Schema Driven User Interface Generation

Building Advanced Web-based Interfaces using presentation schema, XML, the DOM and background HTTP connections

Kent Fitch, AustLit Project AustLit Project, Academy Library, UNSW@ADFA, Australian Defence Force Academy, Canberra, ACT, 2600. Email: k.fitch@adfa.edu.au

Keywords

user interface generation, DHTML, schema, client-side javascript, usability

Abstract

As application user interfaces migrate to the web, developers need to provide the same functionality and response times in HTML based UIs as users have come to expect from desktop based standalone or client-server applications.

Simple "fill-in-the-form-and-press-SUBMIT" interfaces are not enough. However, the process of developing more sophisticated and interactive web based applications often degenerates into a tangle of client-side Javascript and chaotic form parameters.

This paper outlines some basic techniques which may be used to rapidly develop flexible web based user interfaces by:

• using XML to transmit data to and from the client
• dynamically building HTML forms in the client driven by the application data's "presentation schema"
• using synchronous background HTTP connections to populate selection lists and perform data validation

These techniques have been used successfully in two quite different distributed web applications - the document authoring system for the CSIRO web site and complex data maintenance functionality of Australian Literature Gateway (AustLit).