KB file added

Author: abineshsf3967

lib/helper/save_file_web.dart

@@ -0,0 +1,12 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:html';
+
+///To save the excel sheet in the web platform.
+Future<void> saveAndLaunchFile(List<int> bytes, String fileName) async {
+  AnchorElement(
+      href:
+          'data:application/octet-stream;charset=utf-16le;base64,${base64.encode(bytes)}')
+    ..setAttribute('download', fileName)
+    ..click();
+}