def disable_product(self, product):

            ''' Removes a given product from this form. '''

            del self.fields[field_name(product)]

        def disable_products_for_user(self, user):

            for product in products:

                # Remove fields that do not have an enabling condition.

                prod = ProductController(product)

                if not prod.can_add_with_enabling_conditions(user, 0):

                    self.disable_product(product)

    products = rego.Product.objects.filter(category=category).order_by("order")

    for product in products:

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

        field = forms.IntegerField(

            label=product.name,

            help_text=help_text,

        )

        _CategoryForm.base_fields[field_name(product)] = field

    return _CategoryForm

from registrasion import models as rego

from django import template

register = template.Library()

@register.assignment_tag(takes_context=True)

def available_categories(context):

    ''' Returns all of the available product categories '''

    return rego.Category.objects.all()

        discount_items = list(cart.cart.discountitem_set.all())

        # There is one discount, and it should apply to the more expensive.

        self.assertEqual(1, len(discount_items))

        self.assertEqual(self.PROD_3, discount_items[0].product)

    def test_discount_quantity_is_per_user(self):

        self.add_discount_prod_1_includes_cat_2(quantity=1)

        # Both users should be able to apply the same discount

        # in the same way

        for user in (self.USER_1, self.USER_2):

            cart = CartController.for_user(user)

            cart.add_to_cart(self.PROD_3, 1)

            discount_items = list(cart.cart.discountitem_set.all())

            # The discount is applied.

            self.assertEqual(1, len(discount_items))

            product=self.PROD_1,

            percentage=Decimal(100),

            quantity=1

        ).save()

        # Having PROD_1 in place should add a discount

        current_cart = CartController.for_user(self.USER_1)

        current_cart.apply_voucher(voucher.code)

        current_cart.add_to_cart(self.PROD_1, 1)

        self.assertEqual(1, len(current_cart.cart.discountitem_set.all()))

    def test_voucher_codes_unique(self):

        with self.assertRaises(IntegrityError):

    def test_multiple_vouchers_work(self):

    def test_vouchers_case_insensitive(self):

        voucher = self.new_voucher(code="VOUCHeR")

        current_cart = CartController.for_user(self.USER_1)

        current_cart.apply_voucher(voucher.code.lower())

from django.conf.urls import url, patterns

urlpatterns = patterns(

    "registrasion.views",

    url(r"^category/([0-9]+)$", "product_category", name="product_category"),

    url(r"^checkout$", "checkout", name="checkout"),

    url(r"^invoice/([0-9]+)$", "invoice", name="invoice"),

    url(r"^invoice/([0-9]+)/pay$", "pay_invoice", name="pay_invoice"),

    url(r"^profile$", "edit_profile", name="profile"),

    url(r"^register$", "guided_registration", name="guided_registration"),

)

from registrasion import forms

from registrasion import models as rego

from registrasion.controllers.cart import CartController

from registrasion.controllers.invoice import InvoiceController

from django.contrib.auth.decorators import login_required

from django.core.exceptions import ObjectDoesNotExist

from django.core.exceptions import ValidationError

from django.db import transaction

from django.shortcuts import redirect

from django.shortcuts import render

@login_required

def guided_registration(request, page_id=0):

    ''' Goes through the registration process in order,

    form = forms.ProfileForm(request.POST or None, instance=profile)

    if request.POST and form.is_valid():

        form.instance.attendee = attendee

        form.save()

    data = {

        "form": form,

    }

    return render(request, "profile_form.html", data)

@login_required

def product_category(request, category_id):

    ''' Registration selections form for a specific category of items.

    '''

    PRODUCTS_FORM_PREFIX = "products"

    VOUCHERS_FORM_PREFIX = "vouchers"

    category_id = int(category_id)  # Routing is [0-9]+

    category = rego.Category.objects.get(pk=category_id)

    current_cart = CartController.for_user(request.user)

    CategoryForm = forms.CategoryForm(category)

    attendee = rego.Attendee.get_instance(request.user)

    products = rego.Product.objects.filter(category=category)

    products = products.order_by("order")

    if request.method == "POST":

        cat_form.disable_products_for_user(request.user)

            # Apply voucher

            # leave

            voucher = voucher_form.cleaned_data["voucher"]

            try:

                current_cart.apply_voucher(voucher)

            except Exception as e:

                voucher_form.add_error("voucher", e)

            # Re-visit current page.

        elif cat_form.is_valid():

            try:

                handle_valid_cat_form(cat_form, current_cart)

                pass

            # If category is required, the user must have at least one

            # in an active+valid cart

            if category.required:

                carts = rego.Cart.reserved_carts()

                carts = carts.filter(user=request.user)

                items = rego.ProductItem.objects.filter(

                    product__category=category,

                    cart=carts,

                )

                    attendee.save()

                return redirect("dashboard")

    else:

        # Create initial data for each of products in category

        items = rego.ProductItem.objects.filter(

            product__category=category,

            cart=current_cart.cart,

        )

        quantities = []

        for product in products:

            # Only add items that are enabled.

            try:

                quantity = items.get(product=product).quantity

            except ObjectDoesNotExist:

                quantity = 0

            quantities.append((product, quantity))

        initial = CategoryForm.initial_data(quantities)

        cat_form = CategoryForm(prefix=PRODUCTS_FORM_PREFIX, initial=initial)

        cat_form.disable_products_for_user(request.user)

        voucher_form = forms.VoucherForm(prefix=VOUCHERS_FORM_PREFIX)

    data = {

        "category": category,

        "form": cat_form,

        "voucher_form": voucher_form,

    }

    return render(request, "product_category.html", data)

@transaction.atomic

def handle_valid_cat_form(cat_form, current_cart):

    for product_id, quantity, field_name in cat_form.product_quantities():

        product = rego.Product.objects.get(pk=product_id)

        try:

            current_cart.set_quantity(product, quantity, batched=True)

        except ValidationError as ve:

            cat_form.add_error(field_name, ve)

    if cat_form.errors:

        raise ValidationError("Cannot add that stuff")

    current_cart.end_batch()

@login_required

def checkout(request):

    ''' Runs checkout for the current cart of items, ideally generating an

    invoice. '''

    current_cart = CartController.for_user(request.user)

    current_invoice = InvoiceController.for_cart(current_cart.cart)

    return redirect("invoice", current_invoice.invoice.id)

@login_required

    ''' Displays an invoice for a given invoice id. '''

    invoice_id = int(invoice_id)

    inv = rego.Invoice.objects.get(pk=invoice_id)

    current_invoice = InvoiceController(inv)

    data = {

        "invoice": current_invoice.invoice,

    }

    return render(request, "invoice.html", data)

@login_required

def pay_invoice(request, invoice_id):

    ''' Marks the invoice with the given invoice id as paid.

    WORK IN PROGRESS FUNCTION. Must be replaced with real payment workflow.

    '''

    invoice_id = int(invoice_id)

    inv = rego.Invoice.objects.get(pk=invoice_id)

    current_invoice = InvoiceController(inv)

    if not inv.paid and current_invoice.is_valid():

        current_invoice.pay("Demo invoice payment", inv.value)