|Subject:||Re: DOCBOOK-APPS: How to structure XSL stylesheets for chunking andnon-chunking|
|From:||Bob Stayton (bo...@caldera.com)|
|Date:||Jul 30, 2001 4:40:58 pm|
From: Dan York <dyo...@e-smith.com>
Question for those of you working with XSL stylesheets.... for both my work here at e-smith/Mitel and also some of the stuff I do with the Linux Documentation Project, I need to generate both chunked and non-chunked HTML files from various DocBook files and I need a customization layer to modify certain settings in Norm's XSL stylesheets.
With SGML/DSSSL, it seems chunking was handled by the *processor*, so we all simply passed (open)jade the "-V nochunks" option when we did NOT want chunking. The DSSSL customization layer could work for both.
With XML/XSL, chunking is handled by the *stylesheet*, so there is now a need for two stylesheets - one for chunking and one for not. However, basically everything in the two stylesheets is the same. What is different is whether the stylesheet calls Norm's 'html/docbook.xsl' (non-chunking) or 'html/chunk.xsl' (chunking).
So the question really is - how do you structure a customization layer to sit on top of Norm's stylesheets?
The solution I have come up with actually uses *three* stylesheets.
I put all my customizations in an XSL stylesheet called 'e-smith-common.xsl'. This stylesheet does NOT do an <xsl:import> to Norm's XSL stylesheets. It just has all my customizations.
I then have two other stylesheets. One is called simply 'e-smith.xsl' and has the contents:
<?xml version="1.0"?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:import href="/usr/share/sgml/docbook-xsl-1.41/html/docbook.xsl"/> <xsl:import href="e-smith-common.xsl"/>
The other stylesheet, 'e-smith-chunk.xsl', is the same as the above except that it imports 'chunk.xsl' instead of 'docbook.xsl'. Both of these essentially import the appropriate XSL file from Norm and then import e-smith-common.xsl. FYI, I used <xsl:import> instead of <xsl:include> in case I later decided that I wanted to override e-smith-common.xsl in one or the other of these files.
So to use them, I just call the appropriate stylesheet. To generate a single page:
$ xsltproc -o sample.html /usr/share/sgml/e-smith.xsl sample.xml
To generate multiple pages:
$ xsltproc /usr/share/sgml/e-smith-chunk.xsl sample.xml
It all works fine, and there is no difference between the files generated this way and those I generated from my single larger stylesheets before.
So I have a system that works... why I am asking the question? Well, does anyone have a better way to do this? Is there any way to NOT have to have two separate stylesheets for chunking or non-chunking? Is there a way I can have *one* call and call it differently?
Or is the solution I have come up with the best way to do it?
Any thoughts or suggestions are welcome.
I came up with essentially the same solution once I realized you cannot do conditional imports in XSL. I'll also be curious to hear of other solutions.
In the current architecture of the DocBook stylesheets, chunking itself is a customization layer. I believe it would be possible to rewrite the main stylesheets to implement the chunk/no-chunk behavior based on a global parameter and proper attention to XSL modes. Perhaps Norm can comment on why he did it as a customization layer.
bobs Bob Stayton 400 Encinal Street Publications Architect Santa Cruz, CA 95060 Technical Publications voice: (831) 427-7796 Caldera International, Inc. fax: (831) 429-1887 email: bo...@caldera.com