Design of Extensible Component-Based Groupware

Abstract

Tailoring is identified as a key requirement for CSCW applications. One major tailoring mechanism is the extensionof an application at run-time to change its behavior. This article shows how synchronous CSCW component-based applicationscan be designed to be extensible at run-time. We propose to split the act of tailoring into two steps: thedesign-time customization of new components in visual builder tools and their insertion into the running application. Thus the customization tool is not required to be part of the application. This article presents a new design pattern for extensibility andgives several examples based on that pattern. With the help of the pattern extensible application frameworks can besystematically created from a non-extensible application design. The different possibilities to place insertionpoints into the application design are discussed with respect to flexibility and ease of deployment. Finally, wepresent the advantages and limitations of this approach.