The HTML5 WebSocket is bi-directional communication protocol which allows communication over a single socket. It is exposed via JavaScript Interface and only works with the HTML5 compliant browsers.

The HTML5 WebSocket Object has several attributes, methods and events which make WebSocket useful for building online application.

In order to create the HTML5 WebSocket we declare variable and and assign new WebSocket object to it.

        <script>

                //url specifies site we want to connect to and      protocol is optional

                var mySocketObject =     new WebSocket(url, [protocal]);

        </script>

There are two WebSocket Attributes. Let us examine these attributes in details: 

Attribute

Description

Socket.readyState

It represents the state of the HTML5 WebSocket connection with values ranging from 0 to 3. 

Socket.bufferedAmount

It represents the number of bytes beening queued

The HTML5 WebSocket events are available to you once you create WebSocket object as explained above. There are several events available: 

Event Handler

Description

Socket.onopen

It fires when connection is established

Socket.onmessage

It fires when data from the server is received by the client

Socket.onerror

It fires when error occur

Socket.onclose

It fires when connection is being closed

The HTML5 WebSocket object has two distinct methods. These methods are: 

Method

Description

Socket.send()

It sends data using WebSocket connection

Socket.close()

It termines WebSocket existing connection