Report from International Workshop on the future of the Extensible Stylesheet Language (XSL-FO) Version 2.0

18th October 2006
Heidelberg, Germany

Nearby: XML | XSL | Call for Participation

Contents

Introduction

W3C hosted a workshop in Heidelberg, Germany, to gather inspiration, needs and techniques for a future version of XSL-FO, the formatting specification of the Extensible Stylesheet Language (XSL). The W3C XSL Working Group expects that the enhancements for XSL-FO 2.0 will focus on layout-driven formatting, augmenting the content-driven layout facilities already defined.

The Workshop was chaired by Liam Quin (W3C) and Sharon Adler (IBM), and was hosted by Heidelberger Druckmaschinen AG at the Heidelberg Print Media Academy in Heidelberg, Germany.

 

Summary

There were almost forty people at the Workshop. They included implementors of XSL, documentors, educators, users, and potential users who feel they need more features before they can join our community. As a result it is clear that there is demand for an XSL 2.0, and we plan to ahead and start the technical work early next year (2007).

Specific technical areas that arose include coordination with the SVG Working Group (for example for non-rectangular page areas) and also more work on integrating MathML. The list of requirements in this Report goes into slightly more detail, but it must be stressed that the actual work done will depend to a large extent on who participates.

Participants

Sharon Adler, IBM

Anders Berglund, IBM Research

Jirka Kosek, UEP/freelance

Andrew Shellshear, CISRA

Chris Lilley, W3C

Jeremias Märki, The Apache Software Foundation

Luca Furini, University of Bologna/Apache

Geoffrey Niven, Thunderhead Ltd.

Chis Bowditch, Thunderhead Ltd.

Manfred Krüger, MID/Information Logistics

Maciej Katafiasz, Gnome

Liam Quin, W3C

Klaas Bals, Inventive Designers

Fabio Giannti, HP

Roger Gimson, HP

Bob Hopgood, Oxford Brookes University

Edward Jiang, Oracle Corporation

Manuel Strehl, University of Regensburg

Karen Myers, w3C

Tatsuo Kobayashi, Justsystems

Kumio Ohno, Justsystems

Hiloynki Chiba, Japan Association of Graphic Arts Technology

Klaus Birkenbihl, W3C

Felix Sasaki, W3C

Klaus Stevens, Stevens Printmedien-Beratung

Achim Jander, Reemers Publishing Services gmbh

Tokushige Kobayashi, Antenna House, Inc.

Shinyu Murakmi, Antenna House, Inc.

Michael Miller, Antenna House, Inc.

Roman Huditsch, LexisNexis

Holger Flörke , Doctronic

Thomas Tikwinski, W3C ED/AT

Tony Graham, Menteith Consulting

 

Vertical Text

Just Systems of Japan gave a presentation on the needs of Japanese text formatting that they believe are not currently handled by XSL-FO.

Japanese Document Layout Presentation (PDF format)

There was some discussion but mostly for clarification.

It should be made clear that there was no disagreement that XSL-FO ought to be able to meet the needs of Japanese formatting, and that any necessary changes should certainly be considered.

Some of the requested features may also be useful for other scripts.

 

Requirements

The greater part of the day was taken up by going through the original XSL-FO requirements document and asking participants to identify areas for more work. Sharon Adler of IBM led this, along with the discussions. Items in bold were of interest to more than a third of participants.

General Formatting

Absolute postion, layering and positioning; Alignment of scripts and baseline shifts; Callouts; Copyfitting (e.g. reformatting with different parameters to make text fit an available area; perhaps also the ability to supply alternate content to use when the primary content cannot be made to fit); Cropping and scaling of images (non-rectangular crop; masks to bleed them out; some of this would come from SVG); Cross-references; Drop/raised cap; Hanging punctuation; Headers/Footers (e.g. continued on next page near text instead of in footer; variable-sized header and footer region to fit to content; ability to list all markers on the page); Hyphenation; Indents; Inline keeps; Justification, word and letter spacing (characters to exclude, perhaps by Unicode class, e.g. numerals; mixing scripts and controlling spacing with justification, e.g. embedded Japanese in English text with letterspacing; force justify when the line length is within a certain range; skewing; punctuation spacing, adding space around/after punctuation); Kerning, Ligatures; Leading (including feathering); Lists with control of label spacing; Marginalia

There was also discussion of JIS 4501, which is not currently available in English; a translated version may in the future be made available to participants in the XSL Working Group.

Non-rectangular areas; Rule corners/boxes/borders (specifically rounded corners); Run-arounds; Tables (Decimal alignment; Different table-header/footers depending on whether it is the first instance of the table, dpeending on page, column, etc. Splitting tables horizontally, also with a column header that is repeated. Should be a way to keep them visually next to each other depending on binding edge Repeat top row also on second page; Two tables underneath each other, have borders collapse; Side-by-side tables)

Columns, Floats, Keeps

Column balancing, floats, e.g. relative to the page; footnotes; multiple columns with arbitrary spans)

Fonts

CSS will take font-download specification out in a separate spec. This can be used now.

Use different size for characters depending on unicode range

Access to opentype features; You can access these in InDesign: e.g. Initial swash caps, Oldstyle figures.

Abstract this away from OpenType, Graphite, GX, etc.

Units of measurement

Allow people to define units; this was supported in DSSSL; Points in XSL were copied from CSS, afterwards CSS was changed Userdefined units can be done in XSLT, e.g. using XML entities.

Colour

Add device-specific CMYK color (SVG has this);

Fills/Shading/Vignettes (also in SVG)

Masks

Opacity

Mathematics

Strong desire for more MathML/mathematics support)

Multi-column layout

currently only for regions; add support for block-containers

Remaining Issues

Although Internationalization is important, it is a guiding principle and not a feature. Similarly with Accessibility. The remaining items in the original Requirements document were not discussed in detail.

 

CSS Compatibility

Antenna House (an implementor of XSL and represented on the XSL Working Group) gave a presentation about their desire for greater compatibility between CSS, and especially the CSS 3 drafts, and XSL-FO.

This proposal has been withdrawn.

There was a discussion on CSS compatibility at another occasion during the Workshop. Everyone wanted it, but in fact there were zero votes for compatibility with 3.0, one or two votes for compatibility with CSS 2.1, and none for CSS 2.0; no-one wanted to lost backwards compatibility with XSL-FO 1.0 or 1.1 in order to improve compatibility with the CSS 3 working drafts. A sizeable minority (more than a third) wanted the normative references to CSS removed altogether.

 

Future Work

who can say?


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Lord Stanhope's Printing Press, courtesy www.fromoldbooks.org.