1 files changed, 40 insertions, 0 deletions
diff --git a/webapp/django/views/decorators/vary.py b/webapp/django/views/decorators/vary.py
new file mode 100644
index 0000000000..ea1b8d307d
--- /dev/null
+++ b/webapp/django/views/decorators/vary.py
@@ -0,0 +1,40 @@
+try:
+    from functools import wraps
+except ImportError:
+    from django.utils.functional import wraps  # Python 2.3, 2.4 fallback.
+
+from django.utils.cache import patch_vary_headers
+
+def vary_on_headers(*headers):
+    """
+    A view decorator that adds the specified headers to the Vary header of the
+    response. Usage:
+
+       @vary_on_headers('Cookie', 'Accept-language')
+       def index(request):
+           ...
+
+    Note that the header names are not case-sensitive.
+    """
+    def decorator(func):
+        def inner_func(*args, **kwargs):
+            response = func(*args, **kwargs)
+            patch_vary_headers(response, headers)
+            return response
+        return wraps(func)(inner_func)
+    return decorator
+
+def vary_on_cookie(func):
+    """
+    A view decorator that adds "Cookie" to the Vary header of a response. This
+    indicates that a page's contents depends on cookies. Usage:
+
+        @vary_on_cookie
+        def index(request):
+            ...
+    """
+    def inner_func(*args, **kwargs):
+        response = func(*args, **kwargs)
+        patch_vary_headers(response, ('Cookie',))
+        return response
+    return wraps(func)(inner_func)