def json_comet_wrapper(request, user_view, fifo_name, time_delta, *args, **kwargs):
response_prev = request.META.get('response_prev', None)
event_flags = request.META.get('event_flags', None)
event_type = request.META.get('event_type', None)
if not response_prev:
transport = request.GET.get('transport', None)
callback = request.GET.get('callback', 'c').replace("'", "").replace('"', '')
domain = request.GET.get('domain', request.META['SERVER_NAME']).replace("'", "").replace('"', '')
view_data = {}
first_request = True
else:
transport = response_prev.transport
callback = response_prev.callback
view_data = response_prev.view_data
first_request = False
# run callback if first request or event (not on timeout)
if event_flags != 1:
keepalive = False
else: # keepalive
keepalive = True
#kwargs.setdefault('response_prev', response_prev)
#kwargs.setdefault('event_flags', event_flags)
kwargs.setdefault('view_data', view_data) # that's going to be changed by callback
kwargs.setdefault('keepalive', keepalive)
kwargs.setdefault('event_type', event_type)
payload = user_view(request, *args, **kwargs)
if not keepalive or payload: # not keepalive or something returned
payload = json.write(payload)
else: #keepalive and empty response
payload = ' '
# produce Response object, for comet application
# first request, not continuation
if event_type == EVENT_CLOSED:
return HttpResponse()
elif first_request:
content, mimetype = comet_start(transport, callback, domain)
response = HttpResponse(content, mimetype=mimetype)
response['Cache-Control'] = 'no-cache'
# append user data
content = comet_continue(transport, payload, callback)
response.write(content)
# if not first_request: -> continue previous request
else:
content = comet_continue(transport, payload, callback)
response = HttpResponse(content)
response.transport = transport
response.callback = callback
response.view_data = view_data
return defer_for_fifo(
response,
fifo_name, time_delta,
request.META['PATH_INFO'])
