Defining Web-schema transformers by-example

Project duration
July 2002 - September 2004
Project type
PhD Thesis Project  ( Stephan Lechner )

Short description
When defining a schema of a web application, modelers repeatedly perform modelling tasks like "after having defined an entity type, add a page class for displaying the entity type's content". Thereby, a schema is extended again and again in a similar manner. This suggests schema transformers that, when applied to a schema, perform such tasks. Such schema transformers shall be easy to use as well as easy to define for modelers. This pushes reuse in web application modelling and facilitates rapid prototyping and development of web applications.
To address the properties "ease-of-use" and "ease-of-definition", the project deals with defining Web-schema transformers by-example, i.e. by giving examples of Web-schemata which show what is desired instead of specifying operations which manipulate schemata in their internal representation. Transformers are thereby defined graphically and in a notation which is similar to one with which modelers are familiar. Further, each application of a transformer to a schema can be parameterized such that the corresponding modelling task will be performed only within a specified part of the schema.
The concept of defining transformers by-example can be introduced in various languages and tools for modelling web applications. This has yet been demonstrated on WebML, which is a popular web modelling language, and on WebRatio, which is a commercial tool for editing WebML schemata. However, besides the field of modelling web applications, the concept can be applied to other fields as well. For example, transformers defined by example could support the modelling of business processes, they could serve as language for precisely defining design patterns, or they could faciliate the definition of diagrams within the general-purpose diagram editor Microsoft Visio.

Project team
Stephan Lechner (DKE)

S. Lechner:
Web-scheme transformers by-example
(PhD Thesis, 2004)
S. Lechner, M. Schrefl:
Transformers-by-example: pushing reuse in conceptual web application modelling
In: H. M. Haddad et al. (eds.): Proceedings of the 19th ACM Symposium on Applied Computing (SAC 2004) - Volume 2 of 2, Special Track "Web Technologies and Applications (WTA)", Nicosia, Cyprus, March 14-17, 2004,ISBN 1-58113-812-1, ACM Press, pp. 1654-1661, 2004.
S. Lechner, M. Schrefl:
By-example schema transformers for supporting the process of conceptual web application modelling
Institute report 03.02, June 2003.
S. Lechner, M. Schrefl:
Defining Web Schema Transformers by Example
In: Valdimír Marík, Werner Retschitzegger, Olga Stepánková (eds.): Proceedings of the 14th International Conference on Database and Expert Systems Applications (DEXA 2003), Prague, Czech Republic, September 2003, Springer Verlag, pp. 46-56, 2003.
M. Karlinger:
A Framework for implementing Web Scheme Transformers By-Example
(Master Thesis, 2004)
Diplomarbeit, Betreuung: o. Univ.-Prof. Dr. Michael Schrefl, unter Anleitung von Dr. Stephan Lechner, ausgeführt an der Universität Linz, Institut für Wirtschaftsinformatik - Data & Knowledge Engineering, September 2004.