def head(self):
title = self.title()
return tags.head(
(
title and
tags.title(title)
or None
),
(
tags.script('', src = script)
for script in self.scripts()
),
(
tags.link('', href = style, rel = 'stylesheet', type = 'text/css')
for style in self.styles()
),
''
)
def process(self):
"""Process HTTP Requests for session mode XML snippets.
The client uses discrete and frequent HttpRequests to
aquire new messages and update their prompt and form."""
if debug_lag:
print 'begin lag'
from time import sleep
sleep(debug_lag)
print 'end lag'
factory = self.channel.factory
# get a session
# the request's service is a SessionService
session_service = self.service
try:
# if a session has been specified, attempt to aquire it
if self.args.has_key('session'):
key = self.args['session'][0]
if key != '':
session = session_service[key]
if not session.modes:
session = session_service.generateSession()
else:
session = session_service.generateSession()
else:
session = session_service.generateSession()
# if the request specified a session which has expired or
# or did not exist in the first place:
except KeyError:
# create a fresh session and notify the user that
# their session has been recreated. Use a priority
# message so that it gets sent before the welcome message.
session = session_service.generateSession()
session.priorityMessage(
'The <b>server</b> has begun a new <b>session</b> with you.'
)
# record that this is the last time that the session
# was accessed, so as to avoid expiration until the next
# period of the factory's timeout.
lastAccess = time()
# if the client polls too frequently, give them a
# service temporarily unavailable error
if (
False and
# todo: fix this and turn it back on
session.lastAccess is not None and
lastAccess - session.lastAccess <
factory.sessionPollInterval
):
self.setResponseCode(503) # Service Unavailable
self.finish()
print "Greedy session: %s, %s" % (session.key, self.getHost())
del session_service[session.key]
return
session.lastAccess = lastAccess
try:
if self.args.has_key('command'):
# execute any commands that were sent in the URL or POST body.
commands = self.args['command']
for command in commands:
session.command(command)
# run the optional user defined HttpRequest process handler
session.tick()
session.process(self)
except SessionEndedError:
session = session_service.generateSession()
# send any queued cookies
for key, value in session.cookies:
self.addCookie(key, value)
del session.cookies[:]
# send an XML response including all new messages and updates
# for the client mode, including the current session key
# for future reference.
self.setResponseCode(200) # OK
self.setHeader('Content-type', 'text/xml')
envelope = tags.envelope(
tags.session(session.key),
tags.pollInterval(factory.session_service.pollInterval),
tags.prompt(session.prompt),
tags.silent(session.silent and 'yes' or 'no'),
tags.title(session.title),
tags.messages(
tags.message(message)
for message in session.priorityMessages + session.messages
),
tags.overlays(
tags.overlay(overlay)
for name, overlay in session.overlays.items()
),
)
# this code helps observe that XML HTTP Request responses
# are limited to 8KB in Firefox.
# if len(envelope.xml) > 400:
# print len(envelope.xml)
# eventually, we'll have to trim messages down to discrete
# patches to send to the user document
xml = envelope.xml
if len(xml) > 8 * 1024:
print "Message longer than 8KB (%sKB)." % (len(xml) / 1024)
envelope.writexml(self)
# remove the messages that have been sent from their queues
del session.messages[:]
del session.priorityMessages[:]
session.overlays.clear()
self.finish()
