Fix total_price annotation for ExtraLineItem

src/backend/InvenTree/order/api.py

@@ -80,6 +80,7 @@ class GeneralExtraLineList(SerializerContextMixin, DataExportViewMixin):
         queryset = super().get_queryset(*args, **kwargs)
 
         queryset = queryset.prefetch_related('order')
+        queryset = self.serializer_class.annotate_queryset(queryset)
 
         return queryset
 
@@ -96,6 +97,16 @@ class GeneralExtraLineList(SerializerContextMixin, DataExportViewMixin):
     filterset_fields = ['order']
 
 
+class GeneralExtraLineDetail:
+    """General template for ExtraLine detail API classes."""
+
+    def get_queryset(self, *args, **kwargs):
+        """Return the annotated queryset for this endpoint."""
+        queryset = super().get_queryset(*args, **kwargs)
+
+        return self.serializer_class.annotate_queryset(queryset)
+
+
 class OrderCreateMixin:
     """Mixin class which handles order creation via API."""
 
@@ -778,7 +789,7 @@ class PurchaseOrderExtraLineList(
     serializer_class = serializers.PurchaseOrderExtraLineSerializer
 
 
-class PurchaseOrderExtraLineDetail(RetrieveUpdateDestroyAPI):
+class PurchaseOrderExtraLineDetail(GeneralExtraLineDetail, RetrieveUpdateDestroyAPI):
     """API endpoint for detail view of a PurchaseOrderExtraLine object."""
 
     queryset = models.PurchaseOrderExtraLine.objects.all()
@@ -1113,7 +1124,7 @@ class SalesOrderExtraLineList(GeneralExtraLineList, OutputOptionsMixin, ListCrea
     serializer_class = serializers.SalesOrderExtraLineSerializer
 
 
-class SalesOrderExtraLineDetail(RetrieveUpdateDestroyAPI):
+class SalesOrderExtraLineDetail(GeneralExtraLineDetail, RetrieveUpdateDestroyAPI):
     """API endpoint for detail view of a SalesOrderExtraLine object."""
 
     queryset = models.SalesOrderExtraLine.objects.all()
@@ -1826,7 +1837,7 @@ class ReturnOrderExtraLineList(GeneralExtraLineList, OutputOptionsMixin, ListCre
     serializer_class = serializers.ReturnOrderExtraLineSerializer
 
 
-class ReturnOrderExtraLineDetail(RetrieveUpdateDestroyAPI):
+class ReturnOrderExtraLineDetail(GeneralExtraLineDetail, RetrieveUpdateDestroyAPI):
     """API endpoint for detail view of a ReturnOrderExtraLine object."""
 
     queryset = models.ReturnOrderExtraLine.objects.all()

src/backend/InvenTree/order/serializers.py

@@ -334,6 +334,7 @@ class AbstractExtraLineSerializer(
             'quantity',
             'reference',
             'target_date',
+            'total_price',
             # Filterable detail fields
             'order_detail',
             'project_code_label',
@@ -341,6 +342,19 @@ class AbstractExtraLineSerializer(
             *extra_fields,
         ]
 
+    @staticmethod
+    def annotate_queryset(queryset):
+        """Add annotations to the queryset.
+
+        - total_price: price * quantity, adjusted for the line discount
+        """
+        return queryset.annotate(
+            total_price=ExpressionWrapper(
+                F('price') * F('quantity') * (1 - F('discount') / Decimal(100)),
+                output_field=models.DecimalField(),
+            )
+        )
+
     quantity = serializers.FloatField()
 
     discount = InvenTreeDecimalField(required=False)
@@ -349,6 +363,8 @@ class AbstractExtraLineSerializer(
 
     price_currency = InvenTreeCurrencySerializer()
 
+    total_price = serializers.FloatField(read_only=True)
+
     project_code_label = common.filters.enable_project_label_filter()
 
     project_code_detail = common.filters.enable_project_code_filter()
@@ -369,6 +385,7 @@ class AbstractExtraLineMeta:
         'order_detail',
         'price',
         'price_currency',
+        'total_price',
         'link',
     ]