From 233672d822eb170a064dcddfd203a1fd4178f7e4 Mon Sep 17 00:00:00 2001
From: Oliver <oliver.henry.walters@gmail.com>
Date: Thu, 14 Oct 2021 14:25:39 +1100
Subject: [PATCH] Add new functionality to InvenTreeOrderingFilter

- Allow ordering by multiple field aliases
- Simply way to implement "integer ordering" functionality
---
 InvenTree/InvenTree/filters.py | 43 +++++++++++++++++++++++++++++-----
 InvenTree/build/api.py         |  7 +++++-
 2 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/InvenTree/InvenTree/filters.py b/InvenTree/InvenTree/filters.py
index cd1b769646..fbd1e53fe0 100644
--- a/InvenTree/InvenTree/filters.py
+++ b/InvenTree/InvenTree/filters.py
@@ -34,18 +34,49 @@ class InvenTreeOrderingFilter(OrderingFilter):
             Ordering fields should be mapped to separate fields
             """
 
-            for idx, field in enumerate(ordering):
+            idx = 0
 
-                reverse = False
+            ordering_initial = ordering
+            ordering = []
 
-                if field.startswith('-'):
+            for field in ordering_initial:
+                
+                reverse = field.startswith('-')
+
+                if reverse:
                     field = field[1:]
-                    reverse = True
 
+                # Are aliases defined for this field?
                 if field in aliases:
-                    ordering[idx] = aliases[field]
+                    alias = aliases[field]
+                else:
+                    alias = field
 
+                """
+                Potentially, a single field could be "aliased" to multiple field,
+                
+                (For example to enforce a particular ordering sequence)
+
+                e.g. to filter first by the integer value...
+
+                ordering_field_aliases = {
+                    "reference": ["integer_ref", "reference"]
+                }
+
+                """
+
+                if type(alias) is str:
+                    alias = [alias]
+                elif type(alias) in [list, tuple]:
+                    pass
+                else:
+                    # Unsupported alias type
+                    continue
+
+                for a in alias:
                     if reverse:
-                        ordering[idx] = '-' + ordering[idx]
+                        a = '-' + a
+
+                    ordering.append(a)
 
         return ordering
diff --git a/InvenTree/build/api.py b/InvenTree/build/api.py
index 7920003d8b..ea177c1570 100644
--- a/InvenTree/build/api.py
+++ b/InvenTree/build/api.py
@@ -17,6 +17,7 @@ from django_filters import rest_framework as rest_filters
 
 from InvenTree.api import AttachmentMixin
 from InvenTree.helpers import str2bool, isNull
+from InvenTree.filters import InvenTreeOrderingFilter
 from InvenTree.status_codes import BuildStatus
 
 from .models import Build, BuildItem, BuildOrderAttachment
@@ -68,7 +69,7 @@ class BuildList(generics.ListCreateAPIView):
     filter_backends = [
         DjangoFilterBackend,
         filters.SearchFilter,
-        filters.OrderingFilter,
+        InvenTreeOrderingFilter,
     ]
 
     ordering_fields = [
@@ -83,6 +84,10 @@ class BuildList(generics.ListCreateAPIView):
         'responsible',
     ]
 
+    ordering_field_aliases = {
+        'reference': ['integer_ref', 'reference'],
+    }
+
     search_fields = [
         'reference',
         'part__name',