Let’s Modularize the Data Model Specifications of the ObjectLens in VisualWorks/Smalltalk

Abstract

The ObjectLens framework of VisualWorks maps objects to ta bles. This mapping is described in a data mapping model, which itself is spe cified in one dataModelSpec method. This method is monolithic and defines the whole data model of an application. This is a suitable approach to start with. However, when the business area extends to a set of similar applications, like a software product family, each of these applications needs its own data mo del specification. All specifications of the product family would be quite si milar but there is no appropriate reuse-mechanism, which could be used. Consequently, the monolithic design specifications lead to a high degree of redundancy, which complicates software development and maintenance. Therefore, this paper describes an approach, which leads to a separation of the monolithic data model specifications. The main idea is to define the map pings of each class in the class itself using inheritance and generate the whole specification from a list of single class data models. In this way, declarative and generative programming techniques are combined.