PaymentExpress package for django-oscar

This package provides integration with the payment gateway, PaymentExpress using their PX POST API. It is designed to work seamlessly with the e-commerce framework django-oscar but can be used without it.

Installation

From PyPi:

pip install django-oscar-paymentexpress

or from Github:

pip install git+git://github.com/tangentlabs/django-oscar-paymentexpress.git#egg=django-oscar-paymentexpress

Add 'paymentexpress' to INSTALLED_APPS and run:

./manage.py migrate paymentexpress

to create the appropriate database tables.

Configuration

Edit your settings.py to set the following settings:

PAYMENTEXPRESS_POST_URL = 'https://sec.paymentexpress.com/pxpost.aspx'
PAYMENTEXPRESS_USERNAME = '…'
PAYMENTEXPRESS_PASSWORD = '…'
PAYMENTEXPRESS_CURRENCY = 'AUD'

Integration into checkout

You'll need to use a subclass of oscar.apps.checkout.views.PaymentDetailsView within your own checkout views. See oscar's documentation on how to create a local version of the checkout app.

Override the handle_payment method (which is blank by default) and add your integration code. An example integration might look like:

# myshop.checkout.views
from django.conf import settings

from oscar.apps.checkout.views import PaymentDetailsView as OscarPaymentDetailsView
from oscar.apps.payment.forms import BankcardForm
from paymentexpress.facade import Facade
from paymentexpress import PAYMENTEXPRESS

...

class PaymentDetailsView(OscarPaymentDetailsView):

    def get_context_data(self, **kwargs):
        ...
        ctx['bankcard_form'] = BankcardForm()
        ...
        return ctx

    def post(self, request, *args, **kwargs):
        """
        This method is designed to be overridden by subclasses which will
        validate the forms from the payment details page.  If the forms are valid
        then the method can call submit()
        """
        # Check bankcard form is valid
        bankcard_form = BankcardForm(request.POST)
        if not bankcard_form.is_valid():
            ctx = self.get_context_data(**kwargs)
            ctx['bankcard_form'] = bankcard_form
            return self.render_to_response(ctx)

        bankcard = bankcard_form.get_bankcard_obj()

        # Call oscar's submit method, passing through the bankcard object so it gets
        # passed to the 'handle_payment' method
        return self.submit(request.basket, payment_kwargs={'bankcard': bankcard})

    def handle_payment(self, order_number, total, **kwargs):
        # Make request to PaymentExpress - if there any problems (eg bankcard
        # not valid / request refused by bank) then an exception would be
        # raised and handled) within oscar's PaymentDetails view.
        bankcard = kwargs['bankcard']
        response_dict = Facade().purchase(order_number, total, None, bankcard)

        source_type, _ = SourceType.objects.get_or_create(name=PAYMENTEXPRESS)
        source = Source(source_type=source_type,
                        currency=settings.PAYMENTEXPRESS_CURRENCY,
                        amount_allocated=total,
                        amount_debited=total,
                        reference=response_dict['partner_reference'])

        self.add_payment_source(source)

        # Also record payment event
        self.add_payment_event(PURCHASE, total)

Oscar's view will handle the various exceptions that can get raised.

Package structure

There are two key components:

Gateway

The class paymentexpress.gateway.Gateway provides fine-grained access to the PaymentExpress API, which involve constructing XML requests and decoding XML responses. All calls return a paymentexpress.gateway.Response instance which provides dictionary-like access to the attributes of the response.

Example calls:

# Authorise a transaction.
# The funds are not transferred from the cardholder account.
response = gateway.authorise(card_holder='John Smith',
                             card_number='4500230021616301',
                             cvc2='123',
                             amount=50.23)

# Completes (settles) a pre-approved Auth Transaction.
response = gateway.complete(amount=50.23,
                            dps_txn_ref='0000000809b61753')


# Purchase on a new card - funds are transferred immediately
response = gateway.purchase(card_holder='Frankie',
                            card_number=CARD_VISA,
                            card_expiry='1015',
                            cvc2='123',
                            merchant_ref='100001_PURCHASE_1_2008',
                            enable_add_bill_card=1,
                            amount=29.95)

# Purchase on a previously used card
response = gateway.purchase(amount=29.95,
                            billing_id='0000080023748351')


# Refund a transaction - funds are transferred immediately
response = gateway.refund(dps_txn_ref='0000000809b61753',
                          merchant_ref='abc123',
                          amount=50.23)

Facade

The class paymentexpress.facade.Facade wraps the above gateway object and provides a less granular API, as well as saving instances of paymentexpress.models.OrderTransaction to provide an audit trail for PaymentExpress activity.

Settings

• PAYMENTEXPRESS_POST_URL - PX POST URL
• PAYMENTEXPRESS_USERNAME - Username
• PAYMENTEXPRESS_PASSWORD - Password
• PAYMENTEXPRESS_CURRENCY - Currency to use for transactions

Contributing

To work on django-oscar-paymentexpress, clone the repo, set up a virtualenv and install in develop mode:

python setup.py develop

then install the testing dependencies:

pip install -r requirements.txt

The test suite can then be run using:

./run_tests.py

Magic card numbers are available on the PaymentExpress site: http://www.paymentexpress.com/knowledge_base/faq/developer_faq.html#Testing%20Details

Sample VISA vard:

4111111111111111