django1/django/middleware/http.py

32 lines
1.1 KiB
Python

from django.utils.cache import get_conditional_response
from django.utils.http import http_date, parse_http_date_safe, unquote_etag
class ConditionalGetMiddleware(object):
"""
Handles conditional GET operations. If the response has an ETag or
Last-Modified header, and the request has If-None-Match or
If-Modified-Since, the response is replaced by an HttpNotModified.
Also sets the Date and Content-Length response-headers.
"""
def process_response(self, request, response):
response['Date'] = http_date()
if not response.streaming and not response.has_header('Content-Length'):
response['Content-Length'] = str(len(response.content))
etag = response.get('ETag')
last_modified = response.get('Last-Modified')
if last_modified:
last_modified = parse_http_date_safe(last_modified)
if etag or last_modified:
return get_conditional_response(
request,
etag=unquote_etag(etag),
last_modified=last_modified,
response=response,
)
return response