So I have a CreateView and it works 99% the way I want. If a user enters a letter in an integer field it tells the user to enter a number, if a user leaves a required field blank it tells them that they need to fill it in. This is all great, CreateView handles the errors for me. However, for obvious reasons, I am not letting the user create the slug field, this is created automatically by taking the date and two other fields combining them and slugifying them. If the user attempts to create a record that wouldn't result in a unique slug then the form is invalid but CreateView doesn't give any constructive feedback (unless you are in debug mode, then you get UNIQUE constraint failed).
If I add the code below to my CreateView, then I need to re-define all the error responses that CreateView was handling so nicely before.
def form_invalid(self, form):
return HttpResponse(#define stuff here)
Is there a way I can have CreateView handle invalid forms normally (as if I didn't have def form_invalid(self, form):) except for when there is a slug conflict?
You can do that by calling the parent's class version of form_invalid inside your overriding of form_invalid.
Example:
class MyCreateView(CreateView):
def form_invalid(self, form):
if my_condition: # Check whatever you want
return HttpResponse('reason it failed')
else: # Or call the parent class version
return super(MyCreateView, self).form_invalid(form)
Related
Have created a form but unsure if is right and also unable to add a user, it will show TypeError/
This is how the form I want it to look like
The following is my coding:
class Form_Add_User(forms.Form):
name=forms.CharField(label="Name", max_length=50)
dateofbirth=forms.DateField(label="Date of Birth", widget=forms.widgets.DateInput(format="%m/%d/%Y"))
contactnum=forms.CharField(label="Contact Number", max_length=9)
def adduser(request):
if len(request.POST)>0:
form=Form_Add_User(request.POST)
if(form.is_valid()):
name=form.cleaned_data['name']
dateofbirth=form.cleaned_data['dateofbirth']
contactnum=form.cleaned_data['contactnum']
new_user=User(name=name,dateofbirth=dateofbirth,contactnum=contactnum)
new_user.save()
return redirect('/adduser')
else:
return render(request,'adduser.html',{'form':form})
else:
form=Form_Add_User
return render(request,'adduser.html',{'form':form})
First off: it's always very useful to also post a full error message if you have one. The more info you give us, the easier (and quicker!) is answering your question.
I assume, your User model is not actually django's auth User model (see, if you had posted the model, I wouldn't have to guess).
The form you pass to your template was not instantiated:
#...
else:
form=Form_Add_User() #!!
return render(request,'adduser.html',{'form':form})
I have a model named Post and have a field there called owner (foreign key to User). Of course, only owners can update or delete their own posts.
That being said, I use login_required decorator in the views to make sure the user is logged in but then, I also need to make sure the user trying to update/delete the question is the owner.
As I'm using Django: Generic Editing Views the documentation says I need to use Django: UserPassesTestMixin.
This validation will be done for the update and delete views. DRY, what is the way to go about this? should I create a class named TestUserOwnerOfPost and create a test_func() and then make the update and delete views inherit from it?
Cause that's what I have tried and didn't work, code below:
from django.views.generic.edit import UpdateView
from django.contrib.auth.decorators import login_required
from django.contrib.auth.mixins import UserPassesTestMixin
class TestUserOwnerOfPost(UserPassesTestMixin):
def test_func(self):
return self.request.user == self.post.owner
class EditPost(UpdateView, TestUserOwnerOfPost):
model = Post
#method_decorator(login_required)
def dispatch(self, *args, **kwargs):
return super(EditPost, self).dispatch(*args, **kwargs)
With the code above, every logged-in user in the system can edit/delete any post. What am I doing wrong? am I missing something? thanks.
The first problem is that the order of the classes you inherit is incorrect, as #rafalmp says.
However, fixing that doesn't solve the problem, because the UserPassesTest mixin performs the test before running the view. This means that it's not really suitable to check the owner of self.object, because self.object has not been set yet. Note I'm using self.object instead of self.post -- I'm don't think that the view ever sets self.post but I might be wrong about that.
One option is to call self.get_object() inside the test function. This is a bit inefficient because your view will fetch the object twice, but in practice it probably doesn't matter.
def test_func(self):
self.object = self.get_object()
return self.request.user == self.object.owner
Another approach is to override get_queryset, to restrict it to objects owned by the user. This means the user will get a 404 error if they do not own the object. This behaviour is not exactly the same as the UserPassesTestMixin, which will redirect to a login page, but it might be ok for you.
class OwnerQuerysetMixin(object):
def get_queryset(self):
queryset = super(OwnerQuerysetMixin, self).get_queryset()
# perhaps handle the case where user is not authenticated
queryset = queryset.filter(owner=self.request.user)
return queryset
The order of the classes you inherit from matters. For your access control to work, it must be enforced before UpdateView is executed:
class EditPost(TestUserOwnerOfPost, UpdateView):
Is it possible to extend a generic view to allow user authentication? I want my view to limit the number of returned results from the model if a user is not logged in.
class CustomGalleryDetailView(DetailView):
def get_queryset(self):
if request.user.is_authenticated():
return Gallery.objects.on_site().is_public()
else:
return Gallery.objects.on_site().is_public()[:5]
This returns NameError global name 'request' is not defined.
The reason I want to extend the generic view is that here I am simply overriding a single of many views used by a 3rd party app in my program, and I want to maintain some consistency with the rest of the views which mainly rely on generic views.
just change it to self.request.user.is_authenticated(), so your class will become:
class CustomGalleryDetailView(DetailView):
def get_queryset(self):
if self.request.user.is_authenticated():
return Gallery.objects.on_site().is_public()
else:
return Gallery.objects.on_site().is_public()[:5]
I'm new to the web development world, to Django, and to applications that require securing the URL from users that change the foo/bar/pk to access other user data.
Is there a way to prevent this? Or is there a built-in way to prevent this from happening in Django?
E.g.:
foo/bar/22 can be changed to foo/bar/14 and exposes past users data.
I have read the answers to several questions about this topic and I have had little luck in an answer that can clearly and coherently explain this and the approach to prevent this. I don't know a ton about this so I don't know how to word this question to investigate it properly. Please explain this to me like I'm 5.
There are a few ways you can achieve this:
If you have the concept of login, just restrict the URL to:
/foo/bar/
and in the code, user=request.user and display data only for the logged in user.
Another way would be:
/foo/bar/{{request.user.id}}/
and in the view:
def myview(request, id):
if id != request.user.id:
HttpResponseForbidden('You cannot view what is not yours') #Or however you want to handle this
You could even write a middleware that would redirect the user to their page /foo/bar/userid - or to the login page if not logged in.
I'd recommend using django-guardian if you'd like to control per-object access. Here's how it would look after configuring the settings and installing it (this is from django-guardian's docs):
>>> from django.contrib.auth.models import User
>>> boss = User.objects.create(username='Big Boss')
>>> joe = User.objects.create(username='joe')
>>> task = Task.objects.create(summary='Some job', content='', reported_by=boss)
>>> joe.has_perm('view_task', task)
False
If you'd prefer not to use an external library, there's also ways to do it in Django's views.
Here's how that might look:
from django.http import HttpResponseForbidden
from .models import Bar
def view_bar(request, pk):
bar = Bar.objects.get(pk=pk)
if not bar.user == request.user:
return HttpResponseForbidden("You can't view this Bar.")
# The rest of the view goes here...
Just check that the object retrieved by the primary key belongs to the requesting user. In the view this would be
if some_object.user == request.user:
...
This requires that the model representing the object has a reference to the User model.
In my project, for several models/tables, a user should only be able to see data that he/she entered, and not data that other users entered. For these models/tables, there is a user column.
In the list view, that is easy enough to implement, just filter the query set passed to the list view for model.user = loggged_id.user.
But for the detail/update/delete views, seeing the PK up there in the URL, it is conceivable that user could edit the PK in the URL and access another user's row/data.
I'm using Django's built in class based views.
The views with PK in the URL already have the LoginRequiredMixin, but that does not stop a user from changing the PK in the URL.
My solution: "Does Logged In User Own This Row Mixin"
(DoesLoggedInUserOwnThisRowMixin) -- override the get_object method and test there.
from django.core.exceptions import PermissionDenied
class DoesLoggedInUserOwnThisRowMixin(object):
def get_object(self):
'''only allow owner (or superuser) to access the table row'''
obj = super(DoesLoggedInUserOwnThisRowMixin, self).get_object()
if self.request.user.is_superuser:
pass
elif obj.iUser != self.request.user:
raise PermissionDenied(
"Permission Denied -- that's not your record!")
return obj
Voila!
Just put the mixin on the view class definition line after LoginRequiredMixin, and with a 403.html template that outputs the message, you are good to go.
In django, the currently logged in user is available in your views as the property user of the request object.
The idea is to filter your models by the logged in user first, and then if there are any results only show those results.
If the user is trying to access an object that doesn't belong to them, don't show the object.
One way to take care of all of that is to use the get_object_or_404 shortcut function, which will raise a 404 error if an object that matches the given parameters is not found.
Using this, we can just pass the primary key and the current logged in user to this method, if it returns an object, that means the primary key belongs to this user, otherwise it will return a 404 as if the page doesn't exist.
Its quite simple to plug it into your view:
from django.shortcuts import get_object_or_404, render
from .models import YourModel
def some_view(request, pk=None):
obj = get_object_or_404(YourModel, pk=pk, user=request.user)
return render(request, 'details.html', {'object': obj})
Now, if the user tries to access a link with a pk that doesn't belong to them, a 404 is raised.
You're going to want to look into user authentication and authorization, which are both supplied by [Django's Auth package] (https://docs.djangoproject.com/en/4.0/topics/auth/) . There's a big difference between the two things, as well.
Authentication is making sure someone is who they say they are. Think, logging in. You get someone to entire their user name and password to prove they are the owner of the account.
Authorization is making sure that someone is able to access what they are trying to access. So, a normal user for instance, won't be able to just switch PK's.
Authorization is well documented in the link I provided above. I'd start there and run through some of the sample code. Hopefully that answers your question. If not, hopefully it provides you with enough information to come back and ask a more specific question.
This is a recurring question and also implies a serious security flaw. My contribution is this:
There are 2 basic aspects to take care of.
The first is the view:
a) Take care to add a decorator to the function-based view (such as #login_required) or a mixin to the class-based function (such as LoginRequiredMixin). I find the official Django documentation quite helpful on this (https://docs.djangoproject.com/en/4.0/topics/auth/default/).
b) When, in your view, you define the data to be retrieved or inserted (GET or POST methods), the data of the user must be filtered by the ID of that user. Something like this:
def get(self, request, *args, **kwargs):
self.object = self.get_object(queryset=User.objects.filter(pk=self.request.user.id))
return super().get(request, *args, **kwargs)
The second aspect is the URL:
In the URL you should also limit the URL to the pk that was defined in the view. Something like this:
path('int:pk/blog-add/', AddBlogView.as_view(), name='blog-add'),
In my experience, this prevents that an user sees the data of another user, simply by changing a number in the URL.
Hope it helps.
In django CBV (class based views) you can prevent this by comparing the
user entered pk and the current logged in user:
Note: I tested it in django 4 and python 3.9.
from django.http import HttpResponseForbidden
class UserDetailView(LoginRequiredMixin, DetailView):
model = your_model
def dispatch(self, request, *args, **kwargs):
if kwargs.get('pk') != self.request.user.pk:
return HttpResponseForbidden(_('You do not have permission to view this page'))
return super().dispatch(request, *args, **kwargs)
I can't find a single example of anyone doing this apart from this example, which doesn't help me other than to know where the code needs to sit.
How to prepopulate UserProfile fields in the Django admin?
so this is my code
class QuoteMaterial(models.Model):
name = models.CharField(_('name'), max_length=255)
content = models.TextField(_('content'),
help_text=_('A static priced item used when doing a job. Selectable when creating a quote. '))
price = models.DecimalField(_('price'), max_digits=6, help_text="not sure if this is before or after VAT yet", decimal_places=2, default="0.00")
def get_companies():
return CompanyProfile.objects.filter(user=request.user)
company = models.ForeignKey(CompanyProfile, default=get_companies)
If its not obvious, im trying in the admin section to populate a dropdown with the available companies that belong to the user that is logged in.
my problem is that i dont know how to pass the request object to "get_companies". anyone know of any examples.
You will have to do this overriding in your admin class that extends the ModelAdmin, not in your class that extends models.Model. Specifically, you need to override formfield_for_foreignkey.
From the docs:
class MyModelAdmin(admin.ModelAdmin):
def formfield_for_foreignkey(self, db_field, request, **kwargs):
if db_field.name == "car":
kwargs["queryset"] = Car.objects.filter(owner=request.user)
return super(MyModelAdmin, self).formfield_for_foreignkey(db_field, request, **kwargs)
For your case, it would seem like:
if db_field.name == "company":
kwargs['queryset'] = request.user.company_set.all()
You're mixing up terms.
"Prepopulating" means to fill in a field from another field. It's not how you filter things for the admin popups, since you aren't actually setting the field, but simply limiting choices and letting the user set the field from those.
Aditionally, the default value for a field needs to be a constant, since this is passed down to the database, which can't use a query to set a default.
What you really want is something like the limit_choices_to (docs) parameter for your ForeignKey, but even then, you can't use request for this; it has to work using fields in the model. The reason for this is that, if you based it on the user, then some users would be unable to select the current value set by another user. You don't want company changing itself when the user just wants to change content, for example, just because user doesn't yield the current company in the filter.