Set the Selected Value of ChoiceField when using a FormView

Question

I'm displaying a form using a FormView, but I need to set a selected ChoiceField when page renders, e.g. set a default selection.

Acoording to a related Question, I need to:

Try setting the initial value when you instantiate the form:

I don't know how to do it. I've also tried seeting initial=1 without success

class StepOneForm(forms.Form):
    size = forms.ChoiceField(choices=TAMANIOS, widget=forms.RadioSelect(), label='Selecciona un tamaño', initial=1)
    quantity = forms.ChoiceField(choices=CANTIDADES, widget=forms.RadioSelect(), label='Selecciona la cantidad')

forms.py

class StepOneForm(forms.Form):
    size = forms.ChoiceField(choices=TAMANIOS, widget=forms.RadioSelect(), label='Selecciona un tamaño')
    quantity = forms.ChoiceField(choices=CANTIDADES, widget=forms.RadioSelect(), label='Selecciona la cantidad')


class StepTwoForm(forms.ModelForm):
    comment = forms.CharField(widget=forms.Textarea)

    class Meta:
        model = CartItem
        fields = ('file', 'comment')

    def __init__(self, *args, **kwargs):
        super(StepTwoForm, self).__init__(*args, **kwargs)
        self.fields['comment'].required = False
        self.fields['file'].required = False

    def save(self, commit=True):
        instance = super(StepTwoForm, self).save(commit=commit)
        return instance

views.py

class StepOneView(FormView):
    form_class = StepOneForm
    template_name = 'shop/medidas-cantidades.html'
    success_url = 'subir-arte'

    def get_initial(self):
        # pre-populate form if someone goes back and forth between forms
        initial = super(StepOneView, self).get_initial()
        initial['size'] = self.request.session.get('size', None)
        initial['quantity'] = self.request.session.get('quantity', None)
        initial['product'] = Product.objects.get(
            category__slug=self.kwargs['c_slug'],
            slug=self.kwargs['product_slug']
        )

        return initial

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['product'] = Product.objects.get(
            category__slug=self.kwargs['c_slug'],
            slug=self.kwargs['product_slug']
        )
        return context

    def form_invalid(self, form):
        print('Step one: form is NOT valid')

    def form_valid(self, form):
        cart_id = self.request.COOKIES.get('cart_id')
        if not cart_id:
            cart = Cart.objects.create(cart_id="Random")
            cart_id = cart.id
        cart = Cart.objects.get(id=cart_id)
        item = CartItem.objects.create(
            size=form.cleaned_data.get('size'),
            quantity=form.cleaned_data.get('quantity'),
            product=Product.objects.get(
                category__slug=self.kwargs['c_slug'],
                slug=self.kwargs['product_slug']
            ),
            cart=cart
        )

        response = HttpResponseRedirect(self.get_success_url())
        response.set_cookie("cart_id", cart_id)
        response.set_cookie("item_id", item.id)
        return response


# here we are going to use CreateView to save the Third step ModelForm
class StepTwoView(FormView):
    form_class = StepTwoForm
    template_name = 'shop/subir-arte.html'
    success_url = '/cart/'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['product'] = Product.objects.get(
            category__slug=self.kwargs['c_slug'],
            slug=self.kwargs['product_slug']
        )
        return context

    def form_invalid(self, form):
        print('StepTwoForm is not Valid', form.errors)

    def form_valid(self, form):
        item_id = self.request.COOKIES.get("item_id")

        cart_item = CartItem.objects.get(id=item_id)
        cart_item.file = form.cleaned_data["file"]
        cart_item.comment = form.cleaned_data["comment"]
        cart_item.step_two_complete = True
        cart_item.save()
        response = HttpResponseRedirect(self.get_success_url())
        response.delete_cookie("item_id")
        return response

UPDATE 1:

TAMANIOS = (('5cm x 5cm', '5 cm x 5 cm',), ('7cm x 7cm', '7 cm x 7 cm',),
            ('10cm x 10cm', '10 cm x 10 cm',), ('13cm x 13cm', '13 cm x 13 cm',))    
CANTIDADES = (('50', '50',), ('100', '100',),
              ('200', '200',), ('300', '300',),
              ('500', '500',), ('1000', '1000',),
              ('2000', '2000',), ('3000', '3000',),
              ('4000', '4000',), ('5000', '5000',),
              ('10000', '10000',))

Can you share the **TAMANIOS** choices so we can take a look at how it was built? — Bernardo Duarte, Feb 09 '19 at 20:28
I've posted an answer, I believe it solves your issue, see it below! — Bernardo Duarte, Feb 11 '19 at 11:54

score 0 · Answer 1 · answered Feb 10 '19 at 20:43

You're thinking about setting the first choice value to be the default value, to do it you need to set the initial value equal to the value you want.

From Django's choices interface, each choice is a tuple with the following format: (value, representation).

So to set the value you want as the initial one you need to pick the first index of the choice, from your TAMANIOS choices the first one is ('5cm x 5cm', '5 cm x 5 cm',), so the initial value should be: '5cm x 5cm'.

An example is shown bellow, with a picture of it's result.

class StepOneForm(forms.Form):
    size = forms.ChoiceField(choices=TAMANIOS, widget=forms.RadioSelect(), label='Selecciona un tamaño', initial='5cm x 5cm')
    quantity = forms.ChoiceField(choices=CANTIDADES, widget=forms.RadioSelect(), label='Selecciona la cantidad')

Set the Selected Value of ChoiceField when using a FormView

1 Answers1