joewalnes · September 22, 2012 18:23
diff --git a/README.md b/README.md
diff --git a/slide-server.py b/slide-server.py
 #!/usr/bin/env python

 import tornado.ioloop
 from socket import gethostname
 from tornado.ioloop import IOLoop
 from tornado.options import define, options, parse_command_line
 from tornado.web import Application, RequestHandler, StaticFileHandler
 from tornado.websocket import WebSocketHandler

 # Command line options. Use --help to list
 define('port', default=54321, help='HTTP port to listen on')
 define('autoreload', default=False, help='Automatically watch for Python changes and restart webserver')
 define('staticfiles', default='static', help='Path to static files that shall get served at /static')

 # State
 current_slide = 0

 # Who needs to be notified when the slide changes.
 slide_change_listeners = set()


 class SlidesControlHandler(RequestHandler):
  """Any HTTP request to /slides-control shall increment the current slide
  number and notify all listener."""

  def get(self):
    global current_slide
    current_slide += 1
    print('Slide updated: %d' % current_slide)
    for listener in slide_change_listeners:
      listener(current_slide)
    self.write(str(current_slide))


 class SlidesSubscribeHandler(WebSocketHandler):
  """WebSocket endpoint at /slides-subscribe. Upon connection it shall
  send a message saying what the current slide is, and then send a new
  message whenever the slide changes.
  The protocol is simply a number encoded as a string. e.g. '4'. """

  def open(self):
    print('Websocket opened')
    self.write_message(str(current_slide))
    slide_change_listeners.add(self.on_slide_change)

  def on_close(self):
    print('Websocket closed')
    slide_change_listeners.remove(self.on_slide_change)

  def on_slide_change(self, slide_number):
    self.write_message(str(slide_number))


 def main():
  parse_command_line()
  application = Application([
    (r"/slides-control", SlidesControlHandler),
    (r"/slides-subscribe", SlidesSubscribeHandler),
    (r"/()", StaticFileHandler, dict(path='slides.html')),
  ], debug=options.autoreload, static_path=options.staticfiles)
  application.listen(options.port)
  print('Listening on http://%s:%s/' % (gethostname(), options.port))
  IOLoop.instance().start()


 if __name__ == '__main__':
  main()
diff --git a/slides.html b/slides.html

 <!DOCTYPE html>
 <title>Slides</title>

 <style>
  .slide-number {
    font-size: 40px;
  }
 </style>

 <script src="http://code.jquery.com/jquery-1.8.2.min.js"></script>
 <script>
  $(function() {

    // Subscribe to slide changes
    $('.status').text('Connecting...');
    var ws = new WebSocket('ws://' + document.location.host + '/slides-subscribe');
    ws.onopen = function() {
      $('.status').text('Connected');
    };
    ws.onclose = function() {
      $('.status').text('Lost connection');
    };
    ws.onmessage = function(e) {
      var slideNumber = parseInt(e.data);
      $('.slide-number').text(slideNumber);
    };

    // Increment
    $('.next').click(function() {
      $.get('/slides-control');
    });

    // Update curl instructions
    $('.hostname').text(document.location.host);
  });
 </script>

 <h1>Current Slide</h1>
 <h2 class="slide-number">?</h2>
 <div class="status"></div>

 <p>
  <button class="next">Next</button> or 
  <code>curl http://<span class="hostname"></span>/slides-control</code>
 </p>
	#!/usr/bin/env python

	import tornado.ioloop
	from socket import gethostname
	from tornado.ioloop import IOLoop
	from tornado.options import define, options, parse_command_line
	from tornado.web import Application, RequestHandler, StaticFileHandler
	from tornado.websocket import WebSocketHandler

	# Command line options. Use --help to list
	define('port', default=54321, help='HTTP port to listen on')
	define('autoreload', default=False, help='Automatically watch for Python changes and restart webserver')
	define('staticfiles', default='static', help='Path to static files that shall get served at /static')

	# State
	current_slide = 0

	# Who needs to be notified when the slide changes.
	slide_change_listeners = set()


	class SlidesControlHandler(RequestHandler):
	"""Any HTTP request to /slides-control shall increment the current slide
	number and notify all listener."""

	def get(self):
	global current_slide
	current_slide += 1
	print('Slide updated: %d' % current_slide)
	for listener in slide_change_listeners:
	listener(current_slide)
	self.write(str(current_slide))


	class SlidesSubscribeHandler(WebSocketHandler):
	"""WebSocket endpoint at /slides-subscribe. Upon connection it shall
	send a message saying what the current slide is, and then send a new
	message whenever the slide changes.
	The protocol is simply a number encoded as a string. e.g. '4'. """

	def open(self):
	print('Websocket opened')
	self.write_message(str(current_slide))
	slide_change_listeners.add(self.on_slide_change)

	def on_close(self):
	print('Websocket closed')
	slide_change_listeners.remove(self.on_slide_change)

	def on_slide_change(self, slide_number):
	self.write_message(str(slide_number))


	def main():
	parse_command_line()
	application = Application([
	(r"/slides-control", SlidesControlHandler),
	(r"/slides-subscribe", SlidesSubscribeHandler),
	(r"/()", StaticFileHandler, dict(path='slides.html')),
	], debug=options.autoreload, static_path=options.staticfiles)
	application.listen(options.port)
	print('Listening on http://%s:%s/' % (gethostname(), options.port))
	IOLoop.instance().start()


	if __name__ == '__main__':
	main()

	<!DOCTYPE html>
	<title>Slides</title>

	<style>
	.slide-number {
	font-size: 40px;
	}
	</style>

	<script src="http://code.jquery.com/jquery-1.8.2.min.js"></script>
	<script>
	$(function() {

	// Subscribe to slide changes
	$('.status').text('Connecting...');
	var ws = new WebSocket('ws://' + document.location.host + '/slides-subscribe');
	ws.onopen = function() {
	$('.status').text('Connected');
	};
	ws.onclose = function() {
	$('.status').text('Lost connection');
	};
	ws.onmessage = function(e) {
	var slideNumber = parseInt(e.data);
	$('.slide-number').text(slideNumber);
	};

	// Increment
	$('.next').click(function() {
	$.get('/slides-control');
	});

	// Update curl instructions
	$('.hostname').text(document.location.host);
	});
	</script>

	<h1>Current Slide</h1>
	<h2 class="slide-number">?</h2>
	<div class="status"></div>

	<p>
	<button class="next">Next</button> or
	<code>curl http://<span class="hostname"></span>/slides-control</code>
	</p>