An aspect-oriented approach to the modularisation of context

Handling context is required for applications to dynamically and appropriately adapt to their changing environment. Incorporating context into applications involves the consideration of a set of concerns related to the handling of various context types and the adaptation of the application behaviour relative to the current context. These concerns are usually heavily tangled with the base code of the applications, resulting in code that is badly modularised and therefore is hard to understand, manage and modify. We propose a modularised design for the handling of different kinds of context using aspect-oriented programming techniques. We demonstrate that a context-aware application built in this manner exhibits improved modularity, with corresponding improvements in comprehensibility, manageability and maintainability. The proposed aspect-oriented modularisation is evaluated against traditional object-oriented techniques, and also against a popular context framework, using metrics indicating coupling, cohesion and complexity. The results show the positive effect of modular code on context-aware applications by quantitatively illustrating the improvements in modularisation quality factors.