Django: is_secure() decorator not working - django

I'm converting some FBVs with signals to CBVs, so I have this decorator:
def ensure_https(view_func):
def _checkssl(request, *args, **kwargs):
print request.is_secure()
if not settings.DEBUG and not request.is_secure():
url_str = request.build_absolute_uri()
url_str = url_str.replace('http://', 'https://')
return HttpResponseRedirect(url_str)
return view_func(request, *args, **kwargs)
return _checkssl
and added it to a function in a class based view, as so:
class ExampleTemplateView(TemplateView):
template_name = 'example.html'
#ensure_https
def dispatch(self, request, *args, **kwargs):
...
return HttpResponseRedirect(/hello/')
But I get the following error:
'ExampleTemplateView' object has no attribute 'is_secure'
However, when I use this decorator on a function-based view, it works just fine. Should I be using a particular CBV?
If you need anymore code or info, please let me know. Thanks for your help!

I think you have signal and decorator confused as the pattern in your code is a decorator. Depending on what you're doing there might be better alternatives to where you put the URL redirection logic. I'm thinking webserver(nginx), HTTP Strict Transport Security HTTP header or middleware. Having said that, from the django docs:
To decorate every instance of a class-based view, you need to decorate
the class definition itself. To do this you apply the decorator to the
dispatch() method of the class.
A method on a class isn’t quite the same as a standalone function, so
you can’t just apply a function decorator to the method – you need to
transform it into a method decorator first. The method_decorator
decorator transforms a function decorator into a method decorator so
that it can be used on an instance method. For example:
from django.contrib.auth.decorators import login_required
from django.utils.decorators import method_decorator
from django.views.generic import TemplateView
class ProtectedView(TemplateView):
template_name = 'secret.html'
#method_decorator(login_required)
def dispatch(self, *args, **kwargs):
return super(ProtectedView, self).dispatch(*args, **kwargs)

Related

Redirect anonymous users to log in (don't show them anything)

Django 1.9.6.
I want to absolutely disable the whole website from viewing by anonymous users. Anonymous users will always be redirected to login page.
I have created a general view. The problem is that subclasses of GeneralView may not just render a template but perform some calculations or just be of different kinds: DetailView, ListView etc.
class GeneralView(View):
def get(self, request, template):
if not request.user.is_authenticated() and request.user.is_active:
return redirect("auth_login")
else:
return render(request, template)
If I try to inherit, the code gets clumsy:
class HomePageView(GeneralView):
def get(self, request, template):
super().get(self, request)
Well, what can I do here? I get error message that my get method doesn't return HttpResponse.
I can rewrite get method of the superclass to return status code. Then check it in the subclass. But this seems to be garbage.
In other words I'm lost in clouds of inheritance. Could you give me a kick here how always to redirect anonymous users to login page, whereas let logged in users see everything.
Thank you in advance.
You could use the UserPassesTestMixin for this.
from django.core.urlresolvers import reverse_lazy
class GeneralView(UserPassesTestMixin, View):
def test_func(self):
# I assume you missed out the brackets in your question and actually wanted 'if not (request.user.is_authenticated() and request.user.is_active)'
return request.user.is_authenticated() and request.user.is_active
login_url = reverse_lazy('auth_login')
The mixin overrides dispatch, so you won't have to call super() when you override get() in your view.
class HomePageView(GeneralView):
def get(self, request):
...
I think your error for get method not returning belongs to not putting a return statement. in fact, in get method of the child class you should do:
class HomePageView(GeneralView):
def get(self, request, template):
return super().get(self, request)
That should solve the error
If you have lots of views and you do not want to touch any one you can just use Middleware for this issue. Try code below:
import traceback
from django.contrib.auth.decorators import login_required
class RejectAnonymousUsersMiddleware(object):
def process_view(self, request, view_func, view_args, view_kwargs):
current_route_name = resolve(request.path_info).url_name
if current_route_name in settings.AUTH_EXEMPT_ROUTES:
return
if request.user.is_authenticated:
return
return login_required(view_func)(request, *view_args, **view_kwargs)
Cautions:
You must add this middleware to the bottommost of middleware section
of settings.py
You should put this variable in settings.py
AUTH_EXEMPT_ROUTES = ('register', 'login', 'forgot-password')
New versions of Django provides the #login_required decorator. If an anonymous user tries to access the view, the system redirects to the login page.
from django.contrib.auth.decorators import login_required
#login_required
def my_view(request):
...
It can be used in function views, as shown above, or generic views (using #method_decorator, usually in dispatch method)
from django.contrib.auth.decorators import login_required
from django.utils.decorators import method_decorator
from django.views.generic import TemplateView
#method_decorator(login_required, name='dispatch')
class ProtectedView(TemplateView):
template_name = 'secret.html'

Django #login_required not redirecting to login page

I am using class based views in Django. #login_required decorator is not redirecting to login page. It still shows the profile page.
class ProfileView(TemplateView):
template_name='profile.html'
#login_required(login_url='/accounts/login/')
def dispatch(self, *args, **kwargs):
return super(ProfileView, self).dispatch(*args, **kwargs)
Can anyone help me. I m new to Django and any help would be appreciated.
Thanks in advance
You need to apply a method_decorator first and then pass it the login_required function decorator.
A method on a class isn’t quite the same as a standalone function, so you can’t just apply a function decorator to the method. You need to transform it into a method decorator first.
To make it more clear, Django's view decorators return a function with a signature (request, *args, **kwargs) but for class based-views, the signature should be of the form (self, request, *args, **kwargs). Now, what the method_decorator does is that it transforms the first signature to the second.
From docs on decorating Class-based Views:
The method_decorator decorator transforms a function decorator into
a method decorator so that it can be used on an instance method.
from django.contrib.auth.decorators import login_required
from django.utils.decorators import method_decorator
class ProfileView(TemplateView):
template_name='profile.html'
#method_decorator(login_required(login_url='/accounts/login/'))
def dispatch(self, *args, **kwargs):
return super(ProfileView, self).dispatch(*args, **kwargs)
When using class-based views, it's preferred to use the LoginRequiredMixin rather than the #login_required decorator. It performs essentially the same function.
class ProfileView(LoginRequiredMixin, TemplateView):
template_name='profile.html'

Class based View: redirect if logged in, else render template

How can I achieve this in the most generic way? I thought of overriding get(), but I'd have to override too many methods. Also tried with as_view() but I can't access the request from there.
I also tried adding a <meta http-equiv="refresh" content="0;url" /> in the template, but I throught that was not the best approach.
I doubt you want to override as_view unless you are doing something exceptionally odd. It returns a function that is used as the view. The function it returns does little more than call dispatch.
You can override the specific method you want. eg get, alternatively, if you want to override all methods (get, post, etc), you should override dispatch.
from django.shortcuts import redirect
from django.views.generic import TemplateView
class MyView(TemplateView):
template_name = 'my_app/my_template.html'
def dispatch(self, request, *args, **kwargs):
if request.user.is_authenticated:
return redirect('my-other-view')
return super(MyView, self).dispatch(request, *args, **kwargs)
CCBV.co.uk is a good reference for learning django's class based views. Disclaimer: I built it.
I'll copy #meshy's answer with a little edit, request.user.is_authenticated is a bool and you cannot call it. Change just this bit in dispatch method:
...
def dispatch(self, request, *args, **kwargs):
if request.user.is_authenticated:
....

Add object level permission to generic view

The situation is pretty simple:
I'm writing a multi-user blog system. The system should prevent non-owner to edit or delete a blog post. In my view I use generic view.
class BlogUpdateView(UpdateView):
...
I know I should use #method_decorator to decorate dispatch method. However, most example is just #method_decorator(login_required) or model level permission. How can apply object level permission to check whether request.user is the author of this blog post?
For example, I tried to use django-authority apps, and I have a BlogPermission class in this file. and I tried to define a method in this class e.g.
def blog_edit(self, ??, ??)
what should I put into this method?
And then call this like:
#method_decorator(permission_required('blog_permission.blog_edit(???)'))
What should I pass in here?
Update: After read method_decorator code, I find it can only accept function without argument. I think that's why permission_required doesn't work here. But what's the work around about this?
Update solution:
In dispatch method, I check the user permission and then return HttpResponseForbidden() if the user does not meet the permission.
You can do it using class-based-views:
class BlogEdit(UpdateView):
model = Blog
def dispatch(self, request, *args, **kwargs):
if not request.user.has_perm('blog_permission.blog_edit'):
return HttpResponseForbidden()
return super(BlogEdit, self).dispatch(request, *args, **kwargs)
# OR (for object-level perms)
def get_object(self, *args, **kwargs):
obj = super(BlogEdit, self).get_object(*args, **kwargs)
if not obj.user == self.request.user:
raise Http404 # maybe you'll need to write a middleware to catch 403's same way
return obj
Another option is to use UserPassesTestMixin (or user_passes_test for function-based).
class UserPassesTestMixin
When using class-based views, you can use the
UserPassesTestMixin to do this.
test_func()
You have to override the test_func() method of the class to
provide the test that is performed. Furthermore, you can set any of
the parameters of AccessMixin to customize the handling of
unauthorized users:
from django.contrib.auth.mixins import UserPassesTestMixin
class MyView(UserPassesTestMixin, View):
def test_func(self):
return self.request.user.email.endswith('#example.com')
We can now check if the self.request.user is allowed to process the details passed into the self.request.GET or self.request.POST.
class MyView(UserPassesTestMixin, View):
raise_exception = True # To not redirect to the login url and just return 403. For the other settings, see https://docs.djangoproject.com/en/3.2/topics/auth/default/#django.contrib.auth.mixins.AccessMixin
def test_func(self):
return (
self.request.user.is_staff
or self.request.user.has_perm('app.change_blog')
or self.request.user.email.endswith('#company.staff.com')
or is_requested_object_accessible(self.request.user, self.request.GET, self.request.POST) # If you have a custom checker
)
...

How to use permission_required decorators on django class-based views

I'm having a bit of trouble understanding how the new CBVs work. My question is this, I need to require login in all the views, and in some of them, specific permissions. In function-based views I do that with #permission_required() and the login_required attribute in the view, but I don't know how to do this on the new views. Is there some section in the django docs explaining this? I didn't found anything. What is wrong in my code?
I tried to use the #method_decorator but it replies "TypeError at /spaces/prueba/ _wrapped_view() takes at least 1 argument (0 given)"
Here is the code (GPL):
from django.utils.decorators import method_decorator
from django.contrib.auth.decorators import login_required, permission_required
class ViewSpaceIndex(DetailView):
"""
Show the index page of a space. Get various extra contexts to get the
information for that space.
The get_object method searches in the user 'spaces' field if the current
space is allowed, if not, he is redirected to a 'nor allowed' page.
"""
context_object_name = 'get_place'
template_name = 'spaces/space_index.html'
#method_decorator(login_required)
def get_object(self):
space_name = self.kwargs['space_name']
for i in self.request.user.profile.spaces.all():
if i.url == space_name:
return get_object_or_404(Space, url = space_name)
self.template_name = 'not_allowed.html'
return get_object_or_404(Space, url = space_name)
# Get extra context data
def get_context_data(self, **kwargs):
context = super(ViewSpaceIndex, self).get_context_data(**kwargs)
place = get_object_or_404(Space, url=self.kwargs['space_name'])
context['entities'] = Entity.objects.filter(space=place.id)
context['documents'] = Document.objects.filter(space=place.id)
context['proposals'] = Proposal.objects.filter(space=place.id).order_by('-pub_date')
context['publication'] = Post.objects.filter(post_space=place.id).order_by('-post_pubdate')
return context
There are a few strategies listed in the CBV docs:
Decorate the view when you instantiate it in your urls.py (docs)
from django.contrib.auth.decorators import login_required
urlpatterns = [
path('view/',login_required(ViewSpaceIndex.as_view(..)),
...
]
The decorator is applied on a per-instance basis, so you can add it or remove it in different urls.py routes as needed.
Decorate your class so every instance of your view is wrapped (docs)
There's two ways to do this:
Apply method_decorator to your CBV dispatch method e.g.,
from django.utils.decorators import method_decorator
from django.contrib.auth.decorators import login_required
#method_decorator(login_required, name='dispatch')
class ViewSpaceIndex(TemplateView):
template_name = 'secret.html'
If you're using Django < 1.9 (which you shouldn't, it's no longer supported) you can't use method_decorator on the class, so you have to override the dispatch method manually:
from django.contrib.auth.decorators import login_required
class ViewSpaceIndex(TemplateView):
#method_decorator(login_required)
def dispatch(self, *args, **kwargs):
return super(ViewSpaceIndex, self).dispatch(*args, **kwargs)
Use a mixin like django.contrib.auth.mixins.LoginRequiredMixin outlined well in the other answers here:
from django.contrib.auth.mixins import LoginRequiredMixin
class MyView(LoginRequiredMixin, View):
login_url = '/login/'
redirect_field_name = 'redirect_to'
Make sure you place the mixin class first in the inheritance list (so Python's Method Resolution Order algorithm picks the Right Thing).
The reason you're getting a TypeError is explained in the docs:
Note:
method_decorator passes *args and **kwargs as parameters to the decorated method on the class. If your method does not accept a compatible set of parameters it will raise a TypeError exception.
Here is my approach, I create a mixin that is protected (this is kept in my mixin library):
from django.contrib.auth.decorators import login_required
from django.utils.decorators import method_decorator
class LoginRequiredMixin(object):
#method_decorator(login_required)
def dispatch(self, request, *args, **kwargs):
return super(LoginRequiredMixin, self).dispatch(request, *args, **kwargs)
Whenever you want a view to be protected you just add the appropriate mixin:
class SomeProtectedViewView(LoginRequiredMixin, TemplateView):
template_name = 'index.html'
Just make sure that your mixin is first.
Update: I posted this in way back in 2011, starting with version 1.9 Django now includes this and other useful mixins (AccessMixin, PermissionRequiredMixin, UserPassesTestMixin) as standard!
Here's an alternative using class based decorators:
from django.utils.decorators import method_decorator
def class_view_decorator(function_decorator):
"""Convert a function based decorator into a class based decorator usable
on class based Views.
Can't subclass the `View` as it breaks inheritance (super in particular),
so we monkey-patch instead.
"""
def simple_decorator(View):
View.dispatch = method_decorator(function_decorator)(View.dispatch)
return View
return simple_decorator
This can then be used simply like this:
#class_view_decorator(login_required)
class MyView(View):
# this view now decorated
For those of you who use Django >= 1.9, it's already included in django.contrib.auth.mixins as AccessMixin, LoginRequiredMixin, PermissionRequiredMixin and UserPassesTestMixin.
So to apply LoginRequired to CBV(e.g. DetailView):
from django.contrib.auth.mixins import LoginRequiredMixin
from django.views.generic.detail import DetailView
class ViewSpaceIndex(LoginRequiredMixin, DetailView):
model = Space
template_name = 'spaces/space_index.html'
login_url = '/login/'
redirect_field_name = 'redirect_to'
It's also good to keep in mind GCBV Mixin order: Mixins must go on the left side, and the base view class must go in the right side. If the order is different you can get broken and unpredictable results.
I realise this thread is a bit dated, but here's my two cents anyway.
with the following code:
from django.utils.decorators import method_decorator
from inspect import isfunction
class _cbv_decorate(object):
def __init__(self, dec):
self.dec = method_decorator(dec)
def __call__(self, obj):
obj.dispatch = self.dec(obj.dispatch)
return obj
def patch_view_decorator(dec):
def _conditional(view):
if isfunction(view):
return dec(view)
return _cbv_decorate(dec)(view)
return _conditional
we now have a way to patch a decorator, so it will become multifunctional. This effectively means that when applied to a regular view decorator, like so:
login_required = patch_view_decorator(login_required)
this decorator will still work when used the way it was originally intended:
#login_required
def foo(request):
return HttpResponse('bar')
but will also work properly when used like so:
#login_required
class FooView(DetailView):
model = Foo
This seems to work fine in several cases i've recently come across, including this real-world example:
#patch_view_decorator
def ajax_view(view):
def _inner(request, *args, **kwargs):
if request.is_ajax():
return view(request, *args, **kwargs)
else:
raise Http404
return _inner
The ajax_view function is written to modify a (function based) view, so that it raises a 404 error whenever this view is visited by a non ajax call. By simply applying the patch function as a decorator, this decorator is all set to work in class based views as well
Use Django Braces. It provides a lot of useful mixins that is easily available.
It has beautiful docs. Try it out.
You can even create your custom mixins.
http://django-braces.readthedocs.org/en/v1.4.0/
Example Code:
from django.views.generic import TemplateView
from braces.views import LoginRequiredMixin
class SomeSecretView(LoginRequiredMixin, TemplateView):
template_name = "path/to/template.html"
#optional
login_url = "/signup/"
redirect_field_name = "hollaback"
raise_exception = True
def get(self, request):
return self.render_to_response({})
In my code I have written this adapter to adapt member functions to a non-member function:
from functools import wraps
def method_decorator_adaptor(adapt_to, *decorator_args, **decorator_kwargs):
def decorator_outer(func):
#wraps(func)
def decorator(self, *args, **kwargs):
#adapt_to(*decorator_args, **decorator_kwargs)
def adaptor(*args, **kwargs):
return func(self, *args, **kwargs)
return adaptor(*args, **kwargs)
return decorator
return decorator_outer
You can simply use it like this:
from django.http import HttpResponse
from django.views.generic import View
from django.contrib.auth.decorators import permission_required
from some.where import method_decorator_adaptor
class MyView(View):
#method_decorator_adaptor(permission_required, 'someapp.somepermission')
def get(self, request):
# <view logic>
return HttpResponse('result')
If it's a site where the majority of pages requires the user to be logged in, you can use a middleware to force login on all views except some who are especially marked.
Pre Django 1.10 middleware.py:
from django.contrib.auth.decorators import login_required
from django.conf import settings
EXEMPT_URL_PREFIXES = getattr(settings, 'LOGIN_EXEMPT_URL_PREFIXES', ())
class LoginRequiredMiddleware(object):
def process_view(self, request, view_func, view_args, view_kwargs):
path = request.path
for exempt_url_prefix in EXEMPT_URL_PREFIXES:
if path.startswith(exempt_url_prefix):
return None
is_login_required = getattr(view_func, 'login_required', True)
if not is_login_required:
return None
return login_required(view_func)(request, *view_args, **view_kwargs)
views.py:
def public(request, *args, **kwargs):
...
public.login_required = False
class PublicView(View):
...
public_view = PublicView.as_view()
public_view.login_required = False
Third-party views you don't want to wrap can be made excempt in the settings:
settings.py:
LOGIN_EXEMPT_URL_PREFIXES = ('/login/', '/reset_password/')
It has been a while now and now Django has changed so much.
Check here for how to decorate a class-based view.
https://docs.djangoproject.com/en/2.2/topics/class-based-views/intro/#decorating-the-class
The documentation did not include an example of "decorators that takes any argument". But decorators that take arguments are like this:
def mydec(arg1):
def decorator(func):
def decorated(*args, **kwargs):
return func(*args, **kwargs) + arg1
return decorated
return deocrator
so if we are to use mydec as a "normal" decorator without arguments, we can do this:
mydecorator = mydec(10)
#mydecorator
def myfunc():
return 5
So similarly, to use permission_required with method_decorator
we can do:
#method_decorator(permission_required("polls.can_vote"), name="dispatch")
class MyView:
def get(self, request):
# ...
I've made that fix based on Josh's solution
class LoginRequiredMixin(object):
#method_decorator(login_required)
def dispatch(self, *args, **kwargs):
return super(LoginRequiredMixin, self).dispatch(*args, **kwargs)
Sample usage:
class EventsListView(LoginRequiredMixin, ListView):
template_name = "events/list_events.html"
model = Event
This is super easy with django > 1.9 coming with support for PermissionRequiredMixin and LoginRequiredMixin
Just import from the auth
views.py
from django.contrib.auth.mixins import LoginRequiredMixin
class YourListView(LoginRequiredMixin, Views):
pass
For more details read Authorization in django
If you are doing a project which requires variety of permission tests, you can inherit this class.
from django.contrib.auth.decorators import login_required
from django.contrib.auth.decorators import user_passes_test
from django.views.generic import View
from django.utils.decorators import method_decorator
class UserPassesTest(View):
'''
Abstract base class for all views which require permission check.
'''
requires_login = True
requires_superuser = False
login_url = '/login/'
permission_checker = None
# Pass your custom decorator to the 'permission_checker'
# If you have a custom permission test
#method_decorator(self.get_permission())
def dispatch(self, *args, **kwargs):
return super(UserPassesTest, self).dispatch(*args, **kwargs)
def get_permission(self):
'''
Returns the decorator for permission check
'''
if self.permission_checker:
return self.permission_checker
if requires_superuser and not self.requires_login:
raise RuntimeError((
'You have assigned requires_login as False'
'and requires_superuser as True.'
" Don't do that!"
))
elif requires_login and not requires_superuser:
return login_required(login_url=self.login_url)
elif requires_superuser:
return user_passes_test(lambda u:u.is_superuser,
login_url=self.login_url)
else:
return user_passes_test(lambda u:True)
Here the solution for permission_required decorator:
class CustomerDetailView(generics.GenericAPIView):
#method_decorator(permission_required('app_name.permission_codename', raise_exception=True))
def post(self, request):
# code...
return True