Adding subtotal, VAT and total to order. Also redirect to shop index if there are no products.

shop/models.py

@@ -70,6 +70,24 @@ class Order(CreatedUpdatedModel):
             sum=Sum('orderproductrelation__quantity')
         )['sum']
 
+    @property
+    def subtotal(self):
+        return self.products.aggregate(
+            sum=Sum(
+                models.F('orderproductrelation__product__price') *
+                models.F('orderproductrelation__quantity'),
+                output_field=models.IntegerField()
+            )
+        )['sum']
+
+    @property
+    def vat(self):
+        return (self.subtotal/100)*25
+
+    @property
+    def total(self):
+        return self.subtotal + self.vat
+
 
 class ProductCategory(CreatedUpdatedModel, UUIDModel):
     class Meta:

shop/templates/order_detail.html

@@ -48,7 +48,26 @@
 
 {% endfor %}
 
-{# TODO: Add total + VAT info #}
+  <tr>
+    <td colspan="2">
+    <td>
+      <strong>Subtotal</strong>
+    <td>
+      {{ order.subtotal }}
+
+  <tr>
+    <td colspan="2">
+    <td>
+      <strong>VAT (25%)</strong>
+    <td>
+      {{ order.vat }}
+
+  <tr>
+    <td colspan="2">
+    <td>
+      <strong>Total</strong>
+    <td>
+      {{ order.total }}
 
 </table>
 

shop/views.py

@@ -60,16 +60,13 @@ class OrderDetailView(LoginRequiredMixin, DetailView):
     context_object_name = 'order'
 
     def get(self, request, *args, **kwargs):
-        if self.get_object().user != request.user:
+        order = self.get_object()
+
+        if order.user != request.user:
             raise Http404("Order not found")
 
-        if self.get_object().paid:
+        if not order.products.count() > 0:
-            messages.error(request, 'This order is already paid for!')
+            return HttpResponseRedirect(reverse_lazy('shop:index'))
-            return HttpResponseRedirect('shop:order_detail')
-
-        if not self.get_object().products:
-            messages.error(request, 'This order contains no products!')
-            return HttpResponseRedirect('shop:order_detail')
 
         return super(OrderDetailView, self).get(request, *args, **kwargs)
 
@@ -111,6 +108,8 @@ class OrderDetailView(LoginRequiredMixin, DetailView):
         product_remove = request.POST.get('remove_product')
         if product_remove:
             order.orderproductrelation_set.filter(pk=product_remove).delete()
+            if not order.products.count() > 0:
+                return HttpResponseRedirect(reverse_lazy('shop:index'))
 
         return super(OrderDetailView, self).get(request, *args, **kwargs)