Supporting Model-based Construction of Semantic Web Applications

Semantic annotation of Web content is in the core of the current Semantic Web Activity. The operationalization of the Semantic Web raises the challenge on how to systematically integrate semantic annotations into Web application pages that are dynamically created from database content and other underlying information resources. In this paper, we present VizCo a tool for systematically integrating RDF based application domain models, which describe domain concepts and their relationships, into the process of setting up dynamically generated Web application user interfaces and supporting their evolution. The form-based Web pages constituting the dynamically generated Web application user interface are annotated based on the underlying domain model. We follow a pragmatic approach that utilizes domain information extracted from application schemata and data as a starting point for domain modeling. The resulting domain model is flexibly coupled with the underlying data sources, where both the domain model and its coupling to the data source can be manually refined and extended. The presented VizCo tool enables the browsing of the domain model on different levels of abstraction and the visual definition of application specific views onto the domain model. Combined with further mapping tools, VizCo is used in our Web application development framework for coupling the domain model and, indirectly, the underlying application data with other Web application components, especially with elements of the user interface. In contrast to a direct coupling with the application data an additional semantic layer is introduced. The resulting domain model view descriptions are represented in an RDF-based format, which is dynamically translated into application data bindings at runtime. VizCo is part of a metadesign framework for the development, customization and evolution of semantic enabled Web applications supporting virtual information and knowledge environments.