Saving a form collection with related models

[omarcoming]

I'm having trouble getting my form collection to save. I have 3 models I'm working with: Contacts, Line, and Payment where Line has a foreign key to Payment and Payment has a foreign key to Contacts. LineCollection is implemented with siblings to add additional rows. I've created a form collection for Line (contains LineForm) and Payment (contains LineCollection and PaymentForm). InvoiceCollection contains PaymentCollection and ContactCollection. However in order to simplify the problem and isolate the issue I didn't implement Contacts yet. I've been following the documentation, studying the test app, and searching through github but I am stumped.

This is the error I get:
Unprocessable Entity: /invoice/add/ [30/May/2024 19:36:24] "POST /invoice/add/ HTTP/1.1" 422 126

Exploring this further I see:
{'lines': {'__all__': ['Form data is missing.']}, 'payment': {'__all__': ['Form data is missing.']}}

First thing I can't figure out is the data variable in retrieve_instance function in my parent collection (PaymentCollection), is a list that only contains the child collection (LineCollection). So I changed the function so that I'm setting data to self.data.get('payment') and I'm able to return an instance of Payment.

The other thing I noticed is the payment and id fields are empty strings. If I understand correctly, retrieve_instance is meant to point payment to a Payment object. Does the id field only update if you add additional siblings?

Since this didn't work I tried removing ContactCollection from InvoiceCollection but I still get the same error.

I will include the relevant code.

models.py

class Line(models.Model):
    class Material(models.TextChoices):
        NATURAL_QUARTZITE = 'NATURAL QUARTZITE', 'Natural Quartzite'
        ENGINEERED_QUARTZ = 'ENGINEERED QUARTZ', 'Engineered Quartz'
        GRANITE = 'GRANITE', 'Granite'
        MARBLE = 'MARBLE', 'Marble'
        DOLOMITE = 'DOLOMITE', 'Dolomite'
        SOAPSTONE = 'SOAPSTONE', 'Soapstone'
        OTHER = 'OTHER', 'Other'

    class Vendor(models.TextChoices):
        QARTS = 'Q-ARTS'
        MARBOLIS = 'MARBOLIS'
        SLABSTUDIO = 'SLABSTUDIO'
        WALKERZENGER = 'WALKERZENGER'
        OTHER = 'OTHER'

    class Finish(models.TextChoices):
        POLISHED = 'POLISHED'
        HONED = 'HONED'
        MATTE = 'MATTE'
        LEATHERED = 'LEATHERED'
        SATIN = 'SATIN'
        OTHER = 'OTHER'

    product = models.CharField('Product', max_length=25)
    material = models.CharField('Material', max_length=25, choices=Material.choices, blank=True)
    vendor = models.CharField('Vendor', max_length=25, blank=True)
    unit = models.CharField('Unit', default='ea', max_length=3)
    qty = models.IntegerField('Qty', default=0)
    price = models.DecimalField('Price', default=0, decimal_places=2, max_digits=9)
    prod_total = models.DecimalField('Line Total', default=0, decimal_places=2, max_digits=9)
    block = models.CharField('Block #', max_length=15, null=True, blank=True)
    length = models.DecimalField('Length', default=0, decimal_places=2, max_digits=5, null=True, blank=True)
    width = models.DecimalField('Width', default=0, decimal_places=2, max_digits=5, null=True, blank=True)
    payment = models.ForeignKey('Payment', on_delete=models.CASCADE, null=True, blank=True, related_name='lines')
    date_created = models.DateTimeField(auto_now_add=True, null=True, blank=True)

    class Meta:
        verbose_name = 'Line'
        verbose_name_plural = 'Lines'
        unique_together = ['date_created', 'payment']

class Payment(models.Model):
    class Status(models.TextChoices):
        BALANCE = 'BALANCE'
        PAID = 'PAID'
        CREDIT = 'CREDIT'

    class PaymentType(models.TextChoices):
        CASH = 'CASH'
        CHECK = 'CHECK'
        CARD = 'CARD'

    date_created = models.DateTimeField(auto_now_add=True, null=True, blank=True)

    payment_type = models.CharField('Payment Method', max_length=20, blank=True, choices=PaymentType.choices)
    deposit = models.DecimalField('Deposit', decimal_places=2, max_digits=9, default=0)
    subtotal = models.DecimalField('Subtotal', decimal_places=2, max_digits=9, default=0)
    payment_status = models.CharField('Payment Status', max_length=10, blank=True, choices=Status.choices)
    balance = models.DecimalField('Balance', decimal_places=2, max_digits=9, default=0)
    tax = models.DecimalField('Sales Tax', decimal_places=2, max_digits=9, default=0)
    invoice_notes = models.TextField('Notes', blank=True)
    total = models.DecimalField('Total', decimal_places=2, max_digits=9, default=0)
    contact = models.ForeignKey(Contact, on_delete=models.CASCADE, null=True, blank=True, related_name='payments')

    class Meta:
        verbose_name = 'Payment'
        verbose_name_plural = 'Payments'

    def __str__(self):
        return str(self.id)

    def calculate_tax(self, tax_rate=.0775):
        return self.subtotal * tax_rate`


forms.py
class LineForm(ModelForm):
    id = forms.IntegerField(required=False, widget=forms.HiddenInput)
    default_renderer = FormRenderer(
        form_css_classes='row border p-1 m-1',
        field_css_classes={
            'unit': 'mb-1 col-1 mx-0',
            'qty': 'mb-1 col-1 mx-0',
            'product': 'mb-1 col-2 mx-0',
            'material': 'mb-1 col-1 mx-0',
            'vendor': 'mb-1 col-2 mx-0',
            'price': 'mb-1 col-1 mx-0',
            'prod_total': 'mb-1 col-1 mx-0',
            'block': 'mb-1 col-1 mx-0',
            'length': 'mb-1 col-1 mx-0',
            'width': 'mb-1 col-1 mx-0',
        }
    )

    class Meta:
        model = Line
        fields = [
            'payment',
            # 'date_created',
            'unit',
            'qty',
            'product',
            'material',
            'vendor',
            'block',
            'length',
            'width',
            'price',
            'prod_total',
            'id',
        ]
        widgets = {
            'payment': forms.HiddenInput(attrs={
                'class': 'form-control',
                'id': 'payment',
            }),
            'unit': forms.TextInput(attrs={
                'class': 'form-control',
                'id': 'unit',
            }),
            'qty': forms.NumberInput(attrs={
                'class': 'form-control product-input qty-product',
                'id': 'qty',
                'type': 'number',
                'oninput': 'calculateProductTotal()'
            }),
            'price': forms.NumberInput(attrs={
                'class': 'form-control product-input price-product',
                'id': 'product_price',
                'type': 'number',
                'oninput': 'calculateProductTotal()',
                'onblur': 'addDecimal()',
            }),
            'prod_total': forms.NumberInput(attrs={
                'class': 'form-control product-input total-product',
                'id': 'product_total',
                'type': 'number',
                'readonly': 'True',
            }),
            'block': forms.TextInput(attrs={
                'class': 'form-control product-input',
                'id': 'block',
            }),
            'length': forms.NumberInput(attrs={
                'class': 'form-control product-input',
                'id': 'length',
                'type': 'number',
            }),
            'width': forms.NumberInput(attrs={
                'class': 'form-control product-input',
                'id': 'width',
                'type': 'number',
            }),
            'product': forms.TextInput(attrs={
                # 'class': 'form-control product-input mb-1 col-3',
                'class': 'form-control',
                'id': 'product',
            }),
            'material': forms.Select(attrs={
                # 'class': 'form-control product-input mb-1 col-2',
                'class': 'form-control',
                'id': 'material',
            }),
            'vendor': forms.TextInput(attrs={
                'class': 'form-control',
                'id': 'vendor',
                'value': 'Q-ARTS',
            }),

        }

        def model_to_dict(self, payment):
            try:
                return model_to_dict(payment.line, fields=self._meta.fields, exclude=self._metal.exclude)
            except Line.DoesNotExist:
                return {}

        def construct_instance(self, payment):
            try:
                line = payment.line
            except Line.DoesNotExist:
                line = Line(payment=payment)
            form = LineForm(data=self.cleaned_data, instance=line)
            if form.is_valid():
                construct_instance(form, line)
                form.save()



class LineCollection(FormCollection):
    min_siblings = 1
    line = LineForm()
    legend = 'LINE ITEMS:'
    add_label = 'Add line'
    related_field = 'payment'

    def retrieve_instance(self, data):
        if data := data.get('line'):
            try:
                return self.instance.lines.get(id=data.get('id') or 0)
            except(AttributeError, Product.DoesNotExist, ValueError):
                return Line(
                    payment=self.instance,
                    unit=data.get('unit'),
                    qty=data.get('qty'),
                    product=data.get('product'),
                    material=data.get('material'),
                    vendor=data.get('vendor'),
                    block=data.get('block'),
                    length=data.get('length'),
                    width=data.get('width'),
                    price=data.get('price'),
                    prod_total=data.get('prod_total'),
                    id=data.get('id') or 0,
                )


class PaymentForm(ModelForm):
    default_renderer = FormRenderer(
        form_css_classes='row',
        field_css_classes={'*': 'mb-1 col-4',
                           'invoice_notes': 'mb-1 col-8'}
    )

    class Meta:
        model = Payment
        fields = [
            'payment_type',
            'deposit',
            'subtotal',
            'payment_status',
            'balance',
            'tax',
            'invoice_notes',
            'total',
            'contact',
        ]
        exclude = ['contact']
        widgets = {
            'payment_type': forms.Select(attrs={
                'class': 'form-control',
                'id': 'payment_type',
                'placeholder': 'Check',
            }),
            'payment_status': forms.Select(attrs={
                'class': 'form-control',
                'id': 'payment_status',
                'placeholder': 'PAID',
            }),
            'subtotal': forms.NumberInput(attrs={
                'class': 'form-control',
                'id': 'subtotal',
                'placeholder': '0.00',
                'type': 'number',
                'readonly': 'True',
            }),
            'tax': forms.NumberInput(attrs={
                'class': 'form-control',
                'id': 'tax',
                'type': 'number',
                'readonly': 'True'
            }),
            'total': forms.NumberInput(attrs={
                'class': 'form-control',
                'id': 'total',
                'placeholder': '0.00',
                'type': 'number',
                'readonly': 'True',
            }),
            'deposit': forms.NumberInput(attrs={
                'class': 'form-control',
                'id': 'deposit',
                'default': '0.00',
                'type': 'number',
                'oninput': 'calculateBalance()',
                'step': '0.01',
                'onblur': 'addDecimalToDeposit()',
            }),
            'balance': forms.NumberInput(attrs={
                'class': 'form-control',
                'id': 'balance',
                'placeholder': '0.00',
                'type': 'number',
                'readonly': 'True'
            }),
            'invoice_notes': forms.Textarea(attrs={
                'class': 'form-control',
                'id': 'invoice_notes',
                'placeholder': 'Enter notes',
                'rows': '1'
            }),
        }


class PaymentCollection(FormCollection):
    lines = LineCollection()
    payment = PaymentForm()
    # related_field = 'contact'

    def retrieve_instance(self, data):
        if data := self.data.get('payment'):
            return Payment(
                payment_type=data.get('payment_type'),
                deposit=data.get('deposit'),
                subtotal=data.get('subtotal'),
                payment_status=data.get('payment_status'),
                balance=data.get('balance'),
                tax=data.get('tax'),
                invoice_notes=data.get('invoice_notes'),
                total=data.get('total'),
                # contact=self.instance,
            )


class InvoiceCollection(FormCollection):
    payment = PaymentCollection()



views.py

class EditView(UpdateView, FormViewMixin):
    def get_object(self, queryset=None):
        if queryset is None:
            queryset = self.get_queryset()
            if self.kwargs:
                return queryset.get(pk=self.kwargs['pk'])

    def get_success_url(self):
        model = self.model._meta.model_name
        if pk := self.object.id:
            return reverse(f'{model}-edit', kwargs={'pk': pk})
        else:
            return reverse(f'{model}-list')

    def get_context_data(self, **kwargs):
        context_data = super().get_context_data(**kwargs)
        if self.object:
            context_data['change'] = True
        else:
            context_data['add'] = True
        return context_data

    def form_valid(self, form):
        if extra_data := self.get_extra_data():
            if extra_data.get('add') is True:
                form.instance.save()
            if extra_data.get('delete') is True:
                form.instance.delete()
                response_data = {'success_url': force_str(self.get_success_url())}
                return JsonResponse(response_data)
        return super().form_valid(form)

class LineListView(TotalsListView):
    model = Line
    template_name = 'invoice/line-list.html'


class LineEditView(EditView):
    model = Line
    template_name = 'invoice/line.html'
    form_class = LineForm
    extra_context = None


class LineCollectionView(EditCollectionView):
    model = Line
    collection_class = LineCollection
    template_name = 'invoice/line.html'


class PaymentListView(TotalsListView):
    model = Payment
    template_name = 'invoice/payment-list.html'


class PaymentEditView(EditView):
    model = Payment
    template_name = 'invoice/payment.html'
    form_class = PaymentForm
    extra_context = None



class PaymentCollectionView(EditCollectionView):
    model = Payment
    collection_class = PaymentCollection
    template_name = 'invoice/payment-collection.html'

    def get_object(self, queryset=None):
        if queryset is None:
            queryset = self.get_queryset()
            if self.kwargs:
                return queryset.get(pk=self.kwargs['pk'])


class InvoiceCollectionView(FormCollectionView):
    collection_class = InvoiceCollection
    template_name = 'invoice/invoice-collection.html'

[jrief]

without going too much into your details (didn't try to get your code up and running), did you have a look at the example 'CompaniesCollection'. For me, your use-case looks very similar to that example.

[omarcoming]

Yes I have been. I did spot one error, I was setting the ID attribute in retrieve_instance() so I removed that. I also had implemented model_to_dict() and construct_instance() in case that was the issue but removed that as well.

Now I'm not getting any errors and get a POST 200 21 code but nothing is saving to the database. My debugger is skipping over form_collection_valid() in EditCollectionView but the cleaned_data looks good in the post() function in FormCollectionViewMixin.

In my debugger I am getting an error saying self.contact and self.invoice is not defined. I thought maybe I needed to create an Invoice model with a foreign key to Contact and with Payment having a OneToOne relation to Invoice. Is this possible? I'm trying to implement it but I'm getting an error because my Invoice form is empty