@classmethod

    def set_fields(cls, category, products):

        for product in products:

            if product.description:

                help_text = "$%d each -- %s" % (product.price, product.description)

            else:

                help_text = "$%d each" % product.price

            field = forms.IntegerField(

                label=product.name,

                help_text=help_text,

            )

            cls.base_fields[cls.field_name(product)] = field

    @classmethod

    def initial_data(cls, product_quantities):

        initial = {}

        for product, quantity in product_quantities:

            initial[cls.field_name(product)] = quantity

        return initial

    def product_quantities(self):