Twisted long polling

comet_clock.py

from twisted.internet import reactor, task
from twisted.web.server import Site
from twisted.web import server
from twisted.web.resource import Resource
import time

class ClockPage(Resource):
    isLeaf = True
    def __init__(self):
        self.presence=[]
        loopingCall = task.LoopingCall(self.__print_time)
        loopingCall.start(1, False)
        Resource.__init__(self)

    def render_GET(self, request):
        request.write('<b>%s</b><br>' % (time.ctime(),))
        self.presence.append(request)
        return server.NOT_DONE_YET

    def __print_time(self):
        for p in self.presence:
            p.write('<b>%s</b><br>' % (time.ctime(),))

resource = ClockPage()
factory = Site(resource)
reactor.listenTCP(8080, factory)
reactor.run()