iEditors: Extending iTask with interactive plug-ins

Abstract

The iTask library of Clean enables the user to specify web-enabled workflow systems on a high level of abstraction. Details like client-server communication, storage and retrieval of state information, HTML generation, and web form handling are all handled automatically. Using only standard HTML web browser elements also has a disadvantage: it does not offer the same level of interaction as we are used to from desktop applications. Browser plug-ins can fill this gap. They make it possible to extend web-applications with interactive functionality like the making of drawings. In this paper we explain how plug-ins can be nicely integrated in the iTask system. A special feature of the integration is the possibility for a plug-in to use Clean functions as call-back mechanism for the handling of events. These call-backs can be handled on the server as well as on the client. As a result we are now able to create interactive iTask applications (iEditors) using plug-ins like graphical editors. Although complicated, distributed multi-user applications can be created in this way, reasoning about the program remains easy since all code is generated from one and the same source: the high-level iTask specification in Clean. © 2011 Springer-Verlag.