Add myBook Reference [1]

Exclusive Collection

By making the books collection exclusive it becomes very closely associated with its Borrower object. In fact, it is a sub-object, which has the following consequences

• You do not need to create the books collection object. It is automatically created when the Borrower object is created.
• You do not need to delete the books collection object. It is automatically deleted when the Borrower object is deleted.
• You cannot reassign the books reference to another BookDictionary object.

Inverse Reference

The books reference enables the Borrower to know (and navigate to) the checked out Books. Because a Book needs to know if it is checked out and to whom, you will define the inverse reference next.

Instructions

1. In the Class Browser, select the Borrower class.
2. Select the Properties | Add Reference... menu command.
3. Enter books as the name.
4. Select BookDictionary as the type.
5. Change the access to public.
6. Click the Define Inverse... button. The dialog expands.
   Further instructions are given on the next page.