1 """

     2 Decorator for views that tries getting the page from the cache and

     3 populates the cache if the page isn't in the cache yet.

     4 

     5 The cache is keyed by the URL and some data from the headers. Additionally

     6 there is the key prefix that is used to distinguish different cache areas

     7 in a multi-site setup. You could use the sites.get_current().domain, for

     8 example, as that is unique across a Django project.

     9 

    10 Additionally, all headers from the response's Vary header will be taken into

    11 account on caching -- just like the middleware does.

    12 """

    13 

    14 try:

    15     from functools import wraps

    16 except ImportError:

    17     from django.utils.functional import wraps  # Python 2.3, 2.4 fallback.

    18 

    19 from django.utils.decorators import decorator_from_middleware

    20 from django.utils.cache import patch_cache_control, add_never_cache_headers

    21 from django.middleware.cache import CacheMiddleware

    22 

    23 cache_page = decorator_from_middleware(CacheMiddleware)

    24 

    25 def cache_control(**kwargs):

    26 

    27     def _cache_controller(viewfunc):

    28 

    29         def _cache_controlled(request, *args, **kw):

    30             response = viewfunc(request, *args, **kw)

    31             patch_cache_control(response, **kwargs)

    32             return response

    33 

    34         return wraps(viewfunc)(_cache_controlled)

    35 

    36     return _cache_controller

    37 

    38 def never_cache(view_func):

    39     """

    40     Decorator that adds headers to a response so that it will

    41     never be cached.

    42     """

    43     def _wrapped_view_func(request, *args, **kwargs):

    44         response = view_func(request, *args, **kwargs)

    45         add_never_cache_headers(response)

    46         return response

    47     return wraps(view_func)(_wrapped_view_func)