XML-Based Automatic Web Presentation Generation Flavius Frasincar, Geert-Jan Houben Department of Computer Science Eindhoven University of Technology Eindhoven, the Netherlands flaviusf, houben @win.tue.nl Abstract: This paper presents a method that automates hypermedia presentation generation on the Web. The method is based on RMM (Relationship Management Methodology) for as- pects of hypermedia design. It distinguishes between the logical representation of the data and its actual presentation. Using new emerging Web technologies like XML (Extensible Markup Language) and XSLT (XML Stylesheet Language Transformation), we have implemented a prototype to experiment with the proposed method. Data filters written in XSLT prove to facil- itate the multi-phase hypermedia presentation generation method. Introduction World Wide Web (WWW) is the most important platform for information exchange between Internet users. As a result there is an increasing need for methodologies that support the design of Web-based Information Systems (WIS) (Isakowitz et al., 1998a). We consider WIS that integrate heterogeneous data sources, such as XML repositories, relational and object-oriented data bases etc. A user asks a query to such a system and as a result a presentation is generated (De Bra & Houben, 2000). The main focus of this paper is the question how to automate the process of generating such hypermedia presentations. Several hypermedia design methodologies are available, like RMM (Relationship Management Method- ology) (Isakowitz et al., 1995) and OOHDM (Object Oriented Hypermedia Design Methodology) (Schwabe et al., 1996). The design method that we use here applies the core of RMM for reasons of its simplicity and its E-R (Entity-Relationship) foundation. Extending the well-accepted E-R model to model information domains, and sub- sequently adding navigation structures to it, proves to be a solid ground on which to base the automatic generation of hypermedia presentations. Before we discuss the prototype implementation, we shortly mention the key concept (both in RMM and our specific design method) of ’slice’, which is used to denote meaningful presentation units. A slice groups together attributes and possibly other slices. In order to have a uniform approach to slice hierarchies (Isakowitz et al., 1998b) we consider primitive slices to be attributes. Each slice belongs to an entity but it can contain also slices belonging to different entities: in this case, the relationships between entities which make such an embedding possible are indicated. If the relationships are one-many an access structure (index, tour, and indexed guided tour) is associated to the slice nesting. Many-many relationships (from the E-R model) are decomposed in two one-many relationships. There are two types of slice relationships: aggregation (presented above) and reference (hyperlinks between slices). For a particular application, the application model describes all slices and their relationships (Isakowitz et al., 1998b), thus specifying the hypermedia aspects of the application. Due to the fact that each slice is owned by an entity and encapsulates some of the entity’s attributes we can view the application model as an extension of the E-R model, and thus as an important step in the design process of the hypermedia presentation.