private void Save(object value) { if (this.person.Id > 0) { // update database .. tracker.AcceptChanges(); eventAggregator.GetEvent <PersonUpdatedSuccesfullyEvent>().Publish(new PersonEventArgs { Id = person.Id, DisplayName = person.FirstName }); } else { // validation ... save fakePeopleService.Add(person); tracker.AcceptChanges(); eventAggregator.GetEvent <PersonAddedEvent>().Publish(new PersonEventArgs { Id = person.Id, DisplayName = person.FirstName }); } SaveMessage = $"Save: {person.Id}, {person.FirstName} {person.LastName}, {person.EmailAddress} {value} {DateTime.Now.ToLongTimeString()}"; }