From 1dfcfaa6c3e6033e65786c52ede74db822d48dbb Mon Sep 17 00:00:00 2001
From: Oliver Walters <oliver.henry.walters@gmail.com>
Date: Sat, 27 Jun 2026 08:28:05 +0000
Subject: [PATCH] Prevent unnecessary re-rendering of table rows

---
 .../components/forms/fields/TableField.tsx    | 42 ++++++++++++++-----
 src/frontend/src/forms/StockForms.tsx         | 15 ++++++-
 2 files changed, 44 insertions(+), 13 deletions(-)

diff --git a/src/frontend/src/components/forms/fields/TableField.tsx b/src/frontend/src/components/forms/fields/TableField.tsx
index 08b520b95b..3e41a9f5c1 100644
--- a/src/frontend/src/components/forms/fields/TableField.tsx
+++ b/src/frontend/src/components/forms/fields/TableField.tsx
@@ -15,20 +15,12 @@ import { StandaloneField } from '../StandaloneField';
 export interface TableFieldRowProps {
   item: any;
   idx: number;
-  rowId?: string | number;
+  rowId: string | number;
   rowErrors: any;
   changeFn: (idx: number | string, key: string, value: any) => void;
   removeFn: (idx: number | string) => void;
 }
 
-function getRowIdentifier(item: any, idx: number): string | number {
-  if (item && typeof item === 'object') {
-    return item.pk ?? item.item ?? item.id ?? item.uuid ?? idx;
-  }
-
-  return item ?? idx;
-}
-
 function TableFieldRow({
   item,
   idx,
@@ -40,7 +32,7 @@ function TableFieldRow({
 }: Readonly<{
   item: any;
   idx: number;
-  rowId?: string | number;
+  rowId: string | number;
   errors: any;
   definition: ApiFormFieldType;
   changeFn: (idx: number, key: string, value: any) => void;
@@ -110,6 +102,34 @@ export function TableField({
   const valueRef = useRef(value);
   const onChangeRef = useRef(field.onChange);
   const rowIndexByIdRef = useRef(new Map<string | number, number>());
+  const generatedRowIdsRef = useRef(new WeakMap<object, string>());
+  const generatedRowIdCounterRef = useRef(0);
+
+  const getRowIdentifier = useCallback(
+    (item: any, idx: number): string | number => {
+      if (item && typeof item === 'object') {
+        const intrinsicId = item.pk ?? item.item ?? item.id ?? item.uuid;
+
+        if (intrinsicId !== undefined && intrinsicId !== null) {
+          return intrinsicId;
+        }
+
+        const existingGeneratedId = generatedRowIdsRef.current.get(item);
+
+        if (existingGeneratedId) {
+          return existingGeneratedId;
+        }
+
+        generatedRowIdCounterRef.current += 1;
+        const generatedId = `table-row-generated-${generatedRowIdCounterRef.current}`;
+        generatedRowIdsRef.current.set(item, generatedId);
+        return generatedId;
+      }
+
+      return item ?? idx;
+    },
+    []
+  );
 
   // Keep refs in sync with latest values without introducing them as deps
   valueRef.current = value;
@@ -123,7 +143,7 @@ export function TableField({
     });
 
     rowIndexByIdRef.current = nextRowIndexById;
-  }, [value]);
+  }, [value, getRowIdentifier]);
 
   const resolveRowIndex = useCallback((identifier: number | string) => {
     const mappedIndex = rowIndexByIdRef.current.get(identifier);
diff --git a/src/frontend/src/forms/StockForms.tsx b/src/frontend/src/forms/StockForms.tsx
index d293385238..08196f2737 100644
--- a/src/frontend/src/forms/StockForms.tsx
+++ b/src/frontend/src/forms/StockForms.tsx
@@ -634,7 +634,7 @@ function StockOperationsRow({
   returnStock?: boolean;
   record?: any;
 }) {
-  const rowId = props.rowId ?? props.idx;
+  const rowId = props.rowId;
 
   useWhyDidYouUpdate(`StockOperationsRow-${rowId}`, props);
 
@@ -847,9 +847,20 @@ function StockOperationsRow({
 const MemoizedStockOperationsRow = memo(
   StockOperationsRow,
   (previousProps, nextProps) => {
+    const prevItem = previousProps.props.item;
+    const nextItem = nextProps.props.item;
+
+    const itemUnchanged =
+      prevItem === nextItem ||
+      (prevItem?.pk === nextItem?.pk &&
+        prevItem?.quantity === nextItem?.quantity &&
+        prevItem?.status === nextItem?.status &&
+        prevItem?.packaging === nextItem?.packaging &&
+        prevItem?.merge === nextItem?.merge);
+
     return (
       previousProps.props.rowId === nextProps.props.rowId &&
-      previousProps.props.item === nextProps.props.item &&
+      itemUnchanged &&
       previousProps.props.rowErrors === nextProps.props.rowErrors &&
       previousProps.props.changeFn === nextProps.props.changeFn &&
       previousProps.props.removeFn === nextProps.props.removeFn &&