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XML Standards Update; XSL 1.0 and XML Infoset are RecommendationsXSL 1.0 Becomes a W3C RecommendationOn October 16, 2001 the W3C released the Extensible Stylesheet Language (XSL) 1.0 as a Recommendation. XSL stylesheets are used to express how source content should be styled, laid out, and paginated onto a presentation medium such as a browser window, a pamphlet or a book. To date, XML has been most used as a format for structured data. Ironically, even though the roots of XML came from the publishing world, XML cannot effectively be used for sophisticated document-driven purposes because advanced levels of formatting and structural transformation common to proprietary publishing tools simply were not available. One reason for this has been the lack, until now, of a sophisticated style sheet specification designed for XML-based document publishing. XSLT 1.0, the XML language which performs transformations on XML data and documents, became a W3C Recommendation back in November 1999. Significant usage of XSLT has been seen for both data-centric and document centric uses. The new Recommendation, XSL 1.0, builds on XSLT 1.0, and provides users with the ability not only to transform XML data into HTML, but to describe how XML data and documents are to be formatted for direct browser display. XSL 1.0 does this by defining "formatting objects," such as footnotes, headers, columns, and other features common to paged media. An XSL engine would take the XML document and the XSL stylesheet, and would produce a rendering of the document. XSLT 1.0 makes it possible to significantly change the original structure of an XML document (automatic generation of tables of contents, cross-references, indexes, etc.), while XSL 1.0 makes complex document formatting possible through the use of formatting objects and properties. In addition, to providing more sophisticated screen presentation, XSL 1.0 provides for the formatting of paged media that promises to make professional printing capabilities and functions possible from XML source documents. One can now have documents and data stored in XML, and be able to specify how to format and render them and produce versions for both Web rendering and for print medi using a single stylesheet language.. Note: A Word about XSL and CSS: In this writer's opinion, it will be quite interesting to see if commercial products embrace XSL and provide capabilities to easily develop XSL stylesheets. Will any browser directly display XSL formatted XML? In order to realize the promise of XSL, a single stylesheet language both for the Web and for print, we need to see products for both emerge that use the same subset of XSL. Without this sort of software support for the standard, the true value of XSL may remain a promise! W3C Announces XML Infoset as a New RecommendationOn October 24, 2001, W3C released the XML Information Set (Infoset) as a Recommendation. XML Infoset was produced by the XML Core Working Group. This recommendation defines a set of eleven types of information items for XML Documents. This information set is to be used in other specifications that refer to the information in a well-formed XML document. For example, XML Infoset is important to specifications such as XSLT, XML Schema and XML Linking, which themselves are expressed as a well-formed XML document. The XML Infoset does not attempt to be exhaustive, but rather specifies items that are required for current and anticipated specifications. Likewise XML Infoset does not specify a minimum set of information that must be returned by an XML processor. An information item is an abstract description of some part of an XML document: each information item has a set of associated named "properties." The terms "information set" and "information item" are much like the generic terms "tree" and "node", when they are used in computing. The terms "information set" and "information item" are used in XML Infoset to reduce possible confusion with other specific data models. Information items are not intended to map directly to the nodes of the DOM or the "tree" and "nodes" of the XPath data model. Information items specified within XML Infoset include:
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