COMPOSITION OF ASPECTS BASED ON A RELATION MODEL: SYNERGY OF MULTIPLE PARADIGMS

Abstract

Software composition for timely and affordable software development and evolution is one of the oldest pursuits of software engineering. In current software composition techniques, Component-Based Software Development (CBSD) and Aspect-Oriented Software Development (AOSD) have attracted academic and industrial attention. Black box composition used in CBSD provides simple and safe modularization for its strong information hiding, which is, however, the main obstacle for a black box composite to evolve later. This implies that an application developed through black box composition cannot take advantage of Aspect-Oriented Programming (AOP) used in AOSD. On the contrary, AOP enhances maintainability and comprehensibility by modularizing concerns crosscutting multiple components but lacks the support for the hierarchical and external composition of aspects themselves and compromises the important software engineering principles such as encapsulation, which is almost perfectly supported in black box composition. The role and role model have been recognized to have many similarities with CBSD and AOP but have significant differences with those composition techniques as well. Although each composition paradigm has its own advantages and disadvantages, there is no substantial support to realize the synergy of these composition paradigms; the black box composition, AOP, and role model. In this paper, a new composition technique based on representational abstraction of the relationship between component instances is introduced. The model supports the simple, elegant, and dynamic composition of components with its declarative form and provides the hooks through which an aspect can evolve and a parallel developed aspect can be merged at the instance level.