Added 'key_prefix' keyword argument to cache_page()

This was available before r11586, but undocumented.  It has now been
re-added with documentation and explicit support, as it seems like a useful
feature and people were using it before.



git-svn-id: http://code.djangoproject.com/svn/django/trunk@11595 bcc190cf-cafb-0310-a4f2-bffc1f526a37

3 files changed, 25 insertions, 4 deletions

diff --git a/django/views/decorators/cache.py b/django/views/decorators/cache.py
index 6e6835ad96..f051f096a0 100644
--- a/django/views/decorators/cache.py
+++ b/django/views/decorators/cache.py
@@ -20,27 +20,33 @@ from django.utils.decorators import decorator_from_middleware_with_args, auto_ad
 from django.utils.cache import patch_cache_control, add_never_cache_headers
 from django.middleware.cache import CacheMiddleware
 
-def cache_page(*args):
+def cache_page(*args, **kwargs):
     # We need backwards compatibility with code which spells it this way:
     #   def my_view(): pass
     #   my_view = cache_page(my_view, 123)
     # and this way:
     #   my_view = cache_page(123)(my_view)
+    # and this:
+    #   my_view = cache_page(my_view, 123, key_prefix="foo")
+    # and this:
+    #   my_view = cache_page(123, key_prefix="foo")(my_view)
     # and possibly this way (?):
     #   my_view = cache_page(123, my_view)
 
     # We also add some asserts to give better error messages in case people are
     # using other ways to call cache_page that no longer work.
+    key_prefix = kwargs.pop('key_prefix', None)
+    assert not kwargs, "The only keyword argument accepted is key_prefix"
     if len(args) > 1:
         assert len(args) == 2, "cache_page accepts at most 2 arguments"
         if callable(args[0]):
-            return decorator_from_middleware_with_args(CacheMiddleware)(args[1])(args[0])
+            return decorator_from_middleware_with_args(CacheMiddleware)(cache_timeout=args[1], key_prefix=key_prefix)(args[0])
         elif callable(args[1]):
-            return decorator_from_middleware_with_args(CacheMiddleware)(args[0])(args[1])
+            return decorator_from_middleware_with_args(CacheMiddleware)(cache_timeout=args[0], key_prefix=key_prefix)(args[1])
         else:
             assert False, "cache_page must be passed either a single argument (timeout) or a view function and a timeout"
     else:
-        return decorator_from_middleware_with_args(CacheMiddleware)(args[0])
+        return decorator_from_middleware_with_args(CacheMiddleware)(cache_timeout=args[0], key_prefix=key_prefix)
 
 def cache_control(**kwargs):
 
diff --git a/docs/topics/cache.txt b/docs/topics/cache.txt
index 174dbae121..c9fd1b4012 100644
--- a/docs/topics/cache.txt
+++ b/docs/topics/cache.txt
@@ -361,6 +361,17 @@ then requests to ``/foo/1/`` and ``/foo/23/`` will be cached separately, as
 you may expect. But once a particular URL (e.g., ``/foo/23/``) has been
 requested, subsequent requests to that URL will use the cache.
 
+``cache_page`` can also take an optional keyword argument, ``key_prefix``, which
+works in the same way as the ``CACHE_MIDDLEWARE_KEY_PREFIX`` setting for the
+middleware.  It can be used like this::
+
+    my_view = cache_page(my_view, 60 * 15, key_prefix="site1")
+
+Or, using Python 2.4's decorator syntax::
+
+    @cache_page(60 * 15, key_prefix="site1")
+    def my_view(request):
+
 Specifying per-view cache in the URLconf
 ----------------------------------------
 
diff --git a/tests/regressiontests/decorators/tests.py b/tests/regressiontests/decorators/tests.py
index 64d2d7df73..b81a5d665a 100644
--- a/tests/regressiontests/decorators/tests.py
+++ b/tests/regressiontests/decorators/tests.py
@@ -98,6 +98,8 @@ class DecoratorsTest(TestCase):
             return "response"
         my_view_cached = cache_page(123)(my_view)
         self.assertEqual(my_view_cached(HttpRequest()), "response")
+        my_view_cached2 = cache_page(123, key_prefix="test")(my_view)
+        self.assertEqual(my_view_cached2(HttpRequest()), "response")
 
     def test_cache_page_old_style(self):
         """
@@ -107,6 +109,8 @@ class DecoratorsTest(TestCase):
             return "response"
         my_view_cached = cache_page(my_view, 123)
         self.assertEqual(my_view_cached(HttpRequest()), "response")
+        my_view_cached2 = cache_page(my_view, 123, key_prefix="test")
+        self.assertEqual(my_view_cached2(HttpRequest()), "response")
 
 class MethodDecoratorAdapterTests(TestCase):
     def test_auto_adapt_to_methods(self):