The paper Overview of the OpenEdge Reference Architecture provides a substantial introduction to the layers of the Architecture and some thoughts on the ways in which you should think about how they can best be implemented in support of business applications. Other sets of papers on PSDN headed Implementing the OpenEdge Reference Architecture provide procedural examples of an implementation of the Architecture. The paper at hand is the first in a series describing an alternative implementation of the OpenEdge Reference Architecture (OERA). It assumes that you have read the Overview paper or are otherwise familiar with the layers of the Architecture and their role in application design.

The papers in this series show and describe key parts of an implementation that make use of the support for classes in ABL starting in OpenEdge 10.1. The code in the samples is based on the features available as of OpenEdge release 10.1B. This implementation also shows alternative ways of designing other aspects of the OERA, which are described when they arise in the discussion of the implementation.

This paper describes the elements of the hierarchy that make up Business Components such as Business Entities and their Data Access Objects. It walks through the structure of the hierarchy and how different elements contribute to it, focusing on the supporting classes that provide standard behavior. The paper finishes with a simple example that shows how the parts of the hierarchy work together.