Extract middleware wishlist loading into WishlistManager and improve …

…notification sending

cartridge/shop/defaults.py

@@ -293,3 +293,15 @@
     editable=False,
     default=True,
 )
+
+register_setting(
+    name="SHOP_WISHLIST_NOTIFICATIONS",
+    label=_(
+        "Sends email notifications if an item in user's wishlist is in stock"
+    ),
+    description=_(
+        "Sends email notifications if an item in user's wishlist is in stock"
+    ),
+    editable=True,
+    default=True,
+)

cartridge/shop/managers.py

@@ -202,3 +202,24 @@ def get_valid(self, code, cart):
             if products.filter(variations__sku__in=cart.skus()).count() == 0:
                 raise self.model.DoesNotExist
         return discount
+
+
+class WishlistManager(Manager):
+
+    def from_request(self, request):
+        """
+        Gets current user's wishlist. Authenticated users' wishlists are stored
+        in the database, while unauthenticated users' are stored in a cookie.
+        Note that this method returns a `list` of SKUs in both cases, not a
+        `QuerySet` of `ProductVariation` objects.
+        """
+        if request.user.is_authenticated():
+            wishlist = []
+            skus = self.filter(user=request.user).values_list("sku", flat=True)
+            for sku in skus:
+                wishlist.append(sku)
+        else:
+            wishlist = request.COOKIES.get("wishlist", "").split(",")
+            if not wishlist[0]:
+                wishlist = []
+        return wishlist

cartridge/shop/middleware.py

@@ -29,13 +29,4 @@ class ShopMiddleware(SSLRedirect):
     """
     def process_request(self, request):
         request.cart = Cart.objects.from_request(request)
-        if not request.user.is_authenticated():
-            wishlist = request.COOKIES.get("wishlist", "").split(",")
-            if not wishlist[0]:
-                wishlist = []
-        else:
-            wishlist_items = Wishlist.objects.filter(user=request.user)
-            wishlist = []
-            for item in wishlist_items:
-                wishlist.append(item.sku)
-        request.wishlist = wishlist
+        request.wishlist = Wishlist.objects.from_request(request)

cartridge/shop/models.py

@@ -307,8 +307,11 @@ def update_stock(self, quantity):
                 self.product.save()
 
 
-@receiver(pre_save, sender=ProductVariation)
+@receiver(pre_save, sender=ProductVariation,
+          dispatch_uid="wishlist_notifications_on_save")
 def wishlist_notifications_on_save(sender, instance, **kwargs):
+    if settings.SHOP_WISHLIST_NOTIFICATIONS is not True:
+        return
     if instance.id:
         productvariation = ProductVariation.objects.get(pk=instance.id)
         old_stock = productvariation.num_in_stock
@@ -873,6 +876,8 @@ class Wishlist(models.Model):
     user = models.ForeignKey(User)
     sku = fields.SKUField()
 
+    objects = managers.WishlistManager()
+
     class Meta:
         unique_together = ('user', 'sku')
         verbose_name = _("Wishlist item")