Design and development of data-intensive web sites

Abstract

Data-intensive Web sites are large sites based on a back-end database, with a fairly complex hypertext structure. The paper develops two main contributions: (a) a specific design methodology for data-intensive Web sites, composed of a set of steps and design transformations that lead from a conceptual specification of the domain of interest to the actual implementation of the site; (b) a tool called HOMER, conceived to support the site design and implementation process, by allowing the designer to move through the various steps of the methodology, and to automate the generation of the code needed to implement the actual site.Our approach to site design is based on a clear separation between several design activities, namely database design, hypertext design, and presentation design. All these activities are carried on by using high-level models, all subsumed by an extension of the nested relational model; the mappings between the models can be nicely expressed using an extended relational algebra for nested structures. Based on the design artifacts produced during the design process, and on their representation in the algebraic framework, HOMER is able to generate all the code needed for the actual generation of the site, in a completely automatic way.

WebRatio BPM: A Tool for Designing and Deploying Business Processes on the Web

“…In our work, both aspects are considered: like in UWE, we preserve the process model as an additional domain model in the application data; as in OO-H, we provide semi-automatic generation of WebML navigational model skeletons directly from the process model. Among the other existing models, we can mention Araneus [10], that has been extended with a workflow conceptual model, allowing the interaction between the hypertext and an underlying workflow management system. In OOHDM [14], the content and navigation models are extended with activity entities and activity nodes respectively, represented by UML primitives.…”

Time: A Coordinate for Web Site Modelling

“…This has little to do with transaction time. In some sense (we will come back to this point later), versioning can give rise to different coordinates (at least partially independent), which correspond to the oft cited components of a Web site, data, hypertext, presentation [11,4,5]:…”

“…It should be noted that, if the design process is supported by a tool that allows the specification of transformation primitives [5], then the possible transformations can be known a priori, in the same way as suggested by Kim and Chou [12] for version management of objectoriented databases.…”

“…Specifically, we focus our attention on data-intensive Web sites, where more structured models can definitely be useful: they can be described by means of schemes (logical hypertext scheme and associated presentation) and can be obtained by applying suitable algebraic transformations to the data stored in an underlying database (see Atzeni et al [5]). …”

“…We will not consider query languages, which indeed constitute a major issue in temporal database management, since in our approach they can be seen as an "implementation" issue: our major goal is to understand which could be the right way to organize information to be offered to Web users; in turn, in a data-intensive site, this information should be extracted from a database, probably by means of time-aware expressions, which could be written in a temporal query language or in a standard query language, but automatically generated by means of a CASE tool [5].…”