add structure

lib/vo/inventory_taking.dart

@@ -0,0 +1,44 @@
+import 'package:cloud_firestore/cloud_firestore.dart';
+
+import 'inventory_line.dart';
+
+class InventoryTaking {
+  String accountID;
+  String id;
+  DateTime dateTime;
+  String userID;
+  String userName;
+  List<InventoryLine> inventoryLines = [];
+
+  bool linesLoaded = false;
+
+  InventoryTaking(
+      {this.accountID, this.id, this.userID, this.userName, this.dateTime});
+
+  factory InventoryTaking.fromMap(Map<String, dynamic> map, String id) {
+    var _dateTime = (map['date_time'] as Timestamp);
+
+    return InventoryTaking(
+      id: id,
+      accountID: map['account_id'],
+      userID: map['user_id'],
+      userName: map['user_name'],
+      dateTime: _dateTime?.toDate(),
+    );
+  }
+
+  Map<String, dynamic> toMap() {
+    List lines = inventoryLines.map((l) => l.toMap()).toList();
+    return {
+      'id': id,
+      'user_id': userID,
+      'user_name': userName,
+      'inventory_lines': lines,
+    };
+  }
+
+  @override
+  String toString() {
+    return 'InventoryTaking{id:$id,name:$userName}';
+  }
+}