How to get created object in CreateView

Question

Here I am using CreateView to create item and after that i am redirecting user to update other fields of currently created object.

Here my code:

Views.py

class DynamicCreate(CreateView):
    model = Dynamic
    form_class = DynamicForm
    template_name = 'book/dynamic_create.html'

    def form_valid(self, form):
        book = form.save(commit=False)
        book.user = User.objects.get(pk=(self.request.user.pk))
        book.save()
        return reverse('book:dynamicupdate', args=(self.object.id))


Urls.py

url(r'^book/create/$', views.DynamicCreate.as_view(), name='dynamiccreate'),
url(r'^book/delete/(?P<pk>[\w]+)/$', views.DynamicDelete.as_view(), name='dynamicdelete'),
url(r'^book/update/(?P<pk>[\w]+)/$', views.DynamicUpdate.as_view(), name='dynamicupdate'),

But Here I am getting error:

Exception Type:     AttributeError
Exception Value:    'NoneType' object has no attribute 'id'

I go through other previously asked question like This, But I don't know What I am missing here. My CreateView is able to create/save data in Table but it is not able to redirect me to update View Page.

`return reverse('book:dynamicupdate', args=(self.object.id))` this line giving me error. i am creating object after that i am trying to get its ID/PK to redirect to Update that object ... but self.object.id have no value .. it is returning me None, is there any other way to get created object id ? — Pankaj Jackson, Jun 17 '16 at 09:02
But we just agreed that your object is `book`. So why are you using `self.object` there? — Daniel Roseman, Jun 17 '16 at 09:05
Thanks for Correcting me Daniel i got it, it was just a mistake. I corrected it by `return redirect('book:dynamicupdate', book.id)` I changed `reverse` to `redirect` and `object` to `book` — Pankaj Jackson, Jun 17 '16 at 09:24

score 3 · Accepted Answer · answered Jun 17 '16 at 14:56

The form_valid method inherited from ModelFormMixin includes logic to set self.object to the newly created object, but your overriding method uses the book variable instead. Changing the args to reference book as mentioned above works fine.

Another option would be to replace the book variable with self.object, if only to follow the example set by the default method.

score 1 · Answer 2 · answered Jun 17 '16 at 09:36

I Fixed it by changing from return reverse('book:dynamicupdate', args=(self.object.id)) to return redirect('book:dynamicupdate', book.id)

reverse need ViewName not url so i changed reverse to redirect and here my object was book so i replaced self.object with book

Thanks @Daniel Roseman for help

score 1 · Answer 3 · answered Dec 07 '18 at 13:39

As explained by solarissmoke 'form_valid' must return a response object not a url!

I would then write:

class DynamicCreate(CreateView):
    model = Dynamic
    form_class = DynamicForm
    template_name = 'book/dynamic_create.html'
    success_url = reverse("dynamic_list")

    def form_valid(self, form):
        # Catch an instance of the object
        book = form.save(commit=False)
        book.user_id = self.request.user.id
        book.save()
        self.success_url = reverse('book:dynamic_detail', args=[str(book.id)])
        return super(DynamicCreate, self).form_valid(form)

Note: book.user.id = self.request.user.id instead of the user instance

Even cleaner, add get_absolute_url in model.py

def get_absolute_url(self):
    return reverse('dynamic_detail', args=[str(self.id)])

And refer to this function in the view:

class DynamicCreate(CreateView):
    model = Dynamic
    form_class = DynamicForm
    template_name = 'book/dynamic_create.html'
    success_url = reverse("book_list")

    def form_valid(self, form):
        # Catch an instance of the object
        book = form.save(commit=False)
        book.user_id = self.request.user.id
        book.save()
        self.success_url = self.model.get_absolute_url(book)
        return super(DynamicCreate, self).form_valid(form)

score 0 · Answer 4 · answered Jun 17 '16 at 09:05

0

Try changing that line to:

return reverse('book:dynamicupdate', args=(book.id))

self.object is not defined anywhere in your code.

answered Jun 17 '16 at 09:05

wobbily_col

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BKO · Answer 5 · 2023-04-29T02:37:14.703

By defining get_absolute_url in model you can redirect to "book:dynamicupdate" with pk of created/updated instance.

models.py

from django.db import models
from django.urls import reverse


class Dynamic(models.Model):
    ...

    def get_absolute_url(self):
        return reverse("book:dynamicupdate", kwargs={"pk": self.pk})

urls.py

app_name = 'book'
urlpatterns = [
    path('/path/<int:pk>/', views.YourUpdateView.as_view(), name='dynamicupdate'),
]

See https://docs.djangoproject.com/en/4.2/topics/class-based-views/generic-editing/#model-forms

How to get created object in CreateView

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