Initializing Grouped model Form does not work

[Drife59]

Hi,

I wanted to initialized a grouped model form using datas in session.

Here is my code commented:

        LigneProduitFormSet2 = modelformset_factory(ProduitCommande, extra=1)

        initial=[]
        #Just for the test, get only the first item from Session, id and qte
        id_produit, quantite = panier.panier.popitem()
         
        #Get corresponding product object
        produit = Produit.objects.get(id=id_produit)
        #Product object has a ManyToManyField relation to Cuisson, getting corresponding object
        cuissons = produit.cuisson_dispo.all()
        #Creating corresponding object for initialization
        ligne_produit = {"produit": produit, "cuisson":cuissons, "quantite": quantite, 
                         "prix_unitaire":produit.prix, "prix_ligne": (produit.prix * float(quantite))}
        initial.append(ligne_produit)
         
        # This is working 
        formset = LigneProduitFormSet2(initial)
         
        #This is breaking everything
        for form in formset:
            pass
            #print(form.as_table())

If my understanding of the documentation is correct, I should be able to initialize the data like this.
" As with regular formsets, it’s possible to specify initial data for forms in the formset by specifying an initial parameter when instantiating the model formset class returned by modelformset_factory() "

If I delete the initial parameter, my code is working, even my template is properly generated.
the loading from tha database is also working.

Here is the ful stacktrace:

Traceback:
File "/usr/local/lib/python3.4/dist-packages/django/core/handlers/base.py" in get_response
  111.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/usr/local/lib/python3.4/dist-packages/django/contrib/auth/decorators.py" in _wrapped_view
  21.                 return view_func(request, *args, **kwargs)
File "/home/drife/projet/crepes_bretonnes/blog/views.py" in commande_boulangerie
  166.         for form in formset:
File "/usr/local/lib/python3.4/dist-packages/django/forms/formsets.py" in __iter__
  72.         return iter(self.forms)
File "/usr/local/lib/python3.4/dist-packages/django/utils/functional.py" in __get__
  55.         res = instance.__dict__[self.func.__name__] = self.func(instance)
File "/usr/local/lib/python3.4/dist-packages/django/forms/formsets.py" in forms
  141.         forms = [self._construct_form(i) for i in xrange(self.total_form_count())]
File "/usr/local/lib/python3.4/dist-packages/django/forms/formsets.py" in total_form_count
  114.             return min(self.management_form.cleaned_data[TOTAL_FORM_COUNT], self.absolute_max)
File "/usr/local/lib/python3.4/dist-packages/django/forms/formsets.py" in management_form
  93.             if not form.is_valid():
File "/usr/local/lib/python3.4/dist-packages/django/forms/forms.py" in is_valid
  162.         return self.is_bound and not bool(self.errors)
File "/usr/local/lib/python3.4/dist-packages/django/forms/forms.py" in errors
  154.             self.full_clean()
File "/usr/local/lib/python3.4/dist-packages/django/forms/forms.py" in full_clean
  353.         self._clean_fields()
File "/usr/local/lib/python3.4/dist-packages/django/forms/forms.py" in _clean_fields
  362.             value = field.widget.value_from_datadict(self.data, self.files, self.add_prefix(name))
File "/usr/local/lib/python3.4/dist-packages/django/forms/widgets.py" in value_from_datadict
  228.         return data.get(name, None)

Exception Type: AttributeError at < my url>
Exception Value: 'list' object has no attribute 'get'

So I had a closer look on what want wrong,

Exception Value: 'list' object has no attribute 'get'
File "/usr/local/lib/python3.4/dist-packages/django/forms/widgets.py" in value_from_datadict

228. return data.get(name, None)

using some print:

        print("data : %s " % data)
        print("name : %s " % name)

Here is what I got:

data : [{'prix_ligne': 4.75, 'produit': <Produit: Baguette de Boulangerie Bêle >, 'prix_unitaire': 0.95, 'cuisson': [<CuissonDispo: Pas trop cuit>, <CuissonDispo: Standard>, <CuissonDispo: Bien cuit>], 'quantite': 5}] 
name : form-TOTAL_FORMS

So we are trying to do a "get" on object data which is a list... Here is the reason.

So,

Is there something very wrong about my initialization ?
Is there a nasty bug is my particular case ?

Regards.

[Baptiste Mispelon]

Hi,

Shouldn't formset = LigneProduitFormSet2(initial) be formset = LigneProduitFormSet2(initial=initial) instead?

[Drife59]

Yes you are right.

I guess I need more coffee.

Thank you for your help.