add validation for assistant employee start and end date

lib/views/pages/device_transfer/update_device_transfer.dart

@@ -385,20 +385,8 @@ class _UpdateDeviceTransferState extends State<UpdateDeviceTransfer> {
   List<File> _files = [];
 
   _update({required int status}) async {
-    if (_formModel.tbsTimer?.startAt == null) {
-      await Fluttertoast.showToast(msg: "Working Hours Required");
-      return false;
-    }
-    if (_formModel.tbsTimer?.endAt == null || isTimerRunning) {
-      await Fluttertoast.showToast(msg: "Please Stop The Timer");
-      return false;
-    }
-    if (!(_formKey.currentState!.validate())) {
-      setState(() {});
-      return false;
-    }
     _formKey.currentState!.save();
-
+    if (_validateForm()) {
       _formModel.statusValue = status;
       _formModel.isSender = widget.isSender;
       _formModel.assetTransferAttachments = [];
@@ -432,21 +420,37 @@ class _UpdateDeviceTransferState extends State<UpdateDeviceTransfer> {
             attachmentName = file.path.split("/").last;
             attachmentName = "$attachmentName|${base64Encode(file.readAsBytesSync())}";
           }
-        // if (widget.isSender) {
           _formModel.assetTransferAttachments!.add(AssetTransferAttachment(id: 0, attachmentName: attachmentName));
           _formModel.attachments = _formModel.assetTransferAttachments;
-        // }
-        // else {
-        //   _formModel.receiverAttachments!.add(AssetTransferAttachment(id: 0, attachmentName: attachmentName));
-        //   _formModel.attachments = _formModel.receiverAttachments;
-        // }
         }
       } catch (error) {
         print(error);
       }
-
       await _deviceTransferProvider.updateRequest(context, model: _formModel);
     }
+  }
+
+  bool _validateForm() {
+    if (_formModel.tbsTimer?.startAt == null) {
+      Fluttertoast.showToast(msg: "Working Hours Required");
+      return false;
+    }
+    if (_formModel.tbsTimer?.endAt == null || isTimerRunning) {
+      Fluttertoast.showToast(msg: "Please Stop The Timer");
+      return false;
+    }
+    if (_formModel.assistantEmployees != null) {
+      if (_formModel.modelAssistantEmployees?.startDate == null) {
+        Fluttertoast.showToast(msg: "Please Select Assistant Employee Start Time");
+        return false;
+      }
+      if (_formModel.modelAssistantEmployees?.endDate == null) {
+        Fluttertoast.showToast(msg: "Please Select Assistant Employee End Time");
+        return false;
+      }
+    }
+    return true;
+  }
 
   @override
   void initState() {
@@ -472,10 +476,12 @@ class _UpdateDeviceTransferState extends State<UpdateDeviceTransfer> {
         : (widget.model.receiverVisitTimers?.fold(0.0, (sum, item) => (sum ?? 0) + DateTime.parse(item.endDateTime!).difference(DateTime.parse(item.startDateTime!)).inSeconds) ?? 0);
     bool isTimerEnable = widget.isSender ? (!(_formModel.senderMachineStatusValue == 3)) : (!(_formModel.receiverMachineStatusValue == 3));
     return Scaffold(
-      appBar: DefaultAppBar(title: context.translation.transferAsset,
+      appBar: DefaultAppBar(
+        title: context.translation.transferAsset,
         onWillPopScope: () {
           _update(status: 0);
-        },),
+        },
+      ),
       key: _scaffoldKey,
       body: SafeArea(
         child: LoadingManager(