Simple Chat with Sinatra

sinatra_chat.rb

# -*- encoding: utf-8 -*-

require 'sinatra'
require 'slim'

set :server, 'thin'
connections = []

get '/' do
  halt slim(:login) unless params[:user]
  slim :chat, :locals => { :user => params[:user].gsub(/\W/, '') }
end

get '/stream', :provides => 'text/event-stream' do
  stream :keep_open do |out|
    connections << out
    out.callback { connections.delete(out) }
  end
end

post '/' do
  connections.each { |out| out << "data: #{params[:msg]}\n\n" }
  # http://ru.wikipedia.org/wiki/Список_кодов_состояния_HTTP#204
  204 # response without entity body
end

__END__

@@ layout
html
  head
    title Simple Chat with Sinatra
    meta charset="utf-8"
    script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"
  body
    == yield

@@ login
form action='/'
  label for='user' User Name:
  input name='user' value=''
  input type='submit' value="GO!"

@@ chat
form
  input id='msg' placeholder='type message here...'

pre id='chat'

javascript:
  // reading
  var es = new EventSource('/stream');
  es.onmessage = function(e) { $('#chat').append(e.data + "\n") };

  // writing
  $("form").live("submit", function(e) {
    $.post('/', {msg: "#{user}: " + $('#msg').val()});
    $('#msg').val(''); $('#msg').focus();
    e.preventDefault();
  });