Django ModelForm with extra fields that are not in the model

Question

I have done a ModelForm adding some extra fields that are not in the model. I use these fields for some calcualtions when saving the form.

The extra fie

Answer 1

First add the field in the form

class CreateForm(forms.ModelForm):

extra_field     = forms.CharField(label = 'extra_field', required = False)

Now while cleaning you data, you need to retrive the extra field from self.data NOT self.cleaned_data

Correct:

 self.data.get('extra_field')

Wrong:

 self.cleaned_data.get('extra_field')