How to write a decorator for a class based view - object based resolution from view

right now i am using this app to check permissions: django-rules

However, it hasn't been updated in over a year and there is no decorator for "new" (since django 1.3) classes. I would like to be able to use on urls.py like this:

url(r'^casos/(?P<pk>\d+)/editar/$', rules_permission_required('lawsuits.logical_check', raise_exception=True)(CaseUpdateView.as_view()), name='case_edit'),

      

I can't figure out how to get an object from a class view from a decorator. Do you have any ideas? Here's what I have so far:

from django.utils.decorators import available_attrs
def rules_permission_required(perm, queryset=None, login_url=None, raise_exception=False):
    def wrapper(view_func):
        @wraps(view_func, assigned=available_attrs(view_func))
        def inner(request, *args, **kwargs):
            #view_func is the class based view -> <function MyEditView at 0x94e54c4>

            print view_func.get_object() # doesnt work
            print view_func(request, *args, **kwargs).get_object() # doesnt work either

            #any ideas?

            if not request.user.has_perm(perm, obj=obj):
                return redirect_to_login(request, login_url, raise_exception)
            return view_func(request, *args, **kwargs)
        return inner
    return wrapper

      

Thank you very much in advance!

+3


source to share


2 answers


Use method_decorator

for dispatch () method: https://docs.djangoproject.com/en/dev/topics/class-based-views/#decorating-class-based-views

from django.utils.decorators import method_decorator
class ClassBasedView(View):
    @method_decorator(rules_permission_required)
    def dispatch(self, *args, **kwargs):
        return super(ClassBasedView, self).dispatch(*args, **kwargs)

      

Or you can decorate the output of a class method as_view

, either in the url config (as described in the link above) or by storing the instance into a variable.



class ClassBasedView(View):
    def dispatch(self, *args, **kwargs):
        return super(ClassBasedView, self).dispatch(*args, **kwargs)
class_based_view = rules_permission_required(ClassBasedView.as_view())

      

Though I'm not entirely sure if the last example might cause thread safety issues (depends on how Django handles instances). Your best bet is probably to stick with it method_decorator

.

+7


source


I ended up using the class decorator



def rules_permission_required(perm, queryset=None, login_url=None, raise_exception=False):

    def wrapper(cls):                
        def view_wrapper(view_func):
            @wraps(view_func, assigned=available_attrs(view_func))
            def inner(self, request, *args, **kwargs):
                # get object
                obj = get_object_from_classbased_instance(
                        self, queryset, request, *args, **kwargs
                    )

                # do anything you want
            return inner
        cls.dispatch = view_wrapper(cls.dispatch)
        return cls
    return wrapper

      

0


source







All Articles