Extending the MDO Model

Suppose that you are tracking bugs reported on your Visual Basic projects. The MDO Model already accommodates information about your projects. You want to supplement that information with a description of each bug, the project against which the bug is reported, and the person who discovers each bug. You also want a new Visual Basic application with which you can enter and later examine reported bugs.

Before you create the Visual Basic project for this new application, you must extend the MDO Model to include a bug class, a person class, a person-reports-bug relationship type, and a project-has-bug relationship type. (To learn how to extend an information model, see Information Model Creation.)

When you create the project, add the following references:

1. To the Microsoft Development Objects type library. You must add this reference because your project will manipulate the contents of the MDO Model directly.
   
   
2. To the Microsoft Repository type library. You must add this reference because your project will manipulate the contents of the repository directly.

Before you run your new application, you must ensure that each of your Visual Basic projects is represented in the repository. Thus, you must register the Repository Add-in for Visual Basic as an add-in and open and close each project on which you want to track bugs.

Your new application can be run independent of the Visual Basic interactive development environment. Thus, do not implement it as a Visual Basic add-in. You need not register for any events triggered by the Repository Add-in for Visual Basic. Therefore, you do not need to add a reference to the Microsoft Repository Add-In type library.

After it has run, your new application will accept input from users, validate the input against project-related data from the MDO Model, and add bug-related information to your MDO Model extensions.