socket.io Client: Sockets for the rest of us

The socket.io client is basically a simple TCP socket interface implementation. It allows you to establish a realtime connection with a server (see socket.io server here), hiding the complexity of the different transports (WebSocket, forever iframe, XHR long polling, XHR multipart encoded, etc).

How to use

var Socket = io.Socket,
socket = new Socket('localhost');
socket.connect();
socket.send('some data');
socket.addEvent('message', function(data){
	alert('got some data' + data);
});

Features

• Supports

  • WebSocket
  • Adobe Flash Socket
  • ActiveX HTMLFile (IE)
  • Server-Sent Events (Opera)
  • XHR with multipart encoding
  • XHR with long-polling

• On a successful connection, it remembers the transport for next time (stores it in a cookie)

Documentation

new io.Socket(host, [options]);

Options:

• port

    80
  

  The port socket.io server is attached to

• resource

    socket.io
  

  The resource is what allows the socket.io server to identify incoming connections by socket.io clients. In other words, any HTTP server can implement socket.io and still serve other normal, non-realtime HTTP requests.

• transports

    ['websocket', 'server-events', 'flashsocket', 'htmlfile', 'xhr-multipart', 'xhr-polling']
  

  A list of the transports to attempt to utilize (in order of preference)

• transportOptions

    {
    	someTransport: {
    		someOption: true
    	},
    	...
    }
  

  An object containing (optional) options to pass to each transport.

Properties:

• options

  The passed in options combined with the defaults

• connected

  Whether the socket is connected or not.

• connecting

  Whether the socket is connecting or not.

• transport

  The transport instance.

Methods:

• connect

  Establishes a connection

• send(message)

  A string of data to send.

• disconnect

  Closes the connection

• addEvent(event, λ)

  Adds a listener for the event event

• removeEvent(event, λ)

  Removes the listener λ for the event event

Events:

• connect

  Fired when the connection is established and the handshake successful

• message(message)

  Fired when a message arrives from the server

• close

  Fired when the connection is closed. Be careful with using this event, as some transports will fire it even under temporary, expected disconnections (such as XHR-Polling).

• disconnect

  Fired when the connection is considered disconnected.

Credits

Guillermo Rauch guillermo@rosepad.com