Mapping UML Web Navigation Stereotypes to XML Data Skeletons

Everyone who already experienced “getting lost” in a web site will agree that navigation support within such sites is a crucial topic in any but the most trivial web-based system. Modeling navigation links as special associations between classes in the UML let us arrive at the conclusion that class diagrams tend to become overloaded with links such that they are no longer understandable and their function as visual aids gets lost. Aiming for more transparent high level navigation modeling within the UML, this paper investigates, in a first step, well-known web design languages for their approaches to the modeling of navigation. By comparing Araneus, OOHDM, and RMM, in a subsequent step, we derive navigation primitives that we suggest to incorporate into the UML as navigational stereotypes. In a final step for two of these stereotypes we propose a concrete implementation in XML. These XML skeletons encode navigation information in a device-independent manner. Thus, UML static structure diagrams, extended by the navigation stereotypes introduced in this paper, have the potential to serve as a full-fledged notation supporting navigation design in web-based systems.