Hack Showoff to remotely drive presentation

config.ru

require "showoff"

require 'pusher'
Pusher.app_id = 'insert Pusher app id here'
Pusher.key    = 'insert Pusher key here'
Pusher.secret = 'insert Pusher secret here'

class PresentationController
  def initialize(app)
    @app = app
  end

  def call(env)
    req = Rack::Request.new(env)

    if req.path == '/slide'
      if req.params['sekret'] == 'SecurityThroughObscurityFTW'
        Pusher['presenter'].trigger('slide_change', {
          'slide' => req.params['num']
        })
      end

      [ 204, {}, [] ]
    else
      @app.call env
    end
  end
end

use PresentationController
run ShowOff.new

presenter.js

// Copy pusher.js from http://js.pusherapp.com/1.9/pusher.min.js and dump here.

var presenter = /presenter=(.*)/.exec(window.location.search),
    sekret    = presenter && presenter[1];

if (sekret) {
  $(function() {
    $('body').bind('showoff:show', function() {
      $.post('/slide', { sekret: sekret, num: slidenum });
    });
  });

} else {

  // Enable pusher logging - don't include this in production
  Pusher.log = function(message) {
    if (window.console && window.console.log) window.console.log(message);
  };

  new Pusher('insert Pusher key here')
    .subscribe('presenter')
    .bind('slide_change', function(data) {
      Pusher.log('slide_change', data.slide);
      gotoSlide(data.slide);
    });
}