web/lib/django/views/decorators/cache.py
changeset 29 cc9b7e14412b
parent 0 0d40e90630ef
equal deleted inserted replaced
28:b758351d191f 29:cc9b7e14412b
    12 """
    12 """
    13 
    13 
    14 try:
    14 try:
    15     from functools import wraps
    15     from functools import wraps
    16 except ImportError:
    16 except ImportError:
    17     from django.utils.functional import wraps  # Python 2.3, 2.4 fallback.
    17     from django.utils.functional import wraps  # Python 2.4 fallback.
    18 
    18 
    19 from django.utils.decorators import decorator_from_middleware
    19 from django.utils.decorators import decorator_from_middleware_with_args, available_attrs
    20 from django.utils.cache import patch_cache_control, add_never_cache_headers
    20 from django.utils.cache import patch_cache_control, add_never_cache_headers
    21 from django.middleware.cache import CacheMiddleware
    21 from django.middleware.cache import CacheMiddleware
    22 
    22 
    23 cache_page = decorator_from_middleware(CacheMiddleware)
    23 
       
    24 def cache_page(*args, **kwargs):
       
    25     # We need backwards compatibility with code which spells it this way:
       
    26     #   def my_view(): pass
       
    27     #   my_view = cache_page(my_view, 123)
       
    28     # and this way:
       
    29     #   my_view = cache_page(123)(my_view)
       
    30     # and this:
       
    31     #   my_view = cache_page(my_view, 123, key_prefix="foo")
       
    32     # and this:
       
    33     #   my_view = cache_page(123, key_prefix="foo")(my_view)
       
    34     # and possibly this way (?):
       
    35     #   my_view = cache_page(123, my_view)
       
    36 
       
    37     # We also add some asserts to give better error messages in case people are
       
    38     # using other ways to call cache_page that no longer work.
       
    39     key_prefix = kwargs.pop('key_prefix', None)
       
    40     assert not kwargs, "The only keyword argument accepted is key_prefix"
       
    41     if len(args) > 1:
       
    42         assert len(args) == 2, "cache_page accepts at most 2 arguments"
       
    43         if callable(args[0]):
       
    44             return decorator_from_middleware_with_args(CacheMiddleware)(cache_timeout=args[1], key_prefix=key_prefix)(args[0])
       
    45         elif callable(args[1]):
       
    46             return decorator_from_middleware_with_args(CacheMiddleware)(cache_timeout=args[0], key_prefix=key_prefix)(args[1])
       
    47         else:
       
    48             assert False, "cache_page must be passed either a single argument (timeout) or a view function and a timeout"
       
    49     else:
       
    50         return decorator_from_middleware_with_args(CacheMiddleware)(cache_timeout=args[0], key_prefix=key_prefix)
       
    51 
    24 
    52 
    25 def cache_control(**kwargs):
    53 def cache_control(**kwargs):
    26 
       
    27     def _cache_controller(viewfunc):
    54     def _cache_controller(viewfunc):
    28 
       
    29         def _cache_controlled(request, *args, **kw):
    55         def _cache_controlled(request, *args, **kw):
    30             response = viewfunc(request, *args, **kw)
    56             response = viewfunc(request, *args, **kw)
    31             patch_cache_control(response, **kwargs)
    57             patch_cache_control(response, **kwargs)
    32             return response
    58             return response
       
    59         return wraps(viewfunc, assigned=available_attrs(viewfunc))(_cache_controlled)
       
    60     return _cache_controller
    33 
    61 
    34         return wraps(viewfunc)(_cache_controlled)
       
    35 
       
    36     return _cache_controller
       
    37 
    62 
    38 def never_cache(view_func):
    63 def never_cache(view_func):
    39     """
    64     """
    40     Decorator that adds headers to a response so that it will
    65     Decorator that adds headers to a response so that it will
    41     never be cached.
    66     never be cached.
    42     """
    67     """
    43     def _wrapped_view_func(request, *args, **kwargs):
    68     def _wrapped_view_func(request, *args, **kwargs):
    44         response = view_func(request, *args, **kwargs)
    69         response = view_func(request, *args, **kwargs)
    45         add_never_cache_headers(response)
    70         add_never_cache_headers(response)
    46         return response
    71         return response
    47     return wraps(view_func)(_wrapped_view_func)
    72     return wraps(view_func, assigned=available_attrs(view_func))(_wrapped_view_func)