# -*- coding: utf-8 -*-
"""
sockjs.tornado.transports.xhr
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Xhr-Polling transport implementation
"""
import logging
from tornado.web import asynchronous
from sockjs.tornado import proto
from sockjs.tornado.transports import pollingbase
from sockjs.tornado.util import bytes_to_str
LOG = logging.getLogger("tornado.general")
[docs]class XhrPollingTransport(pollingbase.PollingTransportBase):
"""xhr-polling transport implementation"""
name = 'xhr'
@asynchronous
[docs] def post(self, session_id):
# Start response
self.preflight()
self.handle_session_cookie()
self.disable_cache()
# Get or create session without starting heartbeat
if not self._attach_session(session_id, False):
return
# Might get already detached because connection was closed in on_open
if not self.session:
return
if not self.session.send_queue:
self.session.start_heartbeat()
else:
self.session.flush()
[docs] def send_pack(self, message, binary=False):
if binary:
raise Exception('binary not supported for XhrPollingTransport')
self.active = False
try:
self.set_header('Content-Type', 'application/javascript; charset=UTF-8')
self.set_header('Content-Length', len(message) + 1)
self.write(message + '\n')
self.flush(callback=self.send_complete)
except IOError:
# If connection dropped, make sure we close offending session instead
# of propagating error all way up.
self.session.delayed_close()
[docs]class XhrSendHandler(pollingbase.PollingTransportBase):
[docs] def post(self, session_id):
self.preflight()
self.handle_session_cookie()
self.disable_cache()
session = self._get_session(session_id)
if session is None or session.is_closed:
self.set_status(404)
return
data = self.request.body
if not data:
self.write("Payload expected.")
self.set_status(500)
return
try:
messages = proto.json_decode(bytes_to_str(data))
except:
# TODO: Proper error handling
self.write("Broken JSON encoding.")
self.set_status(500)
return
try:
session.on_messages(messages)
except Exception:
LOG.exception('XHR incoming')
session.close()
self.set_status(500)
return
self.set_status(204)
self.set_header('Content-Type', 'text/plain; charset=UTF-8')