for an already connected socket.io connection because the server can just push the data directly to the Person B client, something the server can't do with request/response (since there is no request from person B).
If you still think you need socket.io, then please describe exactly what you're trying to do with it (step by step what you're trying to send to the client).
socket.on("message",function (reply_data) {
console.log('inside on message functions ')
console.log(reply_data);
})
please change 'messages' to "message" that worked for me
I want to use the websocket in my RN project. And I did it using the ws at server side and the RN built-in websocket implementation.
But it seems not so convinient since I use socket.io before.
So I tried to use socket.io:
In RN:
import './userAgent'
import io from "socket.io-client/socket.io"
In component:
componentDidMount() {
this.socket = io('https://localhost:4080',{jsonp: false});
this.socket.on('hello', (msg) =>{
this.setState({response:msg})
});
}
In the server:
io.on('connection', function(socket){
socket.emit('hello','hello world')
console.log('a user connected');
socket.on('disconnect',function(){
console.log('user disconnected')
})
})
And in userAgent.js
window.navigator.userAgent = 'react-native';
That is just the result I googled and they said it will work. But for me, the chrome debugger stopped at:
function load() {
var r;
try {
r = exports.storage.debug;
} catch(e) {}
return r;
}
And it says the storage is not defined.
Then I looked into the socket.io.js and find that the exports.storage is window.localStorage. So I disabled the remote js debug, and the code began running.
But the server continues to log : a user connected . as if my RN app is keeping on connecting to the server. And it seems the socket.on() did not work at client side.
react-native version:0.27.2
socket.io-client version:1.4.8
Anyone knows where is going wrong?
Well,finally I found the solution after looking through the socket.io source.
It seems that the socket.io does not use 'websocket' as transport defaultly. It will use the 'polling' in my case, so just explicityly set it :
componentDidMount() {
var socket = io('http://localhost:4080', { jsonp: false, transports: ['websocket'] })
socket.on('hello', (msg) => {
//do something
});
}
Now it works.
But what still confuses me is that in brower client I do not set the transports and it just work well but in react-native it doesn't. Not figured out why.
Error: The connection to <websocket> was interrupted while the page was loading.
Source File: localhost/socket.io/node_modules/socket.io-client/dist/socket.io.js
Line: 2371
I am new to socket.io and I have tried to search for this, but I didn't get an answer.
Websocket is interrupted when I refresh page on Firefox. That's why server side is waiting to authorise client.
Here is code:
server.js
var app = require('http').createServer(handler),
io = require('socket.io').listen(app),
fs = require('fs')
app.listen(8080);
function handler(req, res) {
fs.readFile(__dirname + '/index.html',
function (err, data) {
if (err) {
res.writeHead(500);
return res.end('Error loading index.html');
}
res.writeHead(200);
res.end(data);
});
}
io.sockets.on('connection', function (socket) {
socket.emit('news', {
hello: 'world'
});
socket.on('my other event', function (data) {
//alert(JSON.stringify(data));
console.log(data);
});
});
index.html
<script src="node_modules/socket.io-client/dist/socket.io.js"></script>
<script>
var socket = io.connect('http://localhost:8080');
socket.on('news', function (data) {
alert(JSON.stringify(data));
console.log(data);
socket.emit('my next event', { my: 'data' });
});
</script>
It happens because, you are not closing your open websocket.
This code would remove this error:
$(window).on('beforeunload', function(){
socket.close();
});
This seems to be an open bug in Firefox (as of 2015-03-29):
https://bugzilla.mozilla.org/show_bug.cgi?id=712329
The workaround (for now) is to call close() on the websocket on beforeunload, as Alexander pointed out.
Update 2016-04: According to Bugzilla, this will be fixed in Firefox 48
I was just running through the Socket.IO tutorials and I ran into this exact problem. I tried the posted solutions but they didn't seem to work at all.
After some fiddling and some screaming and some rubber-ducking, I finally figured out what the issue was. The issue is that it's trying to connect to the socket before the socket variables have been properly initialized. Javascript boo boo #1.
If you will ammend your file to include jQuery and then wrap your functions like so:
<script src="/socket.io/socket.io.js"></script>
<script src="https://code.jquery.com/jquery-2.1.3.min.js"></script>
<script>
$(function(){
var socket = io.connect('http://localhost:8080');
socket.on('news', function (data) {
alert(JSON.stringify(data));
console.log(data);
socket.emit('my next event', { my: 'data' });
});
});
</script>
You will have much more success.
What impact does this have on your application? My guess is that it's just not great to see an error in the console.
The problem here is that you are seeing Firefox loggin this error and there's nothing you can do about it. It's not possible to capture this error with a try...catch block or via websocket.onerror/websocket.onclose.
See: How do I catch a WebSocket connection interruption?
Related:
Should WebSocket.onclose be triggered by user navigation or refresh?
Firefox - Race condition allows ghost WebSocket connections to live after tab closed
I've had this problem with our custom Undertow-based webserver for years -- my problem was that my server was not responding to the socket close message.
Based on a comment by Jan Wielemaker I checked my socket close handler code for AbstractReceiveListener.onFullCloseMessage and realized I had not called the super method. After adding super.close() the socket closes cleanly on the client and no error is emitted.
One solution is to put a timeout on the disconnect event.
setTimeout(() => {
$('#offlineModal').modal('show')
}, 5000)
Is there any callback for the io.connect() method on the client side? I would like to print some text about connection failure, otherwise proceed normally with the site's socket interactions.
Sure, checkout the documentation for Socket.IO-client with the examples there:
https://github.com/LearnBoost/socket.io-client#sockets-for-the-rest-of-us
socket.on('connect', function () {
// socket connected
});
In the current release of socket.io (1.3.x) you can use the connect_error event or the reconnect_failed event:
var socket = io(serverUrl);
socket.on('connect_error', function() {
console.log('Connection failed');
});
socket.on('reconnect_failed', function() {
console.log('Reconnection failed');
});
See: https://github.com/Automattic/socket.io-client#events
I want to make a web page for give the client the news of his friends every 1 second using socket.io + node.js.
My codes :
Client :
var socket = io.connect('http://localhost:port');
socket.on('connect', function(){
socket.emit('hello', 'Hello guest');
});
socket.on('news_by_server', function(data){
alert(data);
});
setInterval(function(){
socket.emit('news', 'I want news :D ');
}, 1000);
server:
var io = require('socket.io').listen(port);
io.sockets.on('connection', function (socket) {
socket.on('hello', function(data){
console.log('new client connected');
});
socket.on('news', function(data){
socket.emit('news_by_server', 1);
});
});
that's the mains codes, but my question is about the INTERVAL, is it good the make realtime news or there's a way better then it.
There is no need for the client to ask for news. You can force the server if you want to emit every 1 second - as long as there are clients connected, they will receive updates. If there are no clients connected, you will see in the logs that nothing happens.
On the server
setInterval(function(){
socket.emit('news_by_server', 'Cow goes moo');
}, 1000);
On the client
socket.on('news_by_server', function(data){
alert(data);
});
That's pretty much the standard way to do it. If you've not already looked the example apps page on socket.io, there's a beibertweet example that does just this using setInterval.
Also there's a slightly more advanced example on this blog.
Plus .. I found Ryan Dahls's intro on YouTube really useful for understanding the basics of node operation.
Hope that helps.