decorator.py

gistfile1.txt

def get_event(request, event_id):
    event = get_object_or_404(Event, pk=event_id)
    user = request.user
    if not event.is_access_allowed(user):
        raise PermissionDenied()
    return event

def takes_event(base_argname="event"):
    id_argname = "%s_id" % base_argname
    def _dec(view_func):
        def _preprocess(request, *args, **kwargs):
            event_id = kwargs[id_argname]
            event = get_event(request, event_id)
            kwargs = kwargs.copy()
            kwargs[base_argname] = event
            del kwargs[id_argname]
            return view_func(request, *args, **kwargs)
        _preprocess.__doc__ = view_func.__doc__
        _preprocess.__dict__ = view_func.__dict__
        return _preprocess
    return _dec