[FR] Add delivery cost (excluding unit cost that already exists) in PO

Fixes #2694

InvenTree/order/api.py

@@ -743,6 +743,61 @@ class SOLineItemList(generics.ListCreateAPIView):
     ]
 
 
+class SOAdditionalLineItemList(generics.ListCreateAPIView):
+    """
+    API endpoint for accessing a list of SalesOrderAdditionalLineItem objects.
+    """
+
+    queryset = models.SalesOrderAdditionalLineItem.objects.all()
+    serializer_class = serializers.SOAdditionalLineItemSerializer
+
+    def get_serializer(self, *args, **kwargs):
+        try:
+            params = self.request.query_params
+
+            kwargs['order_detail'] = str2bool(params.get('order_detail', False))
+        except AttributeError:
+            pass
+
+        kwargs['context'] = self.get_serializer_context()
+
+        return self.serializer_class(*args, **kwargs)
+
+    def get_queryset(self, *args, **kwargs):
+
+        queryset = super().get_queryset(*args, **kwargs)
+
+        queryset = queryset.prefetch_related(
+            'order',
+        )
+
+        return queryset
+
+    filter_backends = [
+        rest_filters.DjangoFilterBackend,
+        filters.SearchFilter,
+        filters.OrderingFilter
+    ]
+
+    ordering_fields = [
+        'title',
+        'quantity',
+        'note',
+        'reference',
+    ]
+
+    search_fields = [
+        'title',
+        'quantity',
+        'note',
+        'reference'
+    ]
+
+    filter_fields = [
+        'order',
+    ]
+
+
 class SOLineItemDetail(generics.RetrieveUpdateDestroyAPIView):
     """ API endpoint for detail view of a SalesOrderLineItem object """