<chapter>
<chapterinfo>
<releaseinfo role="meta">
$Id$
</releaseinfo>
<author><surname>Walsh</surname>
<firstname>Norman</firstname></author>
<copyright><year>2000</year><holder>Norman Walsh</holder>
</copyright>
</chapterinfo>
<title>The Template System</title>

<para>Some parts of the DocBook XSL Stylesheets are actually generated
using XSL Stylesheets. In particular, the formatting of title pages
is generated using a special template system. The same template system
will eventually allow you to easily customize bibliography entries and
perhaps other parts of the system as well.</para>

<para>FIXME: there needs to be more introductory/explanatory text
here!</para>

<section><title>Changing the Article Title Page</title>

<para>In order to demonstrate how this system works, let's consider
how we can use it to change the format of article title pages.</para>

<para>By default, the stylesheets print the following elements on the
article title page, in this order: <simplelist type="inline">
<member><sgmltag>title</sgmltag></member>
<member><sgmltag>subtitle</sgmltag></member>
<member><sgmltag>corpauthor</sgmltag></member>
<member><sgmltag>authorgroup</sgmltag></member>
<member><sgmltag>author</sgmltag></member>
<member><sgmltag>releaseinfo</sgmltag></member>
<member><sgmltag>copyright</sgmltag></member>
<member><sgmltag>legalnotice</sgmltag></member>
<member><sgmltag>pubdate</sgmltag></member>
<member><sgmltag>revision</sgmltag></member>
<member><sgmltag>revhistory</sgmltag></member>
<member><sgmltag>abstract</sgmltag></member>
</simplelist>. Suppose we want to put only the
<sgmltag>title</sgmltag>, <sgmltag>author</sgmltag>, and
<sgmltag>edition</sgmltag> elements on the title page, in the order
that they appear in the <sgmltag>articleinfo</sgmltag>.
</para>

<para>The <quote>hard</quote> (and wrong!) way to do it would be to
edit <filename>titlepage.templates.xsl</filename> and make the changes
by hand.</para>

<para>The easy and right way is to construct a template document that
describes the order and sequence of elements that you want:</para>

<screen><![CDATA[
<t:templates xmlns:t="http://nwalsh.com/docbook/xsl/template/1.0"
             xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
             base-stylesheet="/path/to/html/docbook.xsl">

<t:titlepage element="article" wrapper="div" class="titlepage">
  <t:titlepage-content side="recto" order="document">
    <title predicate="[1]"/>
    <author/>
    <edition/>
  </t:titlepage-content>
</t:titlepage>
</t:templates>
]]></screen>

<para>Then process this document with the
<filename>template/titlepage.xsl</filename> stylesheet. This will
produce the following somewhat cryptic stylesheet:</para>

<screen><![CDATA[
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">

<!-- This stylesheet was created by titlepage.xsl; do not edit it by hand. -->

<xsl:import href="/path/to/html/docbook.xsl"/>

<xsl:template name="article.titlepage.recto"><xsl:apply-templates mode="article.titlepage.recto.mode" select="(articleinfo/title|artheader/title|title)[1]|articleinfo/author|artheader/author|articleinfo/edition|artheader/edition"/>
</xsl:template>

<xsl:template name="article.titlepage">
  <div class="titlepage">
    <xsl:call-template name="article.titlepage.before.recto"/>
    <xsl:call-template name="article.titlepage.recto"/>
    <xsl:call-template name="article.titlepage.before.verso"/>
    <xsl:call-template name="article.titlepage.verso"/>
    <xsl:call-template name="article.titlepage.separator"/>
  </div>
</xsl:template>

</xsl:stylesheet>
]]></screen>

<para>Despite its cryptic appearance, it has the desired result.
If you want to change <emphasis>how</emphasis> the titlepage elements
are formatted (as opposed to which ones are formatted), you have to
write your own customization layer that overrides the template for
the element in question in the <quote>titlepage.mode</quote> mode.</para>
</section>

</chapter>
