Django form view to create and update object model

Question

I have a model called RecordsCategory which has only field called name on two below addresses

1. record_category/create/

2. record_category/update/

how can I write my FormView for both updating and creating?

models.py

class RecordsCategory(models.Model):
    name = models.CharField(max_length=255, blank=True)

views.py

class RecordCategoryView(FormView):
    ?

Answer 1

Use django generic UpdateView and CreateView.

views.py

class RecordCategoryCreateView(CreateView):
    model = RecordsCategory
    fields = ['field name']

repeat the same with UpdateView making sure you make the right changes along the way.

Answer 2

Well, Let's consider a scenario where we create a RecordsCategory and update/edit the RecordsCategory using Django forms.

Suppose you have a certain model as follows:

class RecordsCategory(models.Model):
    name = models.CharField(max_length=255, blank=True)

Now, let's add forms:

class RecordsCategoryForm(forms.ModelForm):
    class Meta:
        model = RecordsCategory
        fields = '__all__'


    def save(self):
        record_category = super(RecordsCategoryForm, self).save(commit=False)
        record_category.save()
        return record_category

If you observe the save method, we are first trying to get the record category object without saving it to the database (via commit=False). This is to make sure that the application doesn't raise IntegrityError(which means we are trying to save to DB without entering/filling mandatory fields). Then we are saving it to the database.

Let's add views for create new record category:

from django.views.generic import FormView

class NewRecordsCategoryView(FormView):
    template_name = "blob/blob.html"
    form_class = RecordsCategoryForm

    def form_valid(self, form):
        form.save()
        return super(NewRecordCategoryView, self).form_valid(form)

    def get_success_url(self, *args, **kwargs):
        return reverse("some url name")

We have overridden form_valid method of NewRecordsCategoryView to save() method that we have overridden above. Specially since we can't access request objects in models/forms, we need to pass to save() method.(we can also pass to __init__ method of form, that's another way).

Now, let's add another view to update the record category object:

class EditRecordsCategoryView(UpdateView) #Note that we are using UpdateView and not FormView
    model = RecordsCategory
    form_class = RecordsCategoryForm
    template_name = "blob/blob.html"

    def form_valid(self, form): # here you should be redirected to the id which you want to change it.
        form.save()
        return super(EditRecordsCategoryView, self).form_valid(form)

    def get_success_url(self, *args, **kwargs):
        return reverse("some url name")

And with these urls:

    ...
    path('record_category/create/', NewUserProfileView.as_view(), name="new-user-profile"),
    path('record_category/(?P<pk>\d+)/update/', EditUserProfileView.as_view(), name="edit-user-profile"),
    ...

And the basic Django template to make the above forms work:

<form method="post">
  {% csrf_token %}
  {{ form.as_p }}

  <input type=submit value="submit" />
</form>

References:

• Adding and editing model objects using Django class based views and forms

• How to reference the newly created object using FormView ^{[stackoverflow]}

• django.views.generic.edit.FormView ^{[django-docs]}

• Django ModelForm: What is save(commit=False) used for? ^{[stackoverflow]}