From ea136ab6bcd2b1cf345d7a8ccaf2a4fa598a2364 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=AB=E9=9B=A8=E6=B0=B4=E8=BF=87=E6=BB=A4=E7=9A=84?=
 =?UTF-8?q?=E7=A9=BA=E6=B0=94-Rain?= <958414905@qq.com>
Date: Wed, 22 Nov 2023 17:22:09 +0800
Subject: [PATCH] fix: subform disappears (#3073)

---
 .../hooks/useLazyLoadDisplayAssociationFieldsOfForm.ts | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/packages/core/client/src/schema-component/antd/form-item/hooks/useLazyLoadDisplayAssociationFieldsOfForm.ts b/packages/core/client/src/schema-component/antd/form-item/hooks/useLazyLoadDisplayAssociationFieldsOfForm.ts
index 9a49b5e6f..7ac6a0d0f 100644
--- a/packages/core/client/src/schema-component/antd/form-item/hooks/useLazyLoadDisplayAssociationFieldsOfForm.ts
+++ b/packages/core/client/src/schema-component/antd/form-item/hooks/useLazyLoadDisplayAssociationFieldsOfForm.ts
@@ -27,7 +27,7 @@ const useLazyLoadDisplayAssociationFieldsOfForm = () => {
   const { isInSubForm, isInSubTable } = useFlag() || {};
 
   const schemaName = fieldSchema.name.toString();
-  const formValue = isInSubForm || isInSubTable ? subFormValue : form.values;
+  const formValue = _.cloneDeep(isInSubForm || isInSubTable ? subFormValue : form.values);
   const collectionFieldRef = useRef(null);
 
   if (collectionFieldRef.current == null) {
@@ -66,7 +66,13 @@ const useLazyLoadDisplayAssociationFieldsOfForm = () => {
       .parseVariable(variableString, formVariable)
       .then((value) => {
         nextTick(() => {
-          field.value = transformVariableValue(value, { targetCollectionField: collectionFieldRef.current });
+          const result = transformVariableValue(value, { targetCollectionField: collectionFieldRef.current });
+          // fix https://nocobase.height.app/T-2608
+          if (_.isEmpty(result)) {
+            field.value = null;
+          } else {
+            field.value = result;
+          }
         });
       })
       .catch((err) => {