socket.io

How to use

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

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').Server(app);
var io = require('socket.io')(server);
io.on('connection', function(){ // … });

API

Server

Exposed by require('socket.io').

Server()

Creates a new Server. Works with and without new:

var io = require('socket.io')();
// or
var Server = require('socket.io');
var io = new Server();

Server(opts:Object)

Optionally, the first or second argument (see below) of the Server constructor can be an options object.

The following options are supported:

• static sets the value for Server#static()
• path sets the value for Server#path()

Options are always passed to the engine.io Server that gets created.

Server(srv:http#Server, opts:Object)

Creates a new Server and attaches it to the given srv. Optionally opts can be passed.

Server(port:Number, opts:Object)

Binds socket.io to a new http.Server that listens on port.

Server#static(v:Boolean):Server

If v is true the attached server (see Server#attach) will serve the client files. Defaults to true.

This method has no effect after attach is called.

// pass a server and the `static` option
var io = require('socket.io')(http, { static: false });

// or pass no server and then you can call the method
var io = require('socket.io')();
io.static(false);
io.attach(http);

If no arguments are supplied this method returns the current value.

Server#path(v:String):Server

Sets the path v under which engine.io and the static files will be served. Defaults to /socket.io.

If no arguments are supplied this method returns the current value.

Server#adapter(v:Adapter):Server

Sets the adapter v. Defaults to an instance of the Adapter that ships with socket.io which is memory based (see below).

If no arguments are supplied this method returns the current value.

Server#sockets:Namespace

The default (/) namespace.

Server#attach(srv:http#Server, opts:Object):Server

Attaches the Server to an engine.io instance on srv with the supplied opts (optionally).

Server#attach(port:Number, opts:Object):Server

Attaches the Server to an engine.io instance that is bound to port with the given opts (optionally).

Server#bind(srv:engine#Server):Server

Advanced use only. Binds the server to a specific engine.io Server (or compatible API) instance.

Server#onconnection(socket:engine#Socket):Server

Advanced use only. Creates a new socket.io client from the incoming engine.io (or compatible API) socket.

Server#of(nsp:String):Namespace

Initializes and retrieves the given Namespace by its pathname identifier nsp.

If the namespace was already initialized it returns it right away.

Server#emit

Emits an event to all connected clients. The following two are equivalent:

var io = require('socket.io');
io.sockets.emit('an event sent to all connected clients');
io.emit('an event sent to all connected clients');

For other available methods, see Namespace below.

Namespace

Represents a pool of sockets connected under a given scope identified by a pathname (eg: /chat).

By default the client always connects to /.

Events

• connection / connect. Fired upon a connection.

  Parameters:

  • Socket the incoming socket.

Namespace#name:String

The namespace identifier property.

Socket

A Socket is the fundamental class for interacting with browser clients.

Socket#joined:Array

A list of strings identifying the rooms this socket is in.

Client

The Client class represents an incoming transport (engine.io) connection. A Client can be associated with many multiplexed Socket that belong to different Namespaces.

Adapter

The Adapter is in charge of keeping track of what rooms each socket is connected to, and passing messages to them.

By default the Adapter is memory based. In order to pass messages across multiple processes, make sure to use an appropriate adapter. (configurable through Server#adapter).

License

MIT