A Declarative Approach for Designing Web Portals

As many enterprise and industrial content management techniques are moving towards a distributed model, the need to exchange data between heterogeneous data sources in a seamless fashion is constantly increasing. These heterogeneous data sources could arise from server groups from different manufacturers or databases at different sites with their own schemas. Since its introduction in 1996, eXtensible Markup Language (XML) (W3C-XML, 2004) has established itself as the open, presentation independent data representation and exchange medium. XML provides a mechanism for seamless data exchange in many industrial informatics settings. In addition, XML is also emerging as the dominant standard for storing, describing, representing, and interchanging data among various enterprises systems and databases in the context of complex Web enterprises information systems (EIS). For such Web EIS (such as e-commerce and portals) to be successful, it is important to apply a high level, model-driven solution to design and implementation techniques that are capable of handling heterogonous schemas and documents. For this, we need a methodology that provides a higher level of abstraction of the domain in question, with rigorously defined standards that are to be more widely understood by all stakeholders of the system. With the introduction of XML Schema, which provides rich facilities for constraining, describing, and defining enterprise XML content, the XML technologies provide a good platform (and the flexibility) for modelling, designing and representing complex enterprise contents for building successful EIS. For example, a particular user may want to get an appropriate view of such XML data at a given location or level of the company. One way to handle such a complex task is to build semantic-aware enterprise Web sites and Web portals (Nakano, 2002; Tatnall, 2004). Furthermore, XML and user-aware dynamic user interface design technologies have gained a foothold in mainstream Web engineering research. With the introduction of XML schema (W3C-XSD, 2001) and related querying technologies, XML has established itself as the language for the Web. To enhance XML’s ability to include high level modelling capabilities and data abstraction, various supplementary techniques have been proposed by research communities including automated schemata transformation based design methodologies (Feng, Chang, & Dillon, 2003), view mechanisms and a high-level XML view design methodology (Rajugan, Chang, Dillon, & Feng, 2005, 2006). We argue that, unlike old Web portal designs, these new technologies and methodologies provide an added enhancement for developing meaningful Web portals. In addition, new security and access control mechanisms for XML and the Web have improved trustworthiness and collaboration among distributed Web communities and enterprises (Nakano, 2002; Steele, Gardner, Chandra, & Dillon, 2005). This results in design and development of distributed portals for information sharing and collaborative work such as 3rd party logistics (Chang et al., 2003; ITEC, 2002; Logistics, 2004).