Reusing Application Frameworks Through Hooks

Object-oriented frameworks can be complex. Often, considerable time is needed to understand the framework, including not only what the framework does, but also how to use it. Techniques for documenting the design of a framework already exist, but less work has been done on documenting how to use the framework. We have developed the notion of hooks as a means of representing knowledge about the places in a framework that can be adapted by application developers to produce an application from the framework and have applied the concept to the SEAF (Size Engineering Application Framework) project. By describing the hooks, implicit knowledge about how to reuse the framework is made explicit and open to study, refinement or use. Having this knowledge available can make frameworks easier to reuse, since developers need not spend the time deriving the knowledge themselves. With hooks, a template is provided to describe the hooks and to capture all of the relevant knowledge in a form that provides guidance to application developers. This paper discusses the model of hooks as a means of capturing knowledge about how to reuse the framework, reports on our experience with hooks in the SEAF project and gives some initial assessment of the notion of hooks.