INTEGRATING LEGACY SITES INTO WEB SERVICES WITH WEBXCRIPT

Abstract

Despite the recent uprising of the Web Services technology for programmatic interfaces of business-to-business (B2B) E-commerce services (e-services) over the Internet, most existing sites can only support human interactions with Hypertext Markup Language (HTML) through web browsers. Automating third-party client access into Web Services generally requires developing sophisticated programs to simulate human access by handling HTML pages. However, these HTML interfaces vary across web sites, and are often subject to changes. Client maintenance is therefore tedious and expensive. Even for the site owner, it may still require much effort in redeveloping the underlying presentation and application logics. This motivates our study for the requirement and the formulation of a conceptual model for such automation. Based on the requirement, we develop a novel approach to automating dialogs with web-based services (particularly for cross-organizational processes), using a high-level script language, called WebXcript language. The language provides features for HTML forms-based dialogues and eXtended Markup Language (XML) messaging. The XML syntax of WebXcript further enables convenient user authoring and easy engine development with extensively available XML tools. It supports expected responses and exception handling. We further propose a wrapper architecture based on WebXcript to integrate legacy sites into Web Services, where Web Service Definition Language (WSDL) interfaces are generated from high-level mappings from database or WebXcript parameter definitions. We demonstrate the applicability of our approach with examples in integrating distributed information, online ordering, and XML messaging, together with discussions on our experiences and the advantages of our approach.