Make aggregated values computed when called instead of stored in DB

- GroupedOrder.total_price
- Order.articles_nb
- Order.price
- Item.ordered_nb

docs/development/architecture.md

@@ -22,22 +22,21 @@ classDiagram
       name
       deadline : DateTime
       delivery_date : Date
+      delivery_slot
       place
       description
       orga : CustomUser
-      total_price
     }
     class Item{
       name
       grouped_order : GroupedOrder
       ordered_nb
-      total_price
+      price
       max_limit
     }
     class Order{
         grouped_order : GroupedOrder
         author : OrderAuthor
-        price
         created_date
         note
     }

la_chariotte/order/migrations/0027_remove_groupedorder_total_price_and_more.py

@@ -0,0 +1,36 @@
+# Generated by Django 4.2.16 on 2024-10-31 21:27
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("order", "0026_groupedorder_delivery_slot"),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name="groupedorder",
+            name="total_price",
+        ),
+        migrations.RemoveField(
+            model_name="item",
+            name="ordered_nb",
+        ),
+        migrations.RemoveField(
+            model_name="order",
+            name="articles_nb",
+        ),
+        migrations.RemoveField(
+            model_name="order",
+            name="price",
+        ),
+        migrations.AlterField(
+            model_name="order",
+            name="created_date",
+            field=models.DateTimeField(
+                auto_now_add=True, verbose_name="Date et heure de commande"
+            ),
+        ),
+    ]

la_chariotte/order/models.py

@@ -25,7 +25,6 @@ class GroupedOrder(models.Model):
         max_length=100, null=True, blank=True, verbose_name="Lieu de livraison"
     )
     description = models.TextField("Description", null=True, blank=True)
-    total_price = models.DecimalField(max_digits=10, decimal_places=2, default=0)
     code = models.CharField(auto_created=True)
 
     def create_code_from_pk(self):
@@ -52,16 +51,12 @@ class GroupedOrder(models.Model):
         )
         self.code = f"{base_36_pk}{random_string}"[:code_length]
 
-    def compute_total_price(self):
+    @property
+    def total_price(self):
         price = 0
         for order in self.order_set.all():
             price += order.price
-        self.total_price = price
+        return 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
@@ -123,26 +118,24 @@ class Order(models.Model):
         GroupedOrder, on_delete=models.CASCADE, related_name="order_set"
     )
     author = models.ForeignKey(OrderAuthor, on_delete=models.CASCADE)
-    articles_nb = models.PositiveIntegerField(default=0)
-    price = models.DecimalField(max_digits=10, decimal_places=2, default=0)
     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):
+    @property
+    def 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
+        return articles_nb
-        self.save()
 
-    def compute_order_price(self):
+    @property
+    def 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
+        return price
-        self.save()
 
     def __str__(self):  # pragma: no cover
         return (
@@ -157,15 +150,13 @@ class Item(models.Model):
     price = models.DecimalField(max_digits=10, decimal_places=2)
     max_limit = models.PositiveSmallIntegerField(null=True, blank=True)
 
-    ordered_nb = models.IntegerField(default=0)
+    @property
-
+    def ordered_nb(self):
-    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
+        return ordered_nb
-        self.save()
 
     def get_total_price(self):
         """Returns the total price of all orders on this item"""

la_chariotte/order/views/grouped_order.py

@@ -150,12 +150,6 @@ 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
@@ -228,7 +222,6 @@ class GroupedOrderDuplicateView(UserIsOrgaMixin, generic.RedirectView):
         # duplicate each item and add it to new_grouped_order
         for item in initial_grouped_order.item_set.all():
             item.pk = None
-            item.ordered_nb = 0
             item.save()
             new_grouped_order.item_set.add(item)
 
@@ -300,7 +293,11 @@ class GroupedOrderExportView(UserIsOrgaMixin, generic.DetailView):
         context = super(GroupedOrderExportView, self).get_context_data(**kwargs)
         grouped_order = self.get_object()
 
-        items = grouped_order.item_set.filter(ordered_nb__gt=0).order_by("name")
+        items = [
+            item
+            for item in grouped_order.item_set.all().order_by("name")
+            if item.ordered_nb > 0
+        ]
         orders = grouped_order.order_set.all().order_by(
             "author__last_name", "author__first_name"
         )

la_chariotte/order/views/order.py

@@ -72,7 +72,6 @@ def place_order(request, code):
     if error_message:
         order.delete()
         author.delete()
-        grouped_order.compute_items_ordered_nb()
         return render(
             request,
             "order/grouped_order_detail.html",
@@ -103,8 +102,6 @@ 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 +120,6 @@ 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/test_order_views_grouped_order.py

@@ -1396,7 +1396,7 @@ class TestGroupedOrderSheetView:
         response = client_log.get(generate_sheet_url)
         assert response.status_code == 200
         assert response.context["grouped_order"] == grouped_order
-        assert response.context["items"].count() == 0
+        assert len(response.context["items"]) == 0
         assert len(response.context["orders_dict"]) == 0
 
         # we order some items in the grouped order
@@ -1404,7 +1404,7 @@ class TestGroupedOrderSheetView:
         response = client_log.get(generate_sheet_url)
         assert response.status_code == 200
         assert response.context["grouped_order"] == grouped_order
-        assert response.context["items"].count() == 2
+        assert len(response.context["items"]) == 2
         assert response.context["orders_dict"][order] == [3, 2]
         assert response.context["grouped_order"].total_price == 35
 

la_chariotte/tests/utils.py

@@ -44,11 +44,4 @@ def order_items_in_grouped_order(grouped_order):
     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()
     return order