Requirements and Use Case Model

The overall goal and vision for this application is to demonstrate, in the context of a simple and functional application, a technique for modeling Web applications with UML. Because the WAE is applicable for only client- and presentation-tier elements, most of the effort in this application can be found in these two tiers. The entity and data tiers, although functional, are not the focus of the development efforts and are not very interesting.

A new requirement for this second version of the Glossary application is to include an example of a «client script object». An excellent example of a well-engineered JavaScript object is the Menu object designed by Gary Smith of Netscape. This object was included in this application without modification and shows how you can build objects in JavaScript.

Another requirement is to allow HTML formatting in entry definitions. The application, however, must not require users to know or to understand HTML, so the use of HTML-encoded descriptions should be optional.

This application has only two simple use cases: Browse Entries and Edit Entry. The top-level model is shown in Figure E-1. The Edit Entry use case extends the normal browsing of the Glossary application by allowing an entry to be edited only in context, which, of course, means that it must be browsed to first.

Figure E-1. Glossary use cases

The basic flow scenarios for the two use cases are shown in Figures E-2 and E-3.

Figure E-2. Browse Entries basic flow

Figure E-3. Edit Entry basic flow