A Schema-Based Approach to HTML Authoring

Abstract

This paper presents a novel approach to high-productivity authoring of large, regularly structured hypertexts. By explicitly representing the objects in the hypertext and the relationships between them in a schema, it is possible to create, manipulate, and maintain large hyperdocuments with high efficiency. In the implementation, called the HSDL, all such schema operations areperformed on a graphical user interface (GUI). Special attention has been given to theproblem ofschema evolution. In HSDL, the author can do nontrivial schema update operations even ifclasses have already been instantiated. The mappingfrom the schema to HTML, called compilation, is done by a series ofprograms in theprogramming language Scheme. These programs, called expanders, are integral parts of every schema. Although the default set ofexpanders will already providefairly sophisticated HTML layout, users may easily adapt them to suit their special needs. A built-in, schema-aware HTML editor allows the integration oflinks defined in the schema into the HTML contents ofa node.