Web Socket Server

This is a lightweight Web Socket server written in Erlang implementing the protocol described here:

http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-76

Copyright and License

Copyright 2011 Tobias Rodaebel

This software is released under the Apache License, Version 2.0. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Credits

Thanks to Jesse Farmer for a great article about building generalized TCP servers which heavily influenced this software.

http://20bits.com/articles/erlang-a-generalized-tcp-server

Requirements

The Web Socket server requires Erlang/OTP R14A or higher.

Building and Running

In order to build and run the server, enter the following commands:

$ make
$ bin/ewsd

Web Socket Handlers

This library introduces a websocket_handler behavior which aims at providing some convenience for developing new Web Socket handlers.

A typical Web Socket handler consists of the following methods:

init, handle_message, handle_push, handle_close

Included in this distribution you find a brief example on how to implement a simple echo handler.

The Web Socket handler module must be configered in the websocket.app file by adding this tuple {handler, ModuleName} to the environment:

{env, [{port, 8888}, {handler, websocket_echo}, {timeout, 5000}]}

Alternatively, a configuration file can be specified. The examples directory contains a broadcast handler. In order to run the Web Socket server with the related configuration file, enter the following command:

$ bin/ewsd --config=examples/broadcast.config

Now open the examples/broadcast.html file with a Web Socket capable browser.