XSL Working Group Charter

Scope

XSL consists of three main components, a transformation language known as XSLT, an expression language for addressing parts of XML documents, known as XPath, and a vocabulary of formatting objects with their associated formatting properties, known as XSL-FO.

This charter defines the next phase in the continuing development of XSL. Both XSLT Version 1.0 and XPath Version 1.0 were published as W3C Recommendations in November 1999. XSL Formatting Objects became a W3C Recommendation in October 2001.

XSLT 2.0, XPath 2.0, and other related specifications were published as Candidate Recommendations on 3 November 2005. XSL 1.1 was published as a Candidate Recommendation on 20 February 2006.

Under this charter, the XSL Working Group will

• complete work on XSLT 2.0;
• continue our joint work with the XML Query Working Group to complete XPath 2.0 and the related set of specifications (listed below) and prepare their follow-on specifications, if necessary;
• complete work on XSL Formatting Objects (XSL) 1.1;
• prepare for a new version of XSL Formatting Objects (XSL 2.0); the goal is to cope with those requirements in the original requirements document (from the first charter period) which are not yet addressed by the existing versions. This includes general nested regions, non-rectangular areas, and other styling decisions based upon consideration of layout properties (as opposed to content).
• process error reports and issue corrigenda for the existing versions of specifications prepared by this Working Group.

XSLT and XPath

XSLT 2.0 is a language for transforming XML documents into other XML documents; it is intended to be used in conjunction with XPath 2.0. A transformation expressed in XSLT describes rules for transforming one or more source trees into one or more result trees. A transformation is specified through a set of template rules. The structure of result trees can be completely different from the structure of the source trees. In constructing a result tree, nodes from the source trees can be filtered and reordered, and arbitrary structure and content may be added. This mechanism allows a stylesheet to be applicable to a wide variety of source trees that have similar tree structures.

An important requirement for XSLT 2.0 and XPath 2.0 is to provide schema-awareness, so that simple datatypes and complex types defined using XML Schema may be visible to processors. It is also important for XSLT transformations to take place without requiring schema-awareness and validation.

A series of working drafts of both XPath 2.0 and XSLT 2.0 have been published, beginning in December 2001. For XSLT, major differences from the 1.0 versions are summarized in Appendix K of the XSLT 2.0 specification. For XPath 2.0, Appendix H provides a summary of the main areas of incompatibility between XPath 2.0 and XPath 1.0.

XSL Formatting Objects

The XSL Working Group moved the XSL 1.0 specification of formatting objects to Recommendation on 15 October 2001.

For the period of this new charter, the XSL Working Group will continue to maintain the XSL Recommendation, progress XSL 1.1 to Recommendation, and develop a version 2.0 of XSL formatting objects.

Success Criteria

The Working Group expects to demonstrate at least 2 interoperable implementations of all required and optional features before requesting to advance to Proposed Recommendation.