django1/django/views/decorators/cache.py

59 lines
2.2 KiB
Python

from functools import wraps
from django.middleware.cache import CacheMiddleware
from django.utils.cache import add_never_cache_headers, patch_cache_control
from django.utils.decorators import decorator_from_middleware_with_args
def cache_page(*args, **kwargs):
"""
Decorator for views that tries getting the page from the cache and
populates the cache if the page isn't in the cache yet.
The cache is keyed by the URL and some data from the headers.
Additionally there is the key prefix that is used to distinguish different
cache areas in a multi-site setup. You could use the
get_current_site().domain, for example, as that is unique across a Django
project.
Additionally, all headers from the response's Vary header will be taken
into account on caching -- just like the middleware does.
"""
# 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.
if len(args) != 1 or callable(args[0]):
raise TypeError("cache_page has a single mandatory positional argument: timeout")
cache_timeout = args[0]
cache_alias = kwargs.pop('cache', None)
key_prefix = kwargs.pop('key_prefix', None)
if kwargs:
raise TypeError("cache_page has two optional keyword arguments: cache and key_prefix")
return decorator_from_middleware_with_args(CacheMiddleware)(
cache_timeout=cache_timeout, cache_alias=cache_alias, key_prefix=key_prefix
)
def cache_control(**kwargs):
def _cache_controller(viewfunc):
@wraps(viewfunc)
def _cache_controlled(request, *args, **kw):
response = viewfunc(request, *args, **kw)
patch_cache_control(response, **kwargs)
return response
return _cache_controlled
return _cache_controller
def never_cache(view_func):
"""
Decorator that adds headers to a response so that it will
never be cached.
"""
@wraps(view_func)
def _wrapped_view_func(request, *args, **kwargs):
response = view_func(request, *args, **kwargs)
add_never_cache_headers(response)
return response
return _wrapped_view_func