Awesome
WebSocket Rack
Rack-based WebSocket server
Usage
Create sample rack config file, and inside build app basing on Rack::WebSocket::Application.
require 'rack/websocket'
class MyApp < Rack::WebSocket::Application
end
map '/' do
run MyApp.new
end
After that just run Rack config from Rack server:
thin -R config.ru start
Done.
Configuration
Rack::WebSocket::Application make following methods available:
initialize
Called once after server is started. This is place for application configuration so each instance variables from here will be available in whole application.
Example:
class MyApp < Rack::WebSocket::Application
def initialize(options = {})
super
@myvar = 4
end
end
It is important to include 'super' in initialize function, so application will be properly configured.
Please notice that in some servers, when 'initialize' is called, EventMachine reactor is not running yet. If you would like to configure EventMachine-based software, then you need to put it inside 'EM.next_tick' block, so this function will be called in first cycle of reactor.
Example:
class MyWebSocket < Rack::WebSocket::Application
def initialize
EM.next_tick { @redis = EM::Hiredis.connect }
end
end
on_open(env)
Called after client is connected. Rack env of client is passed as attribute.
Example:
class MyApp < Rack::WebSocket::Application
def on_open(env)
puts "Client connected"
end
end
on_close(env)
Called after client is disconnected. Rack env of client is passed as attribute.
Example:
class MyApp < Rack::WebSocket::Application
def on_close(env)
puts "Client disconnected"
end
end
on_message(env, msg)
Called after server receive message. Rack env of client is passed as attribute.
Example:
class MyApp < Rack::WebSocket::Application
def on_message(env, msg)
puts "Received message: " + msg
end
end
on_error(env, error)
Called after server catch error. Variable passed is instance of Ruby Exception class.
Example:
class MyApp < Rack::WebSocket::Application
def on_error(env, error)
puts "Error occured: " + error.message
end
end
send_data(data)
Sends data do client.
Example:
class MyApp < Rack::WebSocket::Application
def on_open(env)
send_data "Hello to you!"
end
end
close_websocket
Closes connection.
Example:
class MyApp < Rack::WebSocket::Application
def on_open(env)
close_websocket if env['REQUEST_PATH'] != '/websocket'
end
end
Available variables:
@options
Options passed to app on initialize.
Example:
# In config.ru
map '/' do
run MyApp.new :some => :variable
end
# In application instance
@options # => { :some => :variable }
FAQ
Which WebSocket drafts are supported:
Currently we support drafts -75 and -76 form old(hixie) numeration and all drafts from -00 to -13 from current(ietf-hybi) numeration. Please note that ietf-hybi-13 is currently proposed as final standard.
Which Rack servers are supported?
Currently we are supporting following servers:
- Thin
How to enable debugging?
Just use :backend => { :debug => true } option when initializing your app.
How to enable wss/SSL support?
Thin v1.2.8 has an --ssl option - just use that! :)
How to use function xxx?
Check Thin config - any option supported by Thin(like demonizing, SSL etc.) is supported by WebSocket-Rack.
About
Author: Bernard Potocki
Released under MIT license.
Support
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