NOTE: These slides have not been updated since 2003. They have been superseded by the book An Introduction to XML and Web Technologies Addison-Wesley, and the accompanying online material. Please see http://www.brics.dk/ixwt/ for more information. Anders Møller and Michael Schwartzbach, February 2006

THE XML REVOLUTION  -  TECHNOLOGIES FOR THE FUTURE WEB

Design requirements

The XML schema language shall be

1. more expressive than XML DTDs
2. expressed in XML
3. self-describing
4. usable by a wide variety of applications that employ XML
5. straightforwardly usable on the Internet
6. optimized for interoperability
7. simple enough to be implemented with modest design and runtime resources
8. coordinated with relevant W3C specs

1. be prepared quickly
2. be precise, concise, human-readable, and illustrated with examples

Structural requirements:

The XML schema language must define

1. mechanisms for constraining document structure (namespaces, elements, attributes) and content (datatypes, entities, notations)
2. mechanisms to enable inheritance for element, attribute, and datatype definitions
3. mechanism for URI reference to standard semantic understanding of a construct
4. mechanism for embedded documentation
5. mechanism for application-specific constraints and descriptions
6. mechanisms for addressing the evolution of schemata
7. mechanisms to enable integration of structural schemas with primitive data types

Unfortunately, their own XML Schema Recommendation does not fulfil all requirements (self-describing, simple, concise, human-readable, ...)

COPYRIGHT © 2000-2003 ANDERS MØLLER & MICHAEL I. SCHWARTZBACH