cache_page decorator does not work with class based views about django-jimmypage

[yourcelf]

Can you include a stack trace? I hadn't tested with class-based views previously; I suspect there might be something funny going on with the decoration.

Thanks for your time!

Traceback:
File "/Users/tm/.virtualenvs/vidproject/lib/python2.6/site-packages/django/core/handlers/base.py" in get_response
  117.                             response = middleware_method(request, e)
File "/Users/tm/.virtualenvs/vidproject/lib/python2.6/site-packages/django/core/handlers/base.py" in get_response
  111.                         response = callback(request, *callback_args, **callback_kwargs)
File "/Users/tm/.virtualenvs/vidproject/lib/python2.6/site-packages/django/views/generic/base.py" in view
  47.             return self.dispatch(request, *args, **kwargs)
File "/Users/tm/.virtualenvs/vidproject/lib/python2.6/site-packages/django/utils/decorators.py" in _wrapper
  28.             return bound_func(*args, **kwargs)
File "/Users/tm/.virtualenvs/vidproject/src/django-jimmypage/jimmypage/cache.py" in decorated
  110.                 cache.set(key, response.content, self.time)
File "/Users/tm/.virtualenvs/vidproject/lib/python2.6/site-packages/django/template/response.py" in _get_content
  110.             raise ContentNotRenderedError('The response content must be rendered before it can be accessed.')

Exception Type: ContentNotRenderedError at /vid/10:video-2/
Exception Value: The response content must be rendered before it can be accessed.

I pushed some changes to my fork here:

https://github.com/unvs/django-jimmypage/commit/9b65185ede810e3a0e3859d40410dd5657fedd62

seems to work for now - haven't tested it with a proper memcached setup yet

And this is the stack trace for the first error without name = 'cache_page':

Traceback:
File "/Users/tm/.virtualenvs/vidproj/lib/python2.6/site-packages/django/core/handlers/base.py" in get_response
  89.                     response = middleware_method(request)
File "/Users/tm/.virtualenvs/vidproj/lib/python2.6/site-packages/debug_toolbar/middleware.py" in process_request
  70.                 original_urlconf = __import__(getattr(request, 'urlconf', settings.ROOT_URLCONF), {}, {}, ['*'])
File "/Users/tm/Sites/projects/vidproj/conf/urls.py" in <module>
  13. from polsa.views import VideoDetailView, VideoListView
File "/Users/tm/Sites/projects/vidproj/apps/polsa/views.py" in <module>
  17. class VideoDetailView(DetailView):
File "/Users/tm/Sites/projects/vidproj/apps/polsa/views.py" in VideoDetailView
  34.     @method_decorator(cache_page(60*60))
File "/Users/tm/.virtualenvs/vidproj/lib/python2.6/site-packages/django/utils/decorators.py" in method_decorator
  40.     update_wrapper(_dec, decorator)
File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/functools.py" in update_wrapper
  33.         setattr(wrapper, attr, getattr(wrapped, attr))

Exception Type: AttributeError at /vids/10:video-2/
Exception Value: 'cache_page' object has no attribute '__name__'

[yourcelf]

I created an example project with test cases for various decorator uses, and pushed it to master. This made me realize: I don't think you can properly use decorators the way you did in your example. See this bug:

https://code.djangoproject.com/ticket/13879

An alternative that I've used in some projects I've worked on is to implement an "args_method_decorator" which accepts arguments:

def args_method_decorator(decorator, *dargs, **dkwargs):
    """
    Converts a function decorator into a method decorator, with arguments.
    Copied from django.utils.decorators.method_decorator to allow arguments.
    """
    # 'func' is a function at the time it is passed to _dec, but will eventually
    # be a method of the class it is defined it.
    def _dec(func):
        def _wrapper(self, *args, **kwargs):
            @decorator(*dargs, **dkwargs)
            def bound_func(*args2, **kwargs2):
                return func(self, *args2, **kwargs2)
            # bound_func has the signature that 'decorator' expects i.e.  no
            # 'self' argument, but it is a closure over self so it can call
            # 'func' correctly.
            return bound_func(*args, **kwargs)
        # In case 'decorator' adds attributes to the function it decorates, we
        # want to copy those. We don't have access to bound_func in this scope,
        # but we can cheat by using it on a dummy function.
        @decorator(*dargs, **dkwargs)
        def dummy(*args, **kwargs):
            pass
        update_wrapper(_wrapper, dummy)
        # Need to preserve any existing attributes of 'func', including the name.
        update_wrapper(_wrapper, func)

        return _wrapper
    update_wrapper(_dec, decorator)
    # Change the name to aid debugging.
    _dec.__name__ = 'method_decorator(%s)' % decorator.__name__
    return _dec

This is invoked as:

@args_method_decorator(cache_page, 60)
def get(self, request):
    ... 

Please feel free to reopen a ticket if you find that it's still not working properly, once the decorator usage is worked out.