Validating and Granting Access Rights

For new context and module added last week, I imitate some tests from example code provided and add few new tests. I also create some class to build dummy database to ease unit/integration testing. After going through some tests, I found out error when deleting data. Upon deletion, only data from 1 table is deleted, delete function suppose to remove few linked data across the database.

Before I look through into bugs of deletion, I make new implementation to validate user input in required textbox. If textbox is empty for non-nullable textbox, I create validation for system to prompt warning dialog to notify user. such as below :
if (string.IsNullOrEmpty(Wrapper.Variable))
{
_dialogService.ShowDialog( n, p, r );
return false;
}

Besides, Admin role is added to alter availability of buttons in system. I was been told to make initialization of adminUser as variable. Variable adminUser is set to bool = false initially, and will be implement in feature implementation. If bool adminUser = true, user is an admin user; bool adminUser = false, user is normal user. The reason of adding in admin role is to restrict some functionality of normal user. For normal user, the system will hinder user from edit or delete data in the system. In significant, admin user will be granted privilege to edit and delete.