Django clone model object with class based createview

Question

I want to prepare a new object but wait for user input to create it:

I've added get_form to this view:

class MyCreateView(CreateView):

    def get_form(self, form_class):
        form = super(MyCreateManView, self).get_form(form_class)
        if self.kwargs['ref']:
            new_item = get_object_or_404(models.MyModel, pk = self.kwargs['ref'])
            new_item.pk = None 
            new_item.note = "Copia di " + new_item.note 
            form =  MyForm(instance = new_item)

    def form_valid(self, form):
        ...

In the method, I read the GET parameter 'ref' and precompile the form fields with that data.

But when I submit the data, the form_valid method is not executed and the new object is not created.

Answer 1

When you do,

form  =  MyForm(instance = new_item)

you are not binding the form to any data. This means that the form will never be valid.

I would try overriding get_form_kwargs instead.

def get_form_kwargs(self):
    kwargs = super(MyCreateView, self).get_form_kwargs()
    if self.kwargs['ref']:
        new_item = get_object_or_404(models.MyModel, pk = self.kwargs['ref'])
        ...
        kwargs['instance'] = new_item
    return kwargs