A Schema-Based Approach to HTML Authoring

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 are performed on a graphical user interface (GUI). Special attention has been given to the problem of schema evolution. In HSDL, the author can do nontrivial schema update operations even if classes have already been instantiated. The mapping from the schema to HTML, called compilation, is done by a series of programs in the programming language Scheme. These programs, called expanders, are integral parts of every schema. Although the default set of expanders will already provide fairly sophisticated HTML layout, users may easily adapt them to suit their special needs. A built-in, schema-aware HTML editor allows the integration of links defined in the schema into the HTML contents of a node.