pelletier/websocket_tornado_redis.py

## websocket_tornado_redis.py
"""
This is a simple example of WebSocket + Tornado + Redis Pub/Sub usage.
Do not forget to replace YOURSERVER by the correct value.
Keep in mind that you need the *very latest* version of your web browser.
You also need to add Jacob Kristhammar's websocket implementation to Tornado:
Grab it here:
    http://gist.github.com/526746
Or clone my fork of Tornado with websocket included:
    http://github.com/pelletier/tornado
Oh and the Pub/Sub protocol is only available in Redis 2.0.0:
    http://code.google.com/p/redis/downloads/detail?name=redis-2.0.0-rc4.tar.gz

Tested with Chrome 6.0.490.1 dev under OS X.

For questions / feedback / coffee -> @kizlum or thomas@pelletier.im.
Have fun.
"""
import threading
import tornado.httpserver
import tornado.websocket
import tornado.ioloop
import tornado.web
import redis


# This is ugly but I did not want to create multiple files for a so trivial
# example.
TEMPLATE = """
<!DOCTYPE>
<html>
<head>
    <title>Sample test</title>
    <script type="text/javascript" src="http://code.jquery.com/jquery-1.4.2.min.js"></script>
</head>
<body>
    <h1>Hello world</h1>
    <form method='POST' action='./'>
        <textarea name='data' id="data"></textarea>
        <div><input type='submit'></div>
    </form>
    <div id="log"></div>
    <script type="text/javascript" charset="utf-8">
        $(document).ready(function(){

            $('form').submit(function(event){
                var value = $('#data').val();
                $.post("./", { data: value }, function(data){
                    $("#data").val('');
                });
                return false;
            });


            if ("WebSocket" in window) {
              var ws = new WebSocket("ws://YOURSERVER:8888/realtime/");
              ws.onopen = function() {};
              ws.onmessage = function (evt) {
                  var received_msg = evt.data;
                  var html = $("#log").html();
                  html += "<p>"+received_msg+"</p>";
                  $("#log").html(html);
              };
              ws.onclose = function() {};
            } else {
              alert("WebSocket not supported");
            }
        });
    </script>
</body>
</html>
"""


LISTENERS = []


def redis_listener():
    r = redis.Redis(host='YOURSERVER', db=2)
    r.subscribe('test_realtime')
    for message in r.listen():
        for element in LISTENERS:
            element.write_message(unicode(message['data']))


class NewMsgHandler(tornado.web.RequestHandler):
    def get(self):
        self.write(TEMPLATE)

    def post(self):
        data = self.request.arguments['data'][0]
        r = redis.Redis(host='YOURSERVER', db=2)
        r.publish('test_realtime', data)


class RealtimeHandler(tornado.websocket.WebSocketHandler):
    def open(self):
        LISTENERS.append(self)

    def on_message(self, message):
        pass

    def on_close(self):
        LISTENERS.remove(self)


settings = {
    'auto_reload': True,
}

application = tornado.web.Application([
    (r'/', NewMsgHandler),
    (r'/realtime/', RealtimeHandler),
], **settings)


if __name__ == "__main__":
    threading.Thread(target=redis_listener).start()
    http_server = tornado.httpserver.HTTPServer(application)
    http_server.listen(8888)
    tornado.ioloop.IOLoop.instance().start()
	"""
	This is a simple example of WebSocket + Tornado + Redis Pub/Sub usage.
	Do not forget to replace YOURSERVER by the correct value.
	Keep in mind that you need the very latest version of your web browser.
	You also need to add Jacob Kristhammar's websocket implementation to Tornado:
	Grab it here:
	http://gist.github.com/526746
	Or clone my fork of Tornado with websocket included:
	http://github.com/pelletier/tornado
	Oh and the Pub/Sub protocol is only available in Redis 2.0.0:
	http://code.google.com/p/redis/downloads/detail?name=redis-2.0.0-rc4.tar.gz

	Tested with Chrome 6.0.490.1 dev under OS X.

	For questions / feedback / coffee -> @kizlum or thomas@pelletier.im.
	Have fun.
	"""
	import threading
	import tornado.httpserver
	import tornado.websocket
	import tornado.ioloop
	import tornado.web
	import redis


	# This is ugly but I did not want to create multiple files for a so trivial
	# example.
	TEMPLATE = """
	<!DOCTYPE>
	<html>
	<head>
	<title>Sample test</title>
	<script type="text/javascript" src="http://code.jquery.com/jquery-1.4.2.min.js"></script>
	</head>
	<body>
	<h1>Hello world</h1>
	<form method='POST' action='./'>
	<textarea name='data' id="data"></textarea>
	<div><input type='submit'></div>
	</form>
	<div id="log"></div>
	<script type="text/javascript" charset="utf-8">
	$(document).ready(function(){

	$('form').submit(function(event){
	var value = $('#data').val();
	$.post("./", { data: value }, function(data){
	$("#data").val('');
	});
	return false;
	});


	if ("WebSocket" in window) {
	var ws = new WebSocket("ws://YOURSERVER:8888/realtime/");
	ws.onopen = function() {};
	ws.onmessage = function (evt) {
	var received_msg = evt.data;
	var html = $("#log").html();
	html += "<p>"+received_msg+"</p>";
	$("#log").html(html);
	};
	ws.onclose = function() {};
	} else {
	alert("WebSocket not supported");
	}
	});
	</script>
	</body>
	</html>
	"""


	LISTENERS = []


	def redis_listener():
	r = redis.Redis(host='YOURSERVER', db=2)
	r.subscribe('test_realtime')
	for message in r.listen():
	for element in LISTENERS:
	element.write_message(unicode(message['data']))


	class NewMsgHandler(tornado.web.RequestHandler):
	def get(self):
	self.write(TEMPLATE)

	def post(self):
	data = self.request.arguments['data'][0]
	r = redis.Redis(host='YOURSERVER', db=2)
	r.publish('test_realtime', data)


	class RealtimeHandler(tornado.websocket.WebSocketHandler):
	def open(self):
	LISTENERS.append(self)

	def on_message(self, message):
	pass

	def on_close(self):
	LISTENERS.remove(self)


	settings = {
	'auto_reload': True,
	}

	application = tornado.web.Application([
	(r'/', NewMsgHandler),
	(r'/realtime/', RealtimeHandler),
	], **settings)


	if __name__ == "__main__":
	threading.Thread(target=redis_listener).start()
	http_server = tornado.httpserver.HTTPServer(application)
	http_server.listen(8888)
	tornado.ioloop.IOLoop.instance().start()