Notifying with EventSource, Faye, EventMachine

notifier.rb

require 'faye/websocket'

# Configuration:
#
# With rackup
#   map '/notifier' do
#     run Notifier.new
#   end
#
# With Rails, add this to config/routes.rb
#   mount Notifier.new => "/notifier", as: "notifier"
#
# Usage:
#   Notifier::Channel.push 'ahoy'
#

class Notifier

  Channel = EventMachine::Channel.new

  def call(env)
    if Faye::EventSource.eventsource?(env)
      stream = Faye::EventSource.new(env)
      sid = Channel.subscribe do |msg|
        stream.send(msg)
      end
      stream.onclose do
        Channel.unsubscribe(sid)
      end
      stream.rack_response
    else
      [406, {}, ""]
    end
  end

end