Occurrences

Paper

../papers/03-03-05/03-03-05.html

Date of Presentation

Wednesday, 22 May

Time of Presentation

14.00

Presentation Level

Technical

Abstract

XML well-formedness and validity are properties of documents at distribution time. But when a prose document is being created or edited, it will rarely be valid or even well-formed. This paper looks at three new or recent techniques. 1) Partial ordering is based on finding which tags (start- or end-) can feasibly appear before or after each other; unfeasible markup can be discovered before the document is even well-formed. 2) Weak validation is based on strength-reducing schema (or DTD) particles so that all elements are optional. Again, only infeasible documents will cause validation errors. 3) Schematron's phases provide a managed way to express many kinds of different constraints, allowing documents to be vaidated first against some criteria then others, suitable to the document's progress through a markup process. These can be contrasted to 'partial validity', where all the elements in every element must match unambiguously part of the way through the content model of the element. The first wave of XML editors required well-formedness and usually provided partial validity only, or even required strict validity. Examples of these new kinds of validation may be demonstrated using the Topologi Schematron Validator (a free tool) and the Topologi Markup Editor (a state-of-the-art commercial product for release in 1Q/2002)