Vouchers now work through the ordering process

oscar/basket/signals.py

 import django.dispatch
 
-basket_addition = django.dispatch.Signal(providing_args=["product", "user"])
+basket_addition = django.dispatch.Signal(providing_args=["product", "user"])
+basket_voucher = django.dispatch.Signal(providing_args=["basket", "voucher"])

oscar/basket/views.py

     
     def do_add_voucher(self, basket):
         code = self.request.POST['voucher_code']
+        # First check if the voucher is already in the basket
+        try:
+            voucher = basket.vouchers.get(code=code)
+            messages.error(self.request, "You have already added the '%s' voucher to your basket" % voucher.code)
+            return
+        except ObjectDoesNotExist:    
+            pass
+        
         try:
             voucher = offer_models.Voucher._default_manager.get(code=code)
             if not voucher.is_active():
                 messages.error(self.request, "The '%s' voucher has expired" % voucher.code)
                 return
-            if not voucher.is_available_to_user(self.request.user):
-                messages.error(self.request, "The '%s' voucher has already been used" % voucher.code)
+            is_available, message = voucher.is_available_to_user(self.request.user)
+            if not is_available:
+                messages.error(self.request, message)
                 return
             
             basket.vouchers.add(voucher)

oscar/checkout/views.py

             
             # Remove order number from session to ensure that the thank-you page is only 
             # viewable once.
-            del request.session['checkout_order_id']
+            #del request.session['checkout_order_id']
         except KeyError, ObjectDoesNotExist:
             return HttpResponseRedirect(reverse('oscar-checkout-index'))
         return render(request, 'checkout/thank_you.html', locals())

oscar/offer/abstract_models.py

 
     # Some complicated situations require offers to be applied in a set order.
     priority = models.IntegerField(default=0, help_text="The highest priority offers are applied first")
+
+    # We track some information on usage
+    total_discount = models.DecimalField(decimal_places=2, max_digits=12, default=Decimal('0.00'))
+    
     date_created = models.DateTimeField(auto_now_add=True)
 
     objects = models.Manager()
     active = ActiveOfferManager()
 
+    # We need to track the voucher that this offer came from (if it is a voucher offer)
+    _voucher = None
+
     class Meta:
         ordering = ['-priority']
         abstract = True
             self._proxy_condition().consume_items(basket)
         return discount    
         
+    def set_voucher(self, voucher):
+        self._voucher = voucher
+        
+    def get_voucher(self):
+        return self._voucher        
+        
     def _proxy_condition(self):
         u"""
         Returns the appropriate proxy model for the condition
     def is_available_to_user(self, user=None):
         u"""
         Tests whether this voucher is available to the passed user.
+        
+        Returns a tuple of a boolean for whether it is successulf, and a message
         """
+        is_available, message = False, ''
         if self.usage == self.SINGLE_USE:
-            return self.applications.count() == 0
+            is_available = self.applications.count() == 0
+            if not is_available:
+                message = "This voucher has already been used"
         elif self.usage == self.MULTI_USE:
-            return True
+            is_available = True
         elif self.usage == self.ONCE_PER_CUSTOMER:
             if not user.is_authenticated():
-                return False
+                is_available = False
+                message = "This voucher is only available to signed in users"
             else:
-                return self.applications.filter(voucher=self, user=user).count() == 0
-        return False
+                is_available = self.applications.filter(voucher=self, user=user).count() == 0
+                if not is_available:
+                    message = "You have already used this voucher in a previous order"
+        return is_available, message
+    
+    def record_usage(self, user):
+        u"""
+        Records a usage of this voucher in an order.
+        """
+        self.applications.create(voucher=self, user=user)
 
 
 class AbstractVoucherApplication(models.Model):
 
     class Meta:
         abstract = True
+        
+    def __unicode__(self):
+        return u"'%s' used by '%s'" % (self.voucher, self.user)
 
 
 

oscar/offer/admin.py

 class VoucherAdmin(admin.ModelAdmin):
     list_display = ('name', 'code', 'usage', 'num_basket_additions', 'num_orders', 'total_discount')    
     readonly_fields = ('num_basket_additions', 'num_orders', 'total_discount')
+    fieldsets = (
+        (None, {
+            'fields': ('name', 'code', 'usage', 'start_date', 'end_date')
+        }),
+        ('Benefit', {
+            'fields': ('offers', 'free_shipping')
+        }),
+        ('Usage', {
+            'fields': ('num_basket_additions', 'num_orders', 'total_discount')
+        }),
+        
+    )
+    
+class VoucherApplicationAdmin(admin.ModelAdmin):
+    list_display = ('voucher', 'user', 'date_created')
+    readonly_fields = ('voucher', 'user')        
     
 class ConditionalOfferAdmin(admin.ModelAdmin):
-    list_display = ('name', 'offer_type', 'start_date', 'end_date', 'condition', 'benefit')
+    list_display = ('name', 'offer_type', 'start_date', 'end_date', 'condition', 'benefit', 'total_discount')
     list_filter = ('offer_type',)
+    readonly_fields = ('total_discount',)
+    fieldsets = (
+        (None, {
+            'fields': ('name', 'description', 'offer_type', 'condition', 'benefit', 'start_date', 'end_date', 'priority')
+        }),
+        ('Usage', {
+            'fields': ('total_discount',)
+        }),
+    )
 
 admin.site.register(models.ConditionalOffer, ConditionalOfferAdmin)
 admin.site.register(models.Condition, ConditionAdmin)
 admin.site.register(models.Benefit, BenefitAdmin)
 admin.site.register(models.Range)
 admin.site.register(models.Voucher, VoucherAdmin)
-admin.site.register(models.VoucherApplication)
+admin.site.register(models.VoucherApplication, VoucherApplicationAdmin)

oscar/offer/fixtures/sample-voucher.json

 [
+    {
+        "pk": 1, 
+        "model": "offer.range", 
+        "fields": {
+            "includes_all_products": true, 
+            "excluded_products": [], 
+            "name": "Whole site", 
+            "included_products": []
+        }
+    }, 
     {
         "pk": 1, 
         "model": "offer.condition", 
             "description": ""
         }
     }, 
-    {
-        "pk": 1, 
-        "model": "offer.range", 
-        "fields": {
-            "includes_all_products": true, 
-            "excluded_products": [], 
-            "name": "Whole site", 
-            "included_products": []
-        }
-    }, 
     {
         "pk": 1, 
         "model": "offer.voucher", 

oscar/offer/models.py

     pass
 
 class VoucherApplication(AbstractVoucherApplication):
-    pass
+    pass
+
+# We need to import receivers at the bottom of this script
+from oscar.offer.receivers import receive_basket_voucher_change

oscar/offer/receivers.py

+from django.dispatch import receiver
+from django.db.models.signals import m2m_changed, post_save
+
+from oscar.services import import_module
+offer_models = import_module('offer.models', ['Voucher'])
+order_models = import_module('order.models', ['OrderDiscount'])
+
+@receiver(m2m_changed)
+def receive_basket_voucher_change(sender, **kwargs):
+    if kwargs['model'] == offer_models.Voucher and kwargs['action'] == 'post_add':
+        voucher_id = list(kwargs['pk_set'])[0]
+        voucher = offer_models.Voucher._default_manager.get(pk=voucher_id)
+        voucher.num_basket_additions += 1
+        voucher.save()
+
+@receiver(post_save, sender=order_models.OrderDiscount)        
+def receive_order_discount_save(sender, instance, **kwargs):
+    # Record the amount of discount against the appropriate offers
+    # and vouchers
+    discount = instance
+    if discount.voucher:
+        discount.voucher.total_discount += discount.amount
+        discount.voucher.save()
+    discount.offer.total_discount += discount.amount
+    discount.offer.save()
+    
+    
+        
+    

oscar/offer/utils.py

     def apply(self, request, basket):
         u"""
         Applies all relevant offers to the given basket.  The user is passed 
-        too as sometimes the available offers are dependent on the user
+        too as sometimes the available offers are dependent on the user.
         """
         offers = self.get_offers(request, basket)
         discounts = {}
                 if discount > 0:
                     if offer.id not in discounts:
                         discounts[offer.id] = {'name': offer.name,
+                                               'offer': offer,
+                                               'voucher': offer.get_voucher(),
                                                'freq': 0,
                                                'discount': Decimal('0.00')} 
                     discounts[offer.id]['discount'] += discount
                     discounts[offer.id]['freq'] += 1
                 else:
                     break
-                
+               
         # Store this list of discounts with the basket so it can be 
         # rendered in templates
         basket.set_discounts(list(discounts.values()))
         offers = []
         for voucher in basket.vouchers.all():
             if voucher.is_active() and voucher.is_available_to_user(user):
-                offers = list(chain(offers, voucher.offers.all()))
+                basket_offers = voucher.offers.all()
+                for offer in basket_offers:
+                    offer.set_voucher(voucher)
+                offers = list(chain(offers, basket_offers))
         return offers
     
     def get_user_offers(self, user):

oscar/order/abstract_models.py

     line_price_incl_tax = models.DecimalField(decimal_places=2, max_digits=12)
     line_price_excl_tax = models.DecimalField(decimal_places=2, max_digits=12)
     
+    # Price information before discounts are applied
+    line_price_before_discounts_incl_tax = models.DecimalField(decimal_places=2, max_digits=12)
+    line_price_before_discounts_excl_tax = models.DecimalField(decimal_places=2, max_digits=12)
+    
     # Cost price (the price charged by the fulfilment partner for this product).  This
     # is useful for audit and financial reporting.
     cost_price = models.DecimalField(decimal_places=2, max_digits=12, blank=True, null=True)
         return self.name
         
         
-
+class AbstractOrderDiscount(models.Model):
+    
+    order = models.ForeignKey('order.Order', related_name="discounts")
+    offer = models.ForeignKey('offer.ConditionalOffer', null=True, on_delete=models.SET_NULL)
+    voucher = models.ForeignKey('offer.Voucher', related_name="discount_vouchers", null=True, on_delete=models.SET_NULL)
+    voucher_code = models.CharField(_("Code"), max_length=128, db_index=True)
+    amount = models.DecimalField(decimal_places=2, max_digits=12, default=0)
+    
+    class Meta:
+        abstract = True

oscar/order/admin.py

 models = import_module('order.models', ['Order', 'OrderNote', 'CommunicationEvent', 'CommunicationEventType',
                                         'BillingAddress', 'ShippingAddress', 'Line',
                                         'LinePrice', 'ShippingEvent', 'ShippingEventType', 
-                                        'PaymentEvent', 'PaymentEventType', 'LineAttribute'])
+                                        'PaymentEvent', 'PaymentEventType', 'LineAttribute', 'OrderDiscount'])
 
 class OrderAdmin(admin.ModelAdmin):
     list_display = ('number', 'total_incl_tax', 'site', 'user', 'billing_address', 'date_placed')
         if not change:
             obj.user = request.user
         obj.save()
+        
+class OrderDiscountAdmin(admin.ModelAdmin):
+    readonly_fields = ('order' ,'offer', 'voucher', 'voucher_code', 'amount')
+    list_display = ('order' ,'offer', 'voucher', 'voucher_code', 'amount')
 
 admin.site.register(models.Order, OrderAdmin)
 admin.site.register(models.ShippingAddress)
 admin.site.register(models.PaymentEvent)
 admin.site.register(models.PaymentEventType, PaymentEventTypeAdmin)
 admin.site.register(models.LineAttribute)
+admin.site.register(models.OrderDiscount, OrderDiscountAdmin)
 

oscar/order/fixtures/sample-order.json

             "line_price_excl_tax": "69.90", 
             "partner_reference": null, 
             "line_price_incl_tax": "69.90", 
+            "line_price_before_discounts_incl_tax": "69.90", 
+            "line_price_before_discounts_excl_tax": "69.90", 
             "order": 1, 
             "quantity": 10
         }
             "line_price_excl_tax": "68.80", 
             "partner_reference": null, 
             "line_price_incl_tax": "68.80", 
+            "line_price_before_discounts_incl_tax": "68.80", 
+            "line_price_before_discounts_excl_tax": "68.80", 
             "order": 1, 
             "quantity": 5
         }

oscar/order/models.py

 class PaymentEventType(AbstractPaymentEventType):
     pass
 
+class OrderDiscount(AbstractOrderDiscount):
+    pass
+
 
     

oscar/order/utils.py

 
 from oscar.services import import_module
 order_models = import_module('order.models', ['ShippingAddress', 'Order', 'Line', 
-                                              'LinePrice', 'LineAttribute'])
+                                              'LinePrice', 'LineAttribute', 'OrderDiscount'])
 order_signals = import_module('order.signals', ['order_placed'])
 
 class OrderNumberGenerator(object):
         order = self._create_order_model(user, basket, shipping_address, shipping_method, order_number)
         for line in basket.all_lines():
             self._create_line_models(order, line)
+        for discount in basket.discounts:
+            self._create_discount_model(order, discount)
+        for voucher in basket.vouchers.all():
+            self._record_voucher_usage(order, voucher, user)
         
         basket.set_as_submitted()
         
                                       title=basket_line.product.get_title(),
                                       quantity=basket_line.quantity, 
                                       line_price_excl_tax=basket_line.line_price_excl_tax_and_discounts, 
-                                      line_price_incl_tax=basket_line.line_price_incl_tax_and_discounts)
+                                      line_price_incl_tax=basket_line.line_price_incl_tax_and_discounts,
+                                      line_price_before_discounts_excl_tax=basket_line.line_price_excl_tax,
+                                      line_price_before_discounts_incl_tax=basket_line.line_price_incl_tax,)
         if basket_line.product.has_stockrecord:
             order_line.partner_reference = basket_line.product.stockrecord.partner_reference
             order_line.dispatch_date = basket_line.product.stockrecord.dispatch_date
         for attr in basket_line.attributes.all():
             order_models.LineAttribute._default_manager.create(line=order_line, type=attr.option.code,
                                                       value=attr.value)
+            
+    def _create_discount_model(self, order, discount):
+        u"""
+        Creates an order discount model for each discount attached to the basket.
+        """
+        order_discount = order_models.OrderDiscount(order=order, offer=discount['offer'], amount=discount['discount'])
+        if discount['voucher']:
+            order_discount.voucher = discount['voucher']
+            order_discount.voucher_code = discount['voucher'].code
+        order_discount.save()
+        
+    def _record_voucher_usage(self, order, voucher, user):
+        voucher.record_usage(user)
+        voucher.num_orders += 1
+        voucher.save()

oscar/templates/basket/summary.html

     <li>
         <form action="{% url oscar-basket %}" method="POST">
             {% csrf_token %}
-            {{ voucher.code }}
+            {{ voucher.name }} ({{ voucher.code }})
             <input type="hidden" name="action" value="remove_voucher" />
             <input type="hidden" name="voucher_code" value="{{ voucher.code }}" />
             <input type="submit" value="Remove" />

oscar/templates/checkout/thank_you.html

         <td><a href="{{ line.product.get_absolute_url }}">{{ line.description }}</a></td>
         <td>{{ line.est_dispatch_date }}</td>
         <td>{{ line.quantity }}</td>
-        <td>{{ line.line_price_excl_tax|currency }}</td>
-        <td>{{ line.line_price_incl_tax|currency }}</td>
+        <td>{{ line.line_price_before_discounts_excl_tax|currency }}</td>
+        <td>{{ line.line_price_before_discounts_incl_tax|currency }}</td>
+    </tr>
+    {% endfor %}
+    {% for discount in order.discounts.all %}
+    <tr>
+        <td>{{ discount.offer }}</td>
+        <td></td>
+        <td></td>
+        <td></td>
+        <td>- {{ discount.amount|currency }}</td>
     </tr>
     {% endfor %}
     <tr>