Thesis full text (PDF) - Politecnico di Milano

Figure 4.2: Example of WebML hypertext specification
4.2 Runtime Architecture of the Framework
We have implemented the execution of the existing framework in the context of the WebRatio
runtime architecture, extended to include interactions with the knowledge base. Figure 4.3
depicts the new architecture, where white boxes show the WebRatio existing components, blue
components are provided by the reasoner, and the yellow ones represent the runtime elements of
the framework.
The resulting architecture still follows the MVC2 architectural pattern, and comprises: (i) the
Web-based interfaces delivering the knowledge exploration and management functionalities, (ii)
the framework logic implementing these functionalities, (iii) the user interactions with the
framework, and (iv) the business logic providing access to the knowledge base and the XMI files
of UML models. This differentiates from the traditional MVC2 architecture because of (i) the
knowledge layer incorporating the knowledge base managed by the Pellet reasoning engine; and
(ii) the data layer containing only XMI files serializing the UML data models used by the
framework.
Notice that the framework logic is decoupled from the knowledge access and the data access by
introducing business logic services that are responsible to interact with Pellet and with the UML
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