Create or Update with a Django ModelForm

I recently had a use case where I needed to have a single form that could act as either a create or update form. The tricky part was that I wouldn’t know which one was necessary until the data was submitted by the user.

To solve this, I started with Django’s generic UpdateView and overwrote the get_object method so that it would either get the existing record or create a new one (using get_or_create) based on the data being submitted. In my case (and the example below), I had two values that determined whether a new record was necessary or if an existing one should be used.

The underlying ModelForm didn’t require any modification (you could even just use Django’s automatically generated ModelForm by specifying the model in your view).

Here’s the code:

from django.views.generic import UpdateView
from forms import MyModelForm
from models import MyModel
class MyUpdateView(UpdateView):
# specify a custom ModelForm
form_class = MyModelForm
# or simply specify the Model
# model = MyModel
def get_object(self, queryset=None):
# get the existing object or created a new one
obj, created = MyModel.objects.get_or_create(col_1=self.kwargs['value_1'], col_2=self.kwargs['value_2'])
return obj

view raw
view.py
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