Django Oscar CCH

This package is to handle integration between django-oscar based e-commerce sites and the CCH Sales Tax Office SOAP API.

Caveats

1. You must fork the order application from Oscar to enable tax calculation as part of placing an order.
2. Persistence of tax details, while optional, requires that your project uses PostgreSQL. It relies on the HStore field.

Installation

1. Install the instrumented-soap and django-oscar-cch packages.:

   $ pip install git+https://gitlab.com/thelabnyc/instrumented-soap.git#r1.0.0
   $ pip install git+https://gitlab.com/thelabnyc/django-oscar-cch.git#r1.0.0
   

2. Add cch to your INSTALLED_APPS:

   # myproject/settings.py
   ...
   INSTALLED_APPS = [
       'django.contrib.admin',
       'django.contrib.auth',
       'django.contrib.contenttypes',
       'django.contrib.sessions',
       'django.contrib.sites',
       'django.contrib.postgres',
       ...
       'cch',
       ...
   ] + get_core_apps([
       ...
   ])
   ...
   

3. Add some attributes to settings.py to configure how the application should connect to CCH.:

   # myproject/settings.py
   
   # Add this is you need to connect to the SOAP API through an HTTP Proxy
   SOAP_PROXY_URL = ...
   
   # Configure the CCH WSDL location, entity, and division code
   CCH_WSDL = ...
   CCH_ENTITY = ...
   CCH_DIVISION = ...
   
   # Provide either a product SKU or a product group and item to send to CCH when calculating taxes
   CCH_PRODUCT_SKU = ...
   CCH_PRODUCT_GROUP = ...
   CCH_PRODUCT_ITEM = ...
   

4. Alternative to setting CCH_PRODUCT_SKU, CCH_PRODUCT_GROUP, and CCH_PRODUCT_ITEM globally, you can set them per-product by creating ProductClass attributes with the same names (in lowercase).

5. Install extra fields on order.models.Order and order.models.Line (see also How to fork Oscar apps).:

   # order/models.py
   
   from cch.mixins import CCHOrderMixin, CCHOrderLineMixin
   from oscar.apps.order.abstract_models import AbstractOrder, AbstractLine
   
   class Order(CCHOrderMixin, AbstractOrder):
       pass
   
   class Line(CCHOrderLineMixin, AbstractLine):
       pass
   
   from oscar.apps.order.models import *  # noqa
   

6. Create and run migrations for the order app.:

   $ python manage.py makemigrations order
   $ python manage.py migrate
   

7. Add the CCH mixin to order.utils.OrderCreator.:

   # order/utils.py
   
   from cch.mixins import CCHOrderCreatorMixin
   from oscar.apps.order import utils
   
   
   class OrderCreator(CCHOrderCreatorMixin, utils.OrderCreator):
       pass
   

Usage

CCHTaxCalculator is used to apply taxes to a user's basket.:

from cch.calculator import CCHTaxCalculator
from cch.models import OrderTaxation


# Take a basket and the customer's shipping address and apply taxes to the basket. We can optionally
# tolerate a failure to connect to the CCH server. In such a case, tax will be set to 0 and the method
# will return none. In normal cases, the method will return the details of the taxes applied.
cch_response = CCHTaxCalculator().apply_taxes(basket, shipping_address, ignore_cch_fail=True)
is_tax_known = (cch_response is not None)

# ...
# Do other things necessary to convert the basket into an order
# ...

# Take the tax details generated earlier and save them into the DB.
if is_tax_known:
    OrderTaxation.save_details(order, cch_response)

The apply_taxes method always sends a SOAP request to CCH. Is cases where you want to cache this call, for example, when exposing this functionality via an HTTP API, you can use the estimate_taxes method instead.:

from cch.calculator import CCHTaxCalculator

# This method returns a (sometimes hydrated from cache) basket with taxes applied. The cache is invalidated
# automatically whenever a the basket or one of it's lines is saved. See cch.handlers for details.
basket = CCHTaxCalculator().estimate_taxes(basket, shipping_address)

Changelog

1.1.1

• Fix bug where calculator could throw exception even when ignore_cch_error flag was set.

1.1.0

• Add the ability to set CCH product SKU, item, and group per-product in addition to globally.

1.0.5

• Add CCH_TIME_ZONE setting.
• Send time zone aware ISO format date as CalculateRequest InvoiceDate node. Formerly just sent the date.

1.0.4

• Truncate ZIP coes so that CCH doesn't choke when the user supplies a full 9-digit ZIP code.

1.0.3

• Improve unit tests by mocking all requests and responses. This allows running tests without a connection to an actual CCH server instance.
• Fixed bug where floats from SOAP response weren't properly converted into quantized decimals when saving OrderTaxation and LineTaxation models.

1.0.2

• Made instrumented-soap dependency optional.
• Moved gitlab testing from the shell executor to the docker executor.
• Added better usage documentation.

1.0.1

• Fixed an exception when raven isn't installed.

1.0.0

• Initial release.