id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
13854	List of used decorators on a function	Mitar	nobody	"Sometimes it is useful to be able to check which decorators are already applied to a function (view mostly), especially when you are constructing them dynamically. I am proposing that all decorators in Django maintain a list of used decorators on a function. It is required that all decorators do this for the idea to be useful.

{{{
def user_passes_test(test_func, login_url=None, redirect_field_name=REDIRECT_FIELD_NAME, decorator_id=None):
    """"""
    Decorator for views that checks that the user passes the given test,
    redirecting to the log-in page if necessary. The test should be a callable
    that takes the user object and returns True if the user passes.

    It maintains `decorators` attribute on wrapped function with list of all
    ids of used decorators, where the first one is the first one used.
    """"""
    if not login_url:
        from django.conf import settings
        login_url = settings.LOGIN_URL
    if decorator_id is None:
        decorator_id = id(user_test_required)

    def decorator(view_func):
        def _wrapped_view(request, *args, **kwargs):
            if test_func(request.user):
                return view_func(request, *args, **kwargs)
            path = urlquote(request.get_full_path())
            tup = login_url, redirect_field_name, path
            return HttpResponseRedirect('%s?%s=%s' % tup)

        wrapped_view_func = wraps(view_func, assigned=available_attrs(view_func))(_wrapped_view)
        wrapped_view_func.decorators = []
        if hasattr(view_func, 'decorators'):
            wrapped_view_func.decorators += view_func.decorators
        wrapped_view_func.decorators.append(decorator_id)
        
        return wrapped_view_func

    return decorator
}}}

`decorator_id` can in fact be anything. Developer can for example use a tuple with additional information. In this case it could be maybe useful to use `(id(user_test_required), id(test_func))` to differentiate between different uses of decorator. Or in the case of `permission_required` decorator `perm` parameter could be stored in the tuple.

Of course this functionally can be also made into a decorator. ;-) So we could have a decorator which we would apply to decorators to have them registered in `decorators` attribute.

I am willing to make a patch if there will be confirmation for this idea."		closed	Core (Other)	1.2		wontfix		mmitar@…	Unreviewed	0	0	0	0	0	0