How do I pass a parent id as an fk to child object's ModelForm using generic class-based views in Django?

Question

I am trying to use Django Generic Class-Based Views to build a CRUD interface to a two-model database. I have a working CRUD interface to the parent model, and am stuck try

Answer 1

With the url that you defined in author_detail.html the author_id variable will be accessible in the view as self.kwargs['author_id']

# views.py
class BookCreate(CreateView):
...
def form_valid(self, form):
    book = form.save(commit=False)
    author_id = form.data['author_id']
    author = get_object_or_404(Author, id=author_id)
    book.author = author
    return super(BookCreate, self).form_valid(form)
...
def get_context_data(self, **kwargs):
    context = super(BookCreate, self).get_context_data(**kwargs)
    context['a_id'] = self.kwargs['author_id']
    return context

Then in your form you can add:

class BookForm(forms.Modelform):
    ...
    def __init__(self, *args, **kwargs):
        self.fields["author_id"] = forms.CharField(widget=forms.HiddenInput())
        super(BookForm, self).__init__(self, *args, **kwargs)

Then in the template:

The form_valid in the view should retrieve the id, get the appropriate author and set that author as the books author. The commit=False prevents the model getting saved at first while you set the author and calling super will result in form.save(commit=True) being called.