Type-Safe Delegation for Dynamic Component Adaptation

One of the foremost aims of component technology is the replacement of large monolithic applications with sets of smaller components, whose particular functionality and interoperation can be adapted to users' needs. However, the adaptation mechanisms of component software are still limited. Most proposals concentrate on adaptations that can be achieved either at compile time or at link time. Current support for dynamic component adaptation, i.e. unanticipated, incremental modifications of a component system at run-time, is not sufficient. This position paper proposes object-based inheritance (also known as delegation) as a complement to purely forwarding-based object composition. It presents a type-safe integration of dynamic delegation into a class-based object model and shows how it overcomes the problems faced by forwarding-based component "wiring", how it supports independent extensibility of components and unanticipated, dynamic component adaptation. It also discusses the prerequisites that a component architecture must meet in order to support dynamic component adaptation.