Refactor compuation of counters and prices in order objects

la_chariotte/order/models.py

@@ -52,17 +52,6 @@ class GroupedOrder(models.Model):
         )
         self.code = f"{base_36_pk}{random_string}"[:code_length]
 
-    def compute_total_price(self):
-        price = 0
-        for order in self.order_set.all():
-            price += order.price
-        self.total_price = price
-        self.save()
-
-    def compute_items_ordered_nb(self):
-        for item in self.item_set.all():
-            item.compute_ordered_nb()
-
     def get_total_ordered_items(self):
         total_nb = 0
         for item in self.item_set.all():
@@ -128,28 +117,33 @@ class Order(models.Model):
     created_date = models.DateTimeField("Date et heure de commande", auto_now_add=True)
     note = models.TextField(max_length=200, null=True, blank=True)
 
-    def compute_order_articles_nb(self):
-        """Computes the number of articles in this order"""
-        articles_nb = 0
-        for ord_item in self.ordered_items.all():
-            articles_nb += ord_item.nb
-        self.articles_nb = articles_nb
-        self.save()
-
-    def compute_order_price(self):
-        """Computes the total price of the order"""
-        price = 0
-        for ord_item in self.ordered_items.all():
-            price += ord_item.get_price()
-        self.price = price
-        self.save()
-
     def __str__(self):  # pragma: no cover
         return (
             f"Commande de {self.author} pour la commande groupée"
             f" {self.grouped_order.code}"
         )
 
+    def create_ordered_item(self, nb, item):
+        """Create an OrderItem instance and update counters/price accordingly"""
+        self.ordered_items.add(OrderedItem.objects.create(nb=nb, order=self, item=item))
+        item.ordered_nb += nb
+        item.save()
+        self.articles_nb += nb
+        self.price += nb * item.price
+        self.grouped_order.total_price += nb * item.price
+        self.grouped_order.save()
+        self.save()
+
+    # overwrite delete() to update counters/prices
+    def delete(self, *args, **kwargs):
+        for ord_item in self.ordered_items.all():
+            ord_item.item.ordered_nb -= ord_item.nb
+            ord_item.item.save()
+        self.grouped_order.total_price -= self.price
+        self.grouped_order.save()
+        self.author.delete()
+        super().delete(*args, **kwargs)
+
 
 class Item(models.Model):
     name = models.CharField(max_length=100)
@@ -159,14 +153,6 @@ class Item(models.Model):
 
     ordered_nb = models.IntegerField(default=0)
 
-    def compute_ordered_nb(self):
-        """Computes the number of times this item has been ordered"""
-        ordered_nb = 0
-        for order in self.orders.all():
-            ordered_nb += order.nb
-        self.ordered_nb = ordered_nb
-        self.save()
-
     def get_total_price(self):
         """Returns the total price of all orders on this item"""
         return self.price * self.ordered_nb

la_chariotte/order/views/grouped_order.py

@@ -151,12 +151,6 @@ class GroupedOrderOverview(UserIsOrgaMixin, generic.DetailView):
         # Staff can see but not edit grouped orders
         return super().test_func() or self.request.user.is_staff
 
-    def get(self, request, *args, **kwargs):
-        # Compute grouped order total price before display
-        self.get_object().compute_total_price()
-        self.get_object().compute_items_ordered_nb()
-        return super().get(self, request, *args, **kwargs)
-
     def get_context_data(self, **kwargs):
         context = super(GroupedOrderOverview, self).get_context_data(**kwargs)
         # Add share link to context
@@ -255,10 +249,10 @@ class GroupedOrderDeleteView(UserIsOrgaMixin, generic.DeleteView):
         return reverse_lazy("order:index")
 
     def form_valid(self, form):
-        # Delete related OrderAuthors
+        # Delete related Orders
         grouped_order = self.get_object()
         for order in grouped_order.order_set.all():
-            order.author.delete()
+            order.delete()
         return super().form_valid(form)
 
 

la_chariotte/order/views/order.py

@@ -66,13 +66,11 @@ def place_order(request, code):
         if error_message:
             break  # stop creating items if there is an error
         if quantity > 0:
-            OrderedItem.objects.create(nb=quantity, order=order, item=item)
+            order.create_ordered_item(nb=quantity, item=item)
 
     # Redisplay the form with error messages if there is an error
     if error_message:
         order.delete()
-        author.delete()
-        grouped_order.compute_items_ordered_nb()
         return render(
             request,
             "order/grouped_order_detail.html",
@@ -90,7 +88,6 @@ def place_order(request, code):
     # Redisplay the form with error messages if there is an error
     if error_message:
         order.delete()
-        author.delete()
         return render(
             request,
             "order/grouped_order_detail.html",
@@ -103,8 +100,6 @@ def place_order(request, code):
         )
 
     # Send confirmation mail and redirect to confirmation page
-    order.compute_order_price()
-    grouped_order.compute_items_ordered_nb()
     send_order_confirmation_mail(order)
 
     # Redirect to prevent data from being posted twice when the user hits the Back
@@ -123,7 +118,6 @@ def validate_item_ordered_nb(item, ordered_nb):
 
 def validate_articles_ordered_nb(order):
     """Return an error if no items are ordered"""
-    order.compute_order_articles_nb()
     if order.articles_nb == 0:
         return "Veuillez commander au moins un produit"
     return None

la_chariotte/tests/utils.py

@@ -23,8 +23,8 @@ def create_grouped_order(
 
 def order_items_in_grouped_order(grouped_order):
     """Creates 2 OrderedItems and orders in the given grouped order. Returns the order"""
-    item_1 = grouped_order.item_set.create(name="test item", price="2")
-    item_2 = grouped_order.item_set.create(name="test item 2", price="9")
+    item_1 = grouped_order.item_set.create(name="test item", price=2)
+    item_2 = grouped_order.item_set.create(name="test item 2", price=9)
     author_1 = models.OrderAuthor.objects.create(
         first_name="bob", last_name="lescargot", phone="000", email="bob@escargot.fr"
     )
@@ -40,15 +40,8 @@ def order_items_in_grouped_order(grouped_order):
     order = grouped_order.order_set.create(author=author_1)
     order_2 = grouped_order.order_set.create(author=author_2)
     order_3 = grouped_order.order_set.create(author=author_3)
-    models.OrderedItem.objects.create(order=order, item=item_1, nb=3)
-    models.OrderedItem.objects.create(order=order, item=item_2, nb=2)
-    models.OrderedItem.objects.create(order=order_2, item=item_1, nb=1)
-    models.OrderedItem.objects.create(order=order_3, item=item_2, nb=1)
-    item_1.compute_ordered_nb()
-    item_2.compute_ordered_nb()
-    order.compute_order_price()
-    order_2.compute_order_price()
-    order_3.compute_order_price()
-    grouped_order.compute_total_price()
-    grouped_order.save()
+    order.create_ordered_item(item=item_1, nb=3)
+    order.create_ordered_item(item=item_2, nb=2)
+    order_2.create_ordered_item(item=item_1, nb=1)
+    order_3.create_ordered_item(item=item_2, nb=1)
     return order