add signin function

lib/model/do_model.dart

@@ -4,7 +4,7 @@ import 'dart:typed_data';
 
 import 'package:cloud_firestore/cloud_firestore.dart';
 import 'package:path/path.dart' as Path;
-import 'package:fcs/model/api_helper.dart';
+import 'package:fcs/fcs/common/api_helper.dart';
 import 'package:fcs/model/constants.dart';
 import 'package:fcs/pages/do/do_files.dart';
 import 'package:fcs/vo/do.dart';
@@ -27,7 +27,6 @@ class DOModel extends BaseModel {
     _loadDOs();
   }
 
-
   @override
   logout() async {
     if (listener != null) await listener.cancel();
@@ -247,7 +246,8 @@ class DOModel extends BaseModel {
         .where("status", isEqualTo: do_approved_status)
         .where("delivery_date", isGreaterThanOrEqualTo: date)
         .where("delivery_date", isLessThan: dateAddOne)
-        .orderBy("delivery_date").orderBy("user_name")
+        .orderBy("delivery_date")
+        .orderBy("user_name")
         .limit(100)
         .getDocuments();
     snapshots.documents.forEach((d) {