Transformers-by-example: pushing reuse in conceptual web application modelling

S. Lechner, M. Schrefl
Lech04a (2004)
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.
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When defining a scheme 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 scheme is extended again and again in a similar manner. It would therefore be convenient for modelers to have transformers that, when applied to a scheme, perform such tasks.

In this paper, we present the language TBE (transformers-by-example) which allows defining transformers for WebML schemes by example, i.e. by giving an example of what is desired instead of specifying operations for achieving the result. The notation of transformers is thereby similar to one with which modelers are familiar. Further, each application of a transformer to a scheme can be parameterized such that the corresponding modelling task will be performed only within a specified part of the scheme. This makes it easy for modelers to define and apply transformers.

Keywords:web modelling, web schema transformers, query templates, generative templates, query by example