1[![Build Status](https://secure.travis-ci.org/einaros/ws.png)](http://travis-ci.org/einaros/ws)
  2
  3# ws: a node.js websocket library #
  4
  5`ws` is a simple to use websocket implementation, up-to-date against RFC-6455, and [probably the fastest WebSocket library for node.js](http://web.archive.org/web/20130314230536/http://hobbycoding.posterous.com/the-fastest-websocket-module-for-nodejs).
  6
  7Passes the quite extensive Autobahn test suite. See http://einaros.github.com/ws for the full reports.
  8
  9Comes with a command line utility, `wscat`, which can either act as a server (--listen), or client (--connect); Use it to debug simple websocket services.
 10
 11## Protocol support ##
 12
 13* **Hixie draft 76** (Old and deprecated, but still in use by Safari and Opera. Added to ws version 0.4.2, but server only. Can be disabled by setting the `disableHixie` option to true.)
 14* **HyBi drafts 07-12** (Use the option `protocolVersion: 8`, or argument `-p 8` for wscat)
 15* **HyBi drafts 13-17** (Current default, alternatively option `protocolVersion: 13`, or argument `-p 13` for wscat)
 16
 17_See the echo.websocket.org example below for how to use the `protocolVersion` option._
 18
 19## Usage ##
 20
 21### Installing ###
 22
 23`npm install ws`
 24
 25### Sending and receiving text data ###
 26
 27```js
 28var WebSocket = require('ws');
 29var ws = new WebSocket('ws://www.host.com/path');
 30ws.on('open', function() {
 31    ws.send('something');
 32});
 33ws.on('message', function(data, flags) {
 34    // flags.binary will be set if a binary data is received
 35    // flags.masked will be set if the data was masked
 36});
 37```
 38
 39### Sending binary data ###
 40
 41```js
 42var WebSocket = require('ws');
 43var ws = new WebSocket('ws://www.host.com/path');
 44ws.on('open', function() {
 45    var array = new Float32Array(5);
 46    for (var i = 0; i < array.length; ++i) array[i] = i / 2;
 47    ws.send(array, {binary: true, mask: true});
 48});
 49```
 50
 51Setting `mask`, as done for the send options above, will cause the data to be masked according to the websocket protocol. The same option applies for text data.
 52
 53### Server example ###
 54
 55```js
 56var WebSocketServer = require('ws').Server
 57  , wss = new WebSocketServer({port: 8080});
 58wss.on('connection', function(ws) {
 59    ws.on('message', function(message) {
 60        console.log('received: %s', message);
 61    });
 62    ws.send('something');
 63});
 64```
 65
 66### Server sending broadcast data ###
 67
 68```js
 69var WebSocketServer = require('ws').Server
 70  , wss = new WebSocketServer({port: 8080});
 71  
 72wss.broadcast = function(data) {
 73	for(var i in this.clients)
 74		this.clients[i].send(data);
 75};
 76```
 77
 78### Error handling best practices ###
 79
 80```js
 81// If the WebSocket is closed before the following send is attempted
 82ws.send('something');
 83
 84// Errors (both immediate and async write errors) can be detected in an optional callback.
 85// The callback is also the only way of being notified that data has actually been sent.
 86ws.send('something', function(error) {
 87    // if error is null, the send has been completed,
 88    // otherwise the error object will indicate what failed.
 89});
 90
 91// Immediate errors can also be handled with try/catch-blocks, but **note**
 92// that since sends are inherently asynchronous, socket write failures will *not*
 93// be captured when this technique is used.
 94try {
 95    ws.send('something');
 96}
 97catch (e) {
 98    // handle error
 99}
100```
101
102### echo.websocket.org demo ###
103
104```js
105var WebSocket = require('ws');
106var ws = new WebSocket('ws://echo.websocket.org/', {protocolVersion: 8, origin: 'http://websocket.org'});
107ws.on('open', function() {
108    console.log('connected');
109    ws.send(Date.now().toString(), {mask: true});
110});
111ws.on('close', function() {
112    console.log('disconnected');
113});
114ws.on('message', function(data, flags) {
115    console.log('Roundtrip time: ' + (Date.now() - parseInt(data)) + 'ms', flags);
116    setTimeout(function() {
117        ws.send(Date.now().toString(), {mask: true});
118    }, 500);
119});
120```
121
122### wscat against echo.websocket.org ###
123
124    $ npm install -g ws
125    $ wscat -c ws://echo.websocket.org -p 8
126    connected (press CTRL+C to quit)
127    > hi there
128    < hi there
129    > are you a happy parrot?
130    < are you a happy parrot?
131
132### Other examples ###
133
134For a full example with a browser client communicating with a ws server, see the examples folder.
135
136Note that the usage together with Express 3.0 is quite different from Express 2.x. The difference is expressed in the two different serverstats-examples.
137
138Otherwise, see the test cases.
139
140### Running the tests ###
141
142`make test`
143
144## API Docs ##
145
146See the doc/ directory for Node.js-like docs for the ws classes.
147
148## License ##
149
150(The MIT License)
151
152Copyright (c) 2011 Einar Otto Stangvik &lt;einaros@gmail.com&gt;
153
154Permission is hereby granted, free of charge, to any person obtaining
155a copy of this software and associated documentation files (the
156'Software'), to deal in the Software without restriction, including
157without limitation the rights to use, copy, modify, merge, publish,
158distribute, sublicense, and/or sell copies of the Software, and to
159permit persons to whom the Software is furnished to do so, subject to
160the following conditions:
161
162The above copyright notice and this permission notice shall be
163included in all copies or substantial portions of the Software.
164
165THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
166EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
167MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
168IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
169CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
170TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
171SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.