Making DTD a Truly Powerful Schema Language

摘要

DTD is primarily used XML schema language to structure XML documents via a set of rules. But its too simple to represent XML document structures in a wide spectrum. Thus, many other XML schema languages such as XML Schema and SOX have been proposed to solve this problem. However these XML schema languages are too complicated for nonexperts to comprehend and use. In this paper, we extend DTD with object oriented mechanisms to solve this problem to meet the needs of complex applications and we call the new schema language Extended DTD. We describe Extended DTD components including their compositions, properties, constraints and validation rules. Then we come to conclusion.