Modeling Data Entry and Operations in WebML

Web Modeling Language (WebML, http://webml.org) is a notation for visually specifying complex Web sites at the conceptual level. All the concepts of WebML are specified both graphically and in XML; in particular, navigation and composition abstractions are based on a restricted number of hypertext components (units) which are assembled into pages and interconnected by links. During implementation, pages and units are automatically translated into server-side scripting templates, which enable the display of data dynamically retrieved from heterogeneous data sources. This paper extends WebML with data entry and operation units, for gathering information from clients and invoking arbitrary operations. Predefined operations are also proposed as built-in primitives for supporting standard updates on the content of the underlying data sources (represented as entities and relationships). This natural extension of WebML permits the visual modeling of Web pages integrating read and write access, an essential aspect of many E-commerce applications (including user profiling and shopping cart management).