+
−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)