Develop Reference

Method to link logged Author to Article they created not working

Something is wrong with my method, assign_article_creator. It's supposed to populate the field, custom_user, with the username (email address) of the logged-in user/author, so that the author is associated with any article that they create. But it's not working. In Django Admin, the field custom_user is populated with '----' when an author creates an article. Please help me. Thank you.
models.py
class CustomUser(AbstractBaseUser, PermissionsMixin):
email = models.EmailField(_('email address'), unique=True)
class Articles(models.Model):
custom_user = models.ForeignKey(CustomUser, default=None, null=True,
on_delete=models.SET_NULL)
views.py
class CreateArticle(LoginRequiredMixin, CreateView):
model = Articles
form_class = ArticleForm
template_name = "users/add_article.html"
def assign_article_creator(self, request):
if request.method == 'POST':
form = self.form_class(request, data=request.POST)
if form.is_valid():
instance = form.save(commit=False)
instance.custom_user = request.user
instance.save()
return render(request=request,
template_name ="users/add_article.html", context={"form":
form})

When you extend CreateView, you can't add just any method name you want to the class and expect it to work automatically. Instead, you need to override post() with the custom logic to assign custom_user. (You may want to name this author instead.) You can also leverage super().post() to do most of the work for you. Note that when you override post(), you don't need if request.method == 'POST': because CreateView already does that for you.

I am getting ValueError at /car/offer/4/ Cannot assign "4": "CarRent.car" must be a "Car" instance. when trying to save Car instance to form

I am working on a car rental website for uber drivers in django, from the detailView I need drivers to be able to choose the duration of their rental, and other information will be auto filled to the form from my views.py, i was able to get the driver through request.user, i also need the PK of the car to be rented. searching through here i’ve tried various suggestions by people here, but i keep getting one error after another…
using
self.kwargs['pk'] results in ValueError at /car/offer/4/ Cannot assign "4": "CarRent.car" must be a "Car" instance.
then i tried using
form.car = Car.objects.get(pk= self.kwargs.get('pk')) which results in a AttributeError at /car/offer/4/ 'CarRent' object has no attribute 'is_valid'
can someone please tell me how to get the car instance saved in the CarRent model? any help will be greatly appreciated. Thanks
below is my code (reduced to the relevant bit)
models.py
class Car(models.Model):
car_owner = models.ForeignKey(User, related_name='car_owner', on_delete=models.CASCADE)
class CarRent(models.Model):
car = models.ForeignKey(Car, related_name='rented_car', on_delete=models.CASCADE)
driver = models.ForeignKey(User, related_name='driver_renting', on_delete=models.CASCADE)
rented_weeks = models.BigIntegerField(default=1, choices=WEEK_CHOICES)
forms.py
class RentForm(forms.ModelForm):
class Meta:
model = CarRent
fields = ['rented_weeks']
i’m only displaying the rented weeks as that’s the only information i need from the user.
views.py
class CarView(FormMixin, DetailView):
model = Car
form_class = RentForm
def get_success_url(self):
return reverse('car-details', kwargs={'pk': self.object.pk})
def post(self, request, *args, **kwargs):
if not request.user.is_authenticated:
return HttpResponseForbidden()
self.object = self.get_object()
form = self.get_form()
form = form.save(commit=False)
form.car = self.kwargs['pk']
form.driver = request.user
if form.is_valid():
return self.form_valid(form)
else:
return self.form_invalid(form)
def form_valid(self, form):
form.save()
return super().form_valid(form)

form.car expects a Car object, not a string with the primary key, but you can simply use:
from django.contrib.auth.mixins import LoginRequiredMixin
class CarView(LoginRequiredMixin, FormMixin, DetailView):
# …
def post(self, request, *args, **kwargs):
form = self.get_form()
self.object = self.get_object()
if form.is_valid():
return self.form_valid(form)
else:
return self.form_invalid(form)
def form_valid(self, form):
form.instance.car_id = self.kwargs['pk']
form.instance.driver = self.request.user
form.save()
return super().form_valid(form)
Note: You can limit views to a class-based view to authenticated users with the
LoginRequiredMixin mixin [Django-doc].
Note: It is normally better to make use of the settings.AUTH_USER_MODEL [Django-doc] to refer to the user model, than to use the User model [Django-doc] directly. For more information you can see the referencing the User model section of the documentation.

How to populate my Django Model 'updated_by' field with logged in User automatically using a formset?

I am a beginner with Django and I have been enjoying it so far. I figured out how to use model formsets, but I cannot figure out how to make my form automatically use logged in User as the 'updated_by' field.
models.py
class Inventory(models.Model):
item = models.CharField(max_length=50, unique=True)
stock = models.IntegerField()
par = models.IntegerField()
date_updated = models.DateTimeField(auto_now=True)
updated_by = models.ForeignKey(User, on_delete=models.PROTECT)
def __str__(self):
return self.item
class Profile(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
image = models.ImageField(default='default.jpg', upload_to='profile_pics')
phone = PhoneField(blank='True', help_text='Contact Phone Number')
def __str__(self):
return f'{self.user.username} Profile'
def save(self):
super().save()

I think the problem lies in your views.py. Try getting request.user before saving the form.

i think you should have made form for Inventory if yes(let InvntoryForm) than in view.py file you have done something like this:-
if request.method == 'POST':
Inven_form=InventoryForm(data=request.POST)
if Inven_form.is_valid():
user=Inven_form.save()
#in between add this
Inven_form.updated_by=request.user.username
user.save()

I would use the 'commit=False' argument which will create a new object and assign it without saving to your database. You can then set the user attribute and call save() with no arguments.
For example, this is how I assigned the user attribute to my blog app.
in views.py
if form.is_valid():
# Create a new entry and assign to new_article.
new_article = form.save(commit=False)
# Set the new article attribute to the current user.
new_article.user = request.user
# Save to database now the object has all the required data.
new_article.save()
Here is the full code for the add_article view if this helps.
#login_required
def add_article(request):
""" Add a new article. """
if request.method != 'POST':
# No data submitted, create a blank form.
form = AddArticleForm()
else:
# POST data submitted, process data.
form = AddArticleForm(request.POST, request.FILES)
if form.is_valid():
new_article = form.save(commit=False)
new_article.author = request.user
new_article.save()
return back_to_blog_page()
context = {'form': form}
return render(request, 'add_article.html', context)

Can I somehow call logic from form_valid() in Django tests?

I am trying to test form for Post model creation in my simple forum application. The problem I am having is that after I try to save the form in tests I get an error NOT NULL constraint failed: forum_web_post.user_id because I am assigning the user in the form_valid() method in the view. The user is not passed via the form since the user that creates the post is the signed in user that sent the request.
models.py
class Post(models.Model):
category = models.ForeignKey(Category, on_delete=models.PROTECT)
user = models.ForeignKey(User, on_delete=models.CASCADE)
title = models.CharField(max_length=100)
text = models.TextField()
created_at = models.DateTimeField(auto_now=True)
user is imported form django.contrib.auth.models and Category model looks like this.
class Category(models.Model):
name = models.CharField(max_length=100)
created_at = models.DateTimeField(auto_now=True)
in views.py after the user submits the form he is the redirected to his profile page
views.py
class PostCreate(generic.CreateView):
model = Post
form_class = PostForm
template_name = 'forum_web/post_edit.html'
def form_valid(self, form):
post = form.save(commit=False)
post.user = models.User.objects.get(id=self.request.user.id)
post.save()
return HttpResponseRedirect(reverse_lazy('forum:user_detail', kwargs={'pk': self.request.user.id}))
forms.py
class PostForm(ModelForm):
class Meta:
model = Post
fields = ['category', 'title', 'text']
tests.py
def test_post_form_create_should_pass(self):
# this dict is in setUp() as well as the test_category but for simplicity I will include it in this method
post_data = {
'category': self.test_category.pk,
'title': 'test_post',
'text': 'test_post_text'
}
post_count = Post.objects.count()
form = PostForm(data=self.post_data)
self.assertTrue(form.is_valid())
form.save()
self.assertEqual(post_count + 1, Post.objects.count())
any help would be appreciated!

You are just testing the form. So it doesn't make sense to call a view function in your test. You should manually assign a user to the form's instance using form.instance.user = ... before saving the form in your test, since that's the way the form should be used.
In addition, you should test your view by actually logging in a user and posting the request to the PostCreate view. Here you're testing that the view correctly saves the form (and that your form_valid() method works correctly).
Note: post.user = self.request.user would be better than re-fetching the user from the database using the id. It's redundant.

Django: CreateView don't show field and set it to request.user (ForeignKey)

I use a generic CreateView to let logged in users (Creator) add objects of the model Piece. Since creating a Piece is done by the Creator (logged in user) there is no need for the CreateView to either show or manipulate the 'creator' field. Hence I wish to not show it and set it to the logged in user. However, approaches such as overwriting form_valid or using get_form_kwargs seem not to get it done. Using the form_valid method gives a ValueError:
Cannot assign "<SimpleLazyObject: <User: patrick1>>": "Piece.creator" must be a "Creator" instance.
The solution seems to be just around the corner, I hope.
Tried but did not work:
form_valid method, form_valid method, get_form_kwargs method
My code:
models.py
class Piece(models.Model):
creator = models.ForeignKey('Creator', on_delete=models.SET_NULL, null=True)
title = models.CharField(max_length=200)
summary = models.TextField(max_length=1000, help_text='Enter a brief description of the Piece')
created = models.DateField(null=True, blank=True)
...
from django.contrib.auth.models import User
class Creator(models.Model):
...
user = models.OneToOneField(User, on_delete=models.CASCADE)
...
views.py
class PieceCreate(LoginRequiredMixin, CreateView):
model = Piece
fields = ['title', 'summary', 'created']
initial = {'created': datetime.date.today()}
def form_valid(self, form):
obj = form.save(commit=False)
obj.creator = self.request.user
return super(PieceCreate, self).form_valid(form)
success_url = reverse_lazy('pieces')
Any suggestions are highly appreciated!

obj.creator = Creator.objects.get(user=self.request.user)
or any other solution that will give you Creator instance for current user instead of User. Just as the error message says.
Cannot assign "User: patrick1": "Piece.creator" must be a "Creator" instance.