socket.io

Installation

npm install socket.io --save

How to use

The following example attaches socket.io to a plain Node.JS HTTP server listening on port 3000.

var server = require('http').createServer();
var io = require('socket.io')(server);
io.on('connection', function(client){
  client.on('event', function(data){});
  client.on('disconnect', function(){});
});
server.listen(3000);

Standalone

var io = require('socket.io')();
io.on('connection', function(client){});
io.listen(3000);

In conjunction with Express

Starting with 3.0, express applications have become request handler functions that you pass to http or http Server instances. You need to pass the Server to socket.io, and not the express application function.

var app = require('express')();
var server = require('http').createServer(app);
var io = require('socket.io')(server);
io.on('connection', function(){ /* … */ });
server.listen(3000);

In conjunction with Koa

Like Express.JS, Koa works by exposing an application as a request handler function, but only by calling the callback method.

var app = require('koa')();
var server = require('http').createServer(app.callback());
var io = require('socket.io')(server);
io.on('connection', function(){ /* … */ });
server.listen(3000);

API

See API.

Debug / logging

Socket.IO is powered by debug. In order to see all the debug output, run your app with the environment variable DEBUG including the desired scope.

To see the output from all of Socket.IO's debugging scopes you can use:

DEBUG=socket.io* node myapp

Testing

npm test

This runs the gulp task test. By default the test will be run with the source code in lib directory.

Set the environmental variable TEST_VERSION to compat to test the transpiled es5-compat version of the code.

The gulp task test will always transpile the source code into es5 and export to dist first before running the test.

License

MIT