gistfile1.rb

require 'rubygems'
require 'eventmachine'
require 'evma_httpserver'

class HttpHandler < EM::Connection
  include EM::HttpServer
  
  @@listeners = []
  
  def process_http_request
    resp = EM::DelegatedHttpResponse.new(self)
    
    case @http_path_info
      
    when '/observe'
      @@listeners.push(resp)
      puts "Observed (#{@@listeners.length} total)"
    
    when '/notify'
      @@listeners.each_with_index do |listener, i|
        puts "Notified #{i}"
        listener.status = 200
        listener.content = "Hello World #{i}!"
        listener.send_response
      end
      @@listeners = []
      resp.status = 200
      resp.content = "Success!"
      resp.send_response
    
    else
      resp.status = 200
      resp.content = "Received #{resp.inspect}!"
      resp.send_response
    end
  end
end

EM.run do
  EM.start_server "0.0.0.0", 6000, HttpHandler
  puts 'listening...'
end