XML Update

http://www.w3.org/2000/Talks/www9-xml/

Background: XML in Web Architecture

• Web Architecture = Data Formats, Protocols, and Naming/Addressing Syntax;
  originally: HTML, HTTP, URIs
• Data formats and protocols evolve; URI syntax does not
• HTML was layered on SGML syntax
• XML constrains SGML so that parsing does not rely on a DTD
• XML vocabularies (HTML, SVG, RDF, MathML, SMIL, ...) are grounded in URI space

Background: Recommendations

• XML 1.0, Feb '98
  universal format for structured documents and data
  includes legacy vocabulary description mechanism: DTDs
• Namespaces in XML, Jan '99
  connects XML vocabularies to URI space
• XPath, XSLT, Nov '99
  document transformation, including path expressions

Work in Progress: Working Groups

• Core
  • co-chairs: Paul Grosso of Arbortext and Arnaud Le Hors of IBM
  • 23 persons representing 14 member orgs
• Linking
  • co-chairs: Eve Maler of Sun Microsystems and Daniel Veillard of the W3C;
    Ron Daniel of Datafusion serves as the XML Linking Interest Group chair.
  • membership: 17 persons from 12 W3C Member Organizations
• Query
  • chair: Paul Cotton of IBM
  • membership: 60 persons representing 38 member orgs
• Schema
  • co-chairs: Dave Hollander of CommerceNet and C. M. Sperberg-McQueen, of W3C
  • membership: 49 persons representing 32 W3C member orgs
• ... nearby: XML Signature, DOM, XSL, HTML, SVG, SMIL, ...

XML Linking in Brief

generalize HTML A, IMG, LINK

<my:crossReference
  xmlns:xlink="http://www.w3.org/1999/xlink"
  xmlns:my="http://me.com/"
  xlink:type="simple"
  xlink:href="students.xml"
  xlink:role="studentlist" xlink:title="Student List"
  xlink:show="new" xlink:actuate="onRequest">
    Current List of Students
</my:crossReference>

XPointer in Brief

• fragment identifier syntax for text/xml
• point to named or unnamed structures
• examples:
  • #intro
  • #xpointer(id("intro"))
  • #xpointer(book/chapter[position() <= 5])

XML Base in Brief

generalized form of HTML <base>

<ol xml:base="/hotpicks">
  <li><a href="pick1.xml">Hot Pick #1</a></li>
  <li><a href="pick2.xml">Hot Pick #2</a></li>
  <li><a href="pick3.xml">Hot Pick #3</a></li>
</ol>

XML Information Set in Brief

• data model for tree of elements with attributes
  • largely implicit in the XML 1.0 spec
  • motivated by questions from DOM development
• named properties: children, base URI, etc.
  • provides shared terminology for future specs
• other specs (e.g. XML Schema) may refine this model with other properties

XInclude in Brief

General purpose inclusion of (part of) one document in another:

<x xmlns:xinclude="...">
  <xinclude:include href="something.xml"/>
</x>

Work in Progress: Status

• XML Inclusions (XInclude) released 22 March 2000
• XML Base last call ended March 2000
• XML Linking Language (XLink) last call ended March 2000
• XML Information Set last call ended Jan 2000
• XML Pointer Language (XPointer) last call ended 27 Dec 1999
• XML Fragment Interchange revised Jun 1999 after Last Call
• ... Canonical XML moved to XML Signature working group
• ... more on XML Schema, XML Query in other presentations

Plans: XML and Protocols

• submissions: WBXML, ICE, SOAP
• phased workshop:
  • XTech Mar 2000
  • IETF 47
  • WWWW9