Fixed #580 -- Added mega support for generating Vary headers, including some view decorators, and changed the CacheMiddleware to account for the Vary header. Also added GZipMiddleware and ConditionalGetMiddleware, which are no longer handled by CacheMiddleware itself. Also updated the cache.txt and middleware.txt docs. Thanks to Hugo and Sune for the excellent patches

git-svn-id: http://code.djangoproject.com/svn/django/trunk@810 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 37 insertions, 0 deletions

diff --git a/django/middleware/http.py b/django/middleware/http.py
new file mode 100644
index 0000000000..2bccd60903
--- /dev/null
+++ b/django/middleware/http.py
@@ -0,0 +1,37 @@
+import datetime
+
+class ConditionalGetMiddleware:
+    """
+    Handles conditional GET operations. If the response has a ETag or
+    Last-Modified header, and the request has If-None-Match or
+    If-Modified-Since, the response is replaced by an HttpNotModified.
+
+    Removes the content from any response to a HEAD request.
+
+    Also sets the Date and Content-Length response-headers.
+    """
+    def process_response(self, request, response):
+        now = datetime.datetime.utcnow()
+        response['Date'] = now.strftime('%a, %d %b %Y %H:%M:%S GMT')
+        if not response.has_header('Content-Length'):
+            response['Content-Length'] = str(len(response.content))
+
+        if response.has_header('ETag'):
+            if_none_match = request.META.get('HTTP_IF_NONE_MATCH', None)
+            if if_none_match == response['ETag']:
+                response.status_code = 304
+                response.content = ''
+                response['Content-Length'] = '0'
+
+        if response.has_header('Last-Modified'):
+            last_mod = response['Last-Modified']
+            if_modified_since = request.META.get('HTTP_IF_MODIFIED_SINCE', None)
+            if if_modified_since == response['Last-Modified']:
+                response.status_code = 304
+                response.content = ''
+                response['Content-Length'] = '0'
+
+        if request.META['REQUEST_METHOD'] == 'HEAD':
+            response.content = ''
+
+        return response