satchless model example

forms.py

from django import forms
from satchless.forms.widgets import DecimalInput
from satchless.product.forms import BaseVariantForm

from . import models

class ProductPriceForm(forms.ModelForm):
    class Meta:
        widgets = {
            'price': DecimalInput(min_decimal_places=2),
        }

class ShoeVariantForm(BaseVariantForm):
    color = forms.CharField(
            max_length=10,
            widget=forms.Select(choices=models.ShoeVariant.COLOR_CHOICES))
    size = forms.CharField(
            max_length=6,
            widget=forms.Select(choices=models.ShoeVariant.SIZE_CHOICES))

    def __init__(self, *args, **kwargs):
        super(ShoeVariantForm, self).__init__(*args, **kwargs)
        used_colors = self.product.variants.values_list('color', flat=True).distinct()
        color_choices = [(k, v)
                         for k, v in models.ShoeVariant.COLOR_CHOICES
                         if k in used_colors]
        self.fields['color'].choices = color_choices
        used_sizes = self.product.variants.values_list('size', flat=True).distinct()
        size_choices = [(k, v)
                        for k, v in models.ShoeVariant.SIZE_CHOICES
                        if k in used_sizes]
        self.fields['size'].choices = size_choices

    def _get_variant_queryset(self):
        return models.ShoeVariant.objects.filter(
            product=self.product,
            color=self.cleaned_data['color'],
            size=self.cleaned_data['size'],
        )

    def clean(self):
        if not self._get_variant_queryset().exists():
            raise forms.ValidationError("We are sorry but we don't carry this"
                                        " particular color and size combination")
        return self.cleaned_data

    def get_variant(self):
        return self._get_variant_queryset().get()