def save_invoice(self, *args, **kwargs):
status_detail = kwargs.get('status_detail', 'tendered')
admin_notes = kwargs.get('admin_notes', None)
object_type = ContentType.objects.get(app_label=self._meta.app_label,
model=self._meta.module_name)
try: # get invoice
invoice = Invoice.objects.get(
object_type = object_type,
object_id = self.pk,
)
except ObjectDoesNotExist: # else; create invoice
# cannot use get_or_create method
# because too many fields are required
invoice = Invoice()
invoice.object_type = object_type
invoice.object_id = self.pk
# update invoice with details
invoice.title = "Registration %s for Event: %s" % (self.pk, self.event.title)
invoice.estimate = True
invoice.status_detail = status_detail
invoice.subtotal = self.amount_paid
invoice.total = self.amount_paid
invoice.balance = invoice.total
invoice.tender_date = datetime.now()
invoice.due_date = datetime.now()
invoice.ship_date = datetime.now()
invoice.admin_notes = admin_notes
invoice.save()
self.invoice = invoice
self.save()
return invoice
