/django-getpaid

Django payments processor.

Primary LanguagePythonMIT LicenseMIT

Welcome to django-getpaid

Latest PyPI version

django-getpaid is a multi-broker payment processor for Django

Documentation

The full documentation is at https://django-getpaid.readthedocs.io.

Quickstart

Install django-getpaid:

pip install django-getpaid

Add it to your INSTALLED_APPS:

INSTALLED_APPS = (
    ...
    'getpaid.apps.GetpaidConfig',
    ...
)

Add django-getpaid's URL patterns:

from getpaid import urls as getpaid_urls


urlpatterns = [
    ...
    url(r'^', include(getpaid_urls)),
    ...
]

Features

  • multiple payment brokers support - allows using simultaneously many payments methods at the same time,
  • multiple payments currency support (getpaid will automatically filter available backends list accordingly to the payment currency),
  • integration flexibility - makes minimal assumption on 3rd party code - requires only an existence of any single django model representing an order,
  • proper architecture design - all backends which requires fetching payment confirmation are enforced to use asynchronous celery tasks.

Supported backends:

In alphabetical order:

Don't see the payment backend you need? Writing your own backend is very simple. Pull requests are welcome.

Payment workflow integration

With few simple steps you will easily integrate your project with django-getpaid. This module is shipped with very well documented django-getpaid test project which can be found with module source code. Please refer to this code for implementation details.

Step 1. Prepare your order model

Required

First of all you need a model that will represent an order in you application. It does not matter how complicated the model is or what fields does it provide, be it single item order, or multiple items order. Let's take an example from test project:

from django.core.urlresolvers import reverse
from django.db import models
import getpaid

class Order(models.Model):
    name = models.CharField(max_length=100)
    total = models.DecimalField(decimal_places=2, max_digits=8, default=0)
    currency = models.CharField(max_length=3, default='EUR')
    status = models.CharField(max_length=1, blank=True, default='W', choices=(('W', 'Waiting for payment'),
                                                                               ('P', 'Payment complete')))
    def get_absolute_url(self):
        return reverse('order_detail', kwargs={'pk': self.pk})

    def __unicode__(self):
        return self.name

Payment = getpaid.register_to_payment(Order, unique=False, related_name='payments')

and add the following line to your settings:

GETPAID_ORDER_MODEL = 'my_super_app.Order'

First of all, class name is not important at all. You register a model with register_to_payment method.

You can add some kwargs that are basically used for ForeignKey kwargs. In this example whe allow creating multiple payments for one order, and naming One-To-Many relation.

There are two important things on that model. In fact two methods are required to be present in order class. The first one is __unicode__ method as this will be used in few places as a fallback for generating order description. The second one is get_absolute_url method which should return an URL of order object. It is used again as a fallback for some final redirections after payment success of failure (if you do not provide otherwise).

The second important thing is, that it actually doesn't matter if you store total in database or just sum it up from some items. You will see why, in further sections.

Step 2. Prepare payment form for order

Required

Your application - after some custom workflow - just created an order object. That's fine. We now want to get paid for that order. So lets take a look on a view for creating a payment for an order:

from django.views.generic.detail import DetailView
from getpaid.forms import PaymentMethodForm
from example.orders.models import Order

class OrderView(DetailView):
    model=Order

    def get_context_data(self, **kwargs):
        context = super(OrderView, self).get_context_data(**kwargs)
        context['payment_form'] = PaymentMethodForm(self.object.currency, initial={'order': self.object})
        return context

Here we get a PaymentMethodForm object, that is parametrised with currency type. This is an important thing, because this form will display you only payments method that are suitable for a given order currency.

PaymentMethodForm provides two fields: HiddenInput with order_id and ChoiceField with backend name. This is how you use it in template:

<form action="{% url 'getpaid:new-payment' currency=object.currency %}" method="post">
    {% csrf_token %}
    {{ payment_form.as_p }}
    <input type="submit" value="Continue">
</form>

Action URL of form should point on named link getpaid:new-payment that requires currency code argument. This form will redirect client from order view directly to page of payment broker.

Step 3. Filling necessary payment data

Required

Because the idea of whole module is that it should be loosely coupled, there is this convention that it does not require any structure of your order model. But still it needs to know some transaction details of your order. Django signals are used for that. django-getpaid, while generating gateway redirect url, will emit a getpaid.signals.new_payment_query signal. Here is the signal declaration:

new_payment_query = Signal(providing_args=['order', 'payment'])
new_payment_query.__doc__ = """
Sent to ask for filling Payment object with additional data:
    payment.amount:                 total amount of an order
    payment.currency:               amount currency
This data cannot be filled by ``getpaid`` because it is Order structure
agnostic. After filling values just return. Saving is done outside signal.
"""

Your code should have some signal listeners, that will fill payment object with required information:

from getpaid import signals

def new_payment_query_listener(sender, order=None, payment=None, **kwargs):
    """
    Here we fill only two obligatory fields of payment, and leave signal handler
    """
    payment.amount = order.total
    payment.currency = order.currency

signals.new_payment_query.connect(new_payment_query_listener)

So this is a little piece of logic that you need to provide to map your order to payment object. As you can see you can do all fancy stuff here to get order total value and currency code.

Note

If you don't know where to put your listeners code, we recommend to put it in listeners.py file and then add a line import listeners to the end of you models.py file. Both files (listeners.py and models.py) should be placed in on of your app (possibly an app related to order model).

Step 4. Handling changes of payment status

Required

Signals are also used to inform you that some particular payment just change status. In this case you will use getpaid.signals.payment_status_changed signal which is defined as:

payment_status_changed = Signal(providing_args=['old_status', 'new_status'])
payment_status_changed.__doc__ = """Sent when Payment status changes."""

example code that handles status change:

from getpaid import signals

def payment_status_changed_listener(sender, instance, old_status, new_status, **kwargs):
    """
    Here we will actually do something, when payment is accepted.
    E.g. lets change an order status.
    """
    if old_status != 'paid' and new_status == 'paid':
        # Ensures that we process order only one
        instance.order.status = 'P'
        instance.order.save()

signals.payment_status_changed.connect(payment_status_changed_listener)

For example: when payment changes status to 'paid', it means that the necessary amount was verified by your payment broker. You can now access payment.order object and do some stuff here.

Step 5. Handling new payment creation

Optional

For some reasons you may want to make some additiona checks before a new Payment is created or add some extra validation before the user is redirected to gateway url. You can handle this with getpaid.signals.order_additional_validation signal defined as:

order_additional_validation = Signal(providing_args=['request',
                                                 'order',
                                                 'backend'])
order_additional_validation.__doc__ = """
A hook for additional validation of an order.
Sent after PaymentMethodForm is submitted but before
Payment is created and before user is redirected to payment gateway.
"""

It may also (e.g. for KPI benchmarking) be important for you to how many and which payments were made. You can handle getpaid.signals.new_payment signal defined as:

new_payment = Signal(providing_args=['order', 'payment'])
new_payment.__doc__ = """Sent after creating new payment."""

Note

This method will enable you to make on-line KPI processing. For batch processing you can as well just query the database for Payment model.

Step 6. Setup your payment backends

Required

Please be sure to read carefully Backends section for information on how to configure particular backends. They will probably not work out of the box without providing some account keys or other credentials.

Running Tests

Does the code actually work?

source <YOURVIRTUALENV>/bin/activate
(myenv) $ pip install tox
(myenv) $ tox

Disclaimer

This project has nothing in common with getpaid plone project. It is mostly based on mamona project. This app was written because there was not a single reliable or simple to use payment processor dedicated to django. You can refer to other payment modules which does not meet our needs: Satchmo, python-payflowpro, django-authorizenet, mamona, django-paypal, django-payme.

Credits

Proudly sponsored by SUNSCRAPERS

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