Hypermedia presentation generation in Hera

Hera is a model-driven methodology for designing Semantic Web Information Systems (SWIS). Based on the principle of separation-of-concerns, Hera defines models to describe the different aspects of an SWIS. These models are represented using RDF, the foundation language of the Semantic Web. Hera is composed of two phases: the data collection phase, which integrates data from different sources, and the presentation generation phase, which builds a hypermedia presentation for the integrated data. The focus of this paper is on the hypermedia presentation generation phase and the associated model specifications. The Hera presentation generation phase has two variants: a static one that computes at once a full Web presentation, and a dynamic one that computes one-page-at-a-time by letting the user influence the next Web page to be presented. The dynamic variant proposes, in addition to the models from the static variant, new models to capture the data resulted from the user's interaction with the system. The implementation is based on a sequence of data transformations applied to the Hera models that eventually produces a hypermedia presentation.