committing to schema-evolution

merge from HEAD



git-svn-id: http://code.djangoproject.com/svn/django/branches/schema-evolution@3937 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 17 insertions, 2 deletions

diff --git a/django/middleware/cache.py b/django/middleware/cache.py
index 80c8626db8..58800b24da 100644
--- a/django/middleware/cache.py
+++ b/django/middleware/cache.py
@@ -1,7 +1,6 @@
 from django.conf import settings
 from django.core.cache import cache
 from django.utils.cache import get_cache_key, learn_cache_key, patch_response_headers
-from django.http import HttpResponseNotModified
 
 class CacheMiddleware(object):
     """
@@ -10,6 +9,11 @@ class CacheMiddleware(object):
 
     Only parameter-less GET or HEAD-requests with status code 200 are cached.
 
+    If CACHE_MIDDLEWARE_ANONYMOUS_ONLY is set to True, only anonymous requests
+    (i.e., those node made by a logged-in user) will be cached. This is a
+    simple and effective way of avoiding the caching of the Django admin (and
+    any other user-specific content).
+
     This middleware expects that a HEAD request is answered with a response
     exactly like the corresponding GET request.
 
@@ -23,20 +27,31 @@ class CacheMiddleware(object):
     This middleware also sets ETag, Last-Modified, Expires and Cache-Control
     headers on the response object.
     """
-    def __init__(self, cache_timeout=None, key_prefix=None):
+    def __init__(self, cache_timeout=None, key_prefix=None, cache_anonymous_only=None):
         self.cache_timeout = cache_timeout
         if cache_timeout is None:
             self.cache_timeout = settings.CACHE_MIDDLEWARE_SECONDS
         self.key_prefix = key_prefix
         if key_prefix is None:
             self.key_prefix = settings.CACHE_MIDDLEWARE_KEY_PREFIX
+        if cache_anonymous_only is None:
+            self.cache_anonymous_only = getattr(settings, 'CACHE_MIDDLEWARE_ANONYMOUS_ONLY', False)
+        else:
+            self.cache_anonymous_only = cache_anonymous_only
 
     def process_request(self, request):
         "Checks whether the page is already cached and returns the cached version if available."
+        if self.cache_anonymous_only:
+            assert hasattr(request, 'user'), "The Django cache middleware with CACHE_MIDDLEWARE_ANONYMOUS_ONLY=True requires authentication middleware to be installed. Edit your MIDDLEWARE_CLASSES setting to insert 'django.contrib.auth.middleware.AuthenticationMiddleware' before the CacheMiddleware."
+
         if not request.method in ('GET', 'HEAD') or request.GET:
             request._cache_update_cache = False
             return None # Don't bother checking the cache.
 
+        if self.cache_anonymous_only and request.user.is_authenticated():
+            request._cache_update_cache = False
+            return None # Don't cache requests from authenticated users.
+
         cache_key = get_cache_key(request, self.key_prefix)
         if cache_key is None:
             request._cache_update_cache = True