update invoice page

lib/pages/shipment/model/shipment_model.dart

@@ -148,6 +148,30 @@ class ShipmentModel extends BaseModel {
     return null;
   }
 
+  Future<List<Shipment>> getShipmentWithHandlingFee(
+      String fcsShipmentID, String userID) async {
+    String path = "/$shipments_collection";
+    try {
+      var q = Firestore.instance
+          .collection("$path")
+          .where("user_id", isEqualTo: userID)
+          .where("is_deleted", isEqualTo: false)
+          .where("handling_fee", isGreaterThan: 0)
+          .where("fcs_shipment_id", isEqualTo: fcsShipmentID);
+      var snaps = await q.getDocuments(source: Source.server);
+      List<Shipment> shipments = snaps.documents.map((snap) {
+        if (snap.exists) {
+          var s = Shipment.fromMap(snap.data, snap.documentID);
+          return s;
+        }
+      }).toList();
+      return shipments;
+    } catch (e) {
+      log.warning("Error!! $e");
+    }
+    return null;
+  }
+
   void initUser(user) {
     super.initUser(user);
   }