add structure

lib/vo/notification.dart

@@ -0,0 +1,49 @@
+import 'package:cloud_firestore/cloud_firestore.dart';
+
+class Notification {
+  String id;
+  String itemID;
+  String itemNumber;
+  String itemType;
+  String desc;
+  DateTime time;
+  bool seen;
+
+  Notification(
+      {this.id,
+      this.itemID,
+      this.itemNumber,
+      this.itemType,
+      this.desc,
+      this.time,
+      this.seen});
+
+  String get getDesc =>
+      desc != null && desc.length > 30 ? desc.substring(0, 30) : desc;
+      
+  bool fromToday() {
+    var now = DateTime.now();
+    return time.day == now.day &&
+        time.month == now.month &&
+        time.year == now.year;
+  }
+
+  factory Notification.fromMap(Map<String, dynamic> map, String id) {
+    var _time = (map['time'] as Timestamp);
+
+    return Notification(
+      id: id,
+      time: _time?.toDate(),
+      itemID: map['item_id'],
+      itemNumber: map['item_number'],
+      itemType: map['item_type'],
+      desc: map['desc'],
+      seen: map['seen'],
+    );
+  }
+
+  @override
+  String toString() {
+    return 'Notification{id:$id,itemID:$itemID,itemNumber:$itemNumber,itemType:$itemType,desc:$desc,seen:$seen}';
+  }
+}