The complete paypal workflow is now in place, including IPN.

paypal_registration/backend.py

@@ -31,6 +31,9 @@ class PaypalBackend(object):
          to *True* by default, which means you have to explicitly set it to
          False in production instances.
     * run syncdb to install the paypal_registration model
+    * ensure the sites model is correctly set up for your site in the django
+         admin. It is used to construct the paypal IPN url, so make sure it's
+         correct.
     * create the normal django-registration templates (for the default backend) as well as:
         * registration/pay_with_paypal.html which shows a 'pay now' button.
              There is an example template in the app templates directory for

paypal_registration/templates/registration/pay_with_paypal.html

@@ -16,9 +16,11 @@
 <form action="https://www.{% if use_sandbox %}sandbox.{% endif %}paypal.com/cgi-bin/webscr" method="post">
 <input type="hidden" name="cmd" value="_xclick">
 <input type="hidden" name="business" value="{{paypal_id}}" />
+<input type="hidden" name="notify_url" value="{{notify_url}}" />
+<input type="hidden" name="return" value="{{return_url}}" />
 <input type="hidden" name="no_shipping" value="1" />
-<input type="hidden" name="return" value="{% url confirm_payment_received %}" />
-<!-- widget specifying the amount. Feel free to use a hidden field -->
+<!-- widget specifying the amount. Feel free to use a hidden field, option,
+etc. Just name it 'amount' -->
 <select name="amount">
     <option value="300">1 yr</option>
     <option value="150">6 mos</option>

paypal_registration/urls.py

@@ -11,6 +11,7 @@
 
 from django.conf.urls.defaults import *
 from django.views.generic.simple import direct_to_template
+from django.views.decorators.csrf import csrf_exempt
 
 from registration.views import activate
 from registration.views import register
@@ -41,8 +42,11 @@
        'paypal_registration.views.pay_with_paypal',
        name='pay_with_paypal'),
    url(r'^payment_confirmation/$',
-       direct_to_template,
+       csrf_exempt(direct_to_template),
        {'template': 'registration/confirm_payment_received.html'},
        name="confirm_payment_received"),
+   url(r'^paypal_IPN_notify/$',
+       'paypal_registration.views.paypal_instant_notify',
+       name='paypal_notify'),
    (r'', include('registration.auth_urls')),
    )

paypal_registration/views.py

@@ -1,12 +1,31 @@
 from django.shortcuts import render_to_response
 from django.template import RequestContext
+from django.http import HttpResponse
 from django.conf import settings
+from django.core.urlresolvers import reverse
+from django.contrib.sites.models import RequestSite
+from django.contrib.sites.models import Site
+from django.views.decorators.csrf import csrf_exempt
 
 def pay_with_paypal(request, username):
     paypal_id = settings.PAYPAL_ID
     use_sandbox = getattr(settings, "USE_PAYPAL_SANDBOX", True)
+    if Site._meta.installed:
+        site = Site.objects.get_current()
+    else:
+        site = RequestSite(request)
+    paypal_ipn =  "http://%s%s" % (site.domain, reverse('paypal_notify'))
+    return_url = "http://%s%s" % (site.domain, reverse('confirm_payment_received'))
 
     return render_to_response("registration/pay_with_paypal.html",
             RequestContext(request,
                 {'paypal_id': paypal_id,
-                    'use_sandbox': use_sandbox}))
+                    'use_sandbox': use_sandbox,
+                    'notify_url': paypal_ipn,
+                    'return_url': return_url}))
+
+@csrf_exempt
+def paypal_instant_notify(request):
+    # FIXME: Some validation here is absolutely essential
+    print("\n\n\nPAYPAL SAID YES\n\n\n")
+    return HttpResponse("ACK")