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XML
Standards News;
W3C Keeps Us On our Toes
During late December 1999 and early January 2000,
W3C has not let up on their relentless pace of
standards development. Here are some highlights
of their work.
HTML
4.01 Reaches Final Recommendation
Just
when we thought that HTML was old news, W3C comes up
with a new Recommendation on December 24th. This
new version of the HTML specification is 4.01.
This is the first update of HTML since April 24,
1998. Many changes in the document are quite
minor. Errors were corrected and clarifications
made. The style sheet was updated, a short table
of contents was added, and acknowledgements were
updated. ISO 14606 is now used to reference
character sets.
The
greatest changes were in the anchor, image, object,
and applet elements. In anchors it is now legal
for "name" and "id" to appear in
the same start tag when they are both defined for an
element. In the image element the
"name" attribute was added for backward
compatibility. Other minor changes were made to
these elements for the sake of compatibility.
A
change was also made to the SGML Declaration to
support hexadecimal numeric character
references. The lines :
DELIM
GENERAL SGMLREF
SHORTREF SGMLREF
Must
be changed to
DELIM
GENERAL SGMLREF
HCRO "&#x" -- 38 is the number for ampersand --
SHORTREF SGMLREF
and
<!SGML
"ISO 8879:1986"
must
be changed to
<!SGML "ISO 8879:1986 (WWW)"
XML
Schema Group Posts 2 Working Drafts on December 17
On December 17, a third working draft was posted
for XML Schema Part I: Structures and XML Schema Part
II: Datatypes, less than 3 months after the second
working drafts were posted on September
24th.
XML
Schema: Structures is part one of the draft specification
for the XML Schema definition language. This document
proposes facilities for describing the structure and
constraining the contents of XML 1.0 documents. The
schema language, which is itself represented in XML
1.0, provides a superset of the capabilities found
in XML 1.0 document type definitions (DTDs.)
Part
2 of XML Schema specifies a language for defining
datatypes to be used in XML Schemas and, possibly,
elsewhere.
To
find out the latest check the W3C site.
XSL
Posts a New Working Draft on January 12, 2000
On
January 12, a new Working Draft was posted for
Extensible Style Language (XSL). The previous
working draft was posted about 8 months earlier in
April of 1999. This version of the specification
has matured significantly. The document is much
more robust and contains many more graphics and
examples to help make its complex concepts
understandable by the Internet community.
This
version of the XSL specification has much more
detailed introductory material. XSL
transformation is introduced in this document and the
new XSLT specification is referenced An XSL
namespace is declared in the new working draft as
well. Section 4 is a new section that gives thorough
coverage to the Area Model that serves as the basis
for XSL. New diagrams are excellent!
Section 5 is also new. It provides a
comprehensive description of how properties are
specified, computed and inherited.
Also
impressive is the work that has been done with the
formatting objects and the formatting
properties. Each subject has been organized into
more discrete categories to help the reader understand
how the properties relate and should be used.
Objects and properties have been reworked and enhanced
as well.
See
XSL Transformations (XSLT) Specification
and Extensible Stylesheet Language (XSL) Specification
on the W3C site.
XLink
Posts a New Working Draft on January 19, 2000
The XML Linking Working
Group has been busy. They posted a working draft
on December 20, 1999 and another one on January 19,
2000. According to reports, the working group
believes that this draft is "near
completion," and invites public comment to www-xml-linking-comments@w3.org.
The specification "defines the XML Linking
Language (XLink), which allows elements to be inserted
into XML documents in order to create and describe
links between resources. It uses XML syntax to create
structures that can describe the simple unidirectional
hyperlinks of today's HTML as well as more
sophisticated links."
It
is important to note that there has been what some see
as a "radical" change in this newest working
draft. According to the note in this new WD:
"This
version of the specification has removed the element
method of link recognition (where there are elements
specified in the XLink namespace, not just attributes)
because it was deemed just a convenience feature that
lengthened the spec but offered no substantial
benefit." XLink's
namespace provides global attributes that can
be used on elements that are in any arbitrary
namespace. The global attributes are type,
href, role, title, show, actuate, from and to.
Document creators use global attributes to make the
elements in their own namespace, or even in a
namespace they don't control, recognizable as XLink
elements. The XLink attribute type
indicates the XLink element type (simple, extended,
locator, arc, resource, or title) that dictates the
constraints such an element must follow.
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