EventStream

gistfile1.rb

require 'sinatra'
require 'eventmachine'

class EventStream

  include EventMachine::Deferrable

  def initialize(channel, &block)
    @channel = channel
    @block = block
  end

  def self.create(channel, request, &block)
    EventMachine.next_tick do
      request.env['async.callback'].call [
        200, {'Content-Type' => 'text/event-stream'},
        EventStream.new(channel, &block) ]
    end
    [-1, {}, []]
  end

  def each
    @sid = @channel.subscribe do |event|
      @block.call(event).each do |key, value|
        yield "#{key}: #{value}\n"
      end
      yield "\n"
    end
    errback do
      @channel.unsubscribe @sid
    end
  end

end

events_channel = EM::Channel.new

get '/events' do
    EventStream.create events_channel, request do |event|
      { :id => event }
    end
end

post '/events' do
  events_channel << params[:event]
  nil
end