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<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
<article>
  <title>The SCons Docbook tool</title>
  <articleinfo>
    <author>
      <surname>Dirk Baechle</surname>
    </author>
    <pubdate>2010-12-30</pubdate>
  </articleinfo>
<section id="basics"><title>Basics</title>
<para>This tool tries to make working with Docbook in SCons a little easier.
It provides several toolchains for creating different output formats,
like HTML or PDF. Contained in the package is
a distribution of the Docbook XSL stylesheets as of version 1.76.1.
As long as you don't specify your own stylesheets for customization (see <link linkend="stylesheet">Selecting stylesheet</link>),
these official versions are picked as default...which should reduce
the inevitable setup hassles for you.
</para>
<para>Implicit dependencies to images and XIncludes are detected automatically
if you meet the HTML requirements (see <link linkend="requirements">Requirements</link>). The additional
stylesheet <literal>utils/xmldepend.xsl</literal> by Paul DuBois is used for this purpose.
</para>
<para>Note, that there is no support for XML catalog resolving offered! This tool calls
the XSLT processors and PDF renderers with the stylesheets you specified, that's it.
The rest lies in your hands and you still have to know what you're doing when
resolving names via a catalog.
</para>
<section id="install"><title>Install</title>
<para>Installing it, requires you to copy (or, even better: checkout) the contents of the
package's <literal>docbook</literal> folder to
</para>
<orderedlist><listitem><para><quote><literal>/path_to_your_project/site_scons/site_tools/docbook</literal></quote>, if you need the Docbook Tool in one project only, or
</para>
</listitem>
<listitem><para><quote><literal>~/.scons/site_scons/site_tools/docbook</literal></quote>, for a system-wide installation under your current login.
</para>
</listitem>
</orderedlist>
<para>For more infos about this, please refer to
</para>
<itemizedlist><listitem><para>the SCons User's Guide, chap. 19.7 "Where to put your custom Builders and Tools" and
</para>
</listitem>
<listitem><para>the SCons Tools Wiki page at <ulink url="https://github.com/SCons/scons/wiki/ToolsIndex">http://github.com/SCons/scons/wiki/ToolsIndex</ulink>.
</para>
</listitem>
</itemizedlist>
</section>
<section id="activation"><title>How to activate</title>
<para>For activating the tool "docbook", you have to add its name to the Environment constructor,
like this
</para>
<screen>env = Environment(tools=['docbook'])
</screen>
<para>On its startup, the Docbook tool tries to find a required <literal>xsltproc</literal> processor, and
a PDF renderer, e.g. <literal>fop</literal>. So make sure that these are added to your system's environment
<literal>PATH</literal> and can be called directly, without specifying their full path.
</para>
</section>
<section id="requirements"><title>Requirements</title>
<para>For the most basic processing of Docbook to HTML, you need to have installed
</para>
<itemizedlist><listitem><para>the Python <literal>lxml</literal> binding to <literal>libxml2</literal>, or
</para>
</listitem>
<listitem><para>the direct Python bindings for <literal>libxml2/libxslt</literal>, or
</para>
</listitem>
<listitem><para>a standalone XSLT processor, currently detected are <literal>xsltproc</literal>, <literal>saxon</literal>, <literal>saxon-xslt</literal>
and <literal>xalan</literal>.
</para>
</listitem>
</itemizedlist>
<para>Rendering to PDF requires you to have one of the applications <literal>fop</literal>, <literal>xep</literal> or <literal>jw</literal>
installed.
</para>
</section>
</section>
<section id="process"><title>Processing documents</title>
<para>Creating a HTML or PDF document is very simple and straightforward. Say
</para>
<screen>env = Environment(tools=['docbook'])
env.DocbookHtml('manual.html', 'manual.xml')
env.DocbookPdf('manual.pdf', 'manual.xml')
</screen>
<para>to get both outputs from your XML source <literal>manual.xml</literal>. As a shortcut, you can
give the stem of the filenames alone, like this:
</para>
<screen>env = Environment(tools=['docbook'])
env.DocbookHtml('manual')
env.DocbookPdf('manual')
</screen>
<para>and get the same result. Target and source lists are also supported:
</para>
<screen>env = Environment(tools=['docbook'])
env.DocbookHtml(['manual.html','reference.html'], ['manual.xml','reference.xml'])
</screen>
<para>or even
</para>
<screen>env = Environment(tools=['docbook'])
env.DocbookHtml(['manual','reference'])
</screen>
<important><para>Whenever you leave out the list of sources, you may not specify a file extension! The
Tool uses the given names as file stems, and adds the suffixes for target and source files
accordingly.
</para>
</important>
<para>The rules given above are valid for the Builders <literal>DocbookHtml</literal>, <literal>DocbookPdf</literal>,
<literal>DocbookSlidePdf</literal> and <literal>DocbookXInclude</literal>. For the <literal>DocbookMan</literal> transformation you
can specify a target name, but the actual output names are automatically set from
the <literal>refname</literal> entries in your XML source.
</para>
<para>Please refer to <link linkend="chunked">the section Chunked output</link> for more infos about the other Builders.
</para>
</section>
<section id="stylesheet"><title>Selecting your own stylesheet</title>
<para>If you want to use a specific XSL file, you can set the additional <literal>xsl</literal> parameter to your
Builder call as follows:
</para>
<screen>env.DocbookHtml('other.html', 'manual.xml', xsl='html.xsl')
</screen>
<para>Since this may get tedious if you always use the same local naming for your customized XSL files,
e.g. <literal>html.xsl</literal> for HTML and <literal>pdf.xsl</literal> for PDF output, a set of variables for setting the
default XSL name is provided. These are:
</para>
<screen>DOCBOOK_DEFAULT_XSL_HTML
DOCBOOK_DEFAULT_XSL_HTMLCHUNKED
DOCBOOK_DEFAULT_XSL_HTMLHELP
DOCBOOK_DEFAULT_XSL_PDF
DOCBOOK_DEFAULT_XSL_MAN
DOCBOOK_DEFAULT_XSL_SLIDESPDF
DOCBOOK_DEFAULT_XSL_SLIDESHTML
</screen>
<para>and you can set them when constructing your environment:
</para>
<screen>env = Environment(tools=['docbook'],
                  DOCBOOK_DEFAULT_XSL_HTML='html.xsl',
                  DOCBOOK_DEFAULT_XSL_PDF='pdf.xsl')
env.DocbookHtml('manual') # now uses html.xsl
</screen>
</section>
<section id="chunked"><title>Chunked output</title>
<para>The Builders <literal>DocbookHtmlChunked</literal>, <literal>DocbookHtmlhelp</literal> and <literal>DocbookSlidesHtml</literal>
are special, in that:
</para>
<orderedlist><listitem><para>they create a large set of files, where the exact names and their number depend
on the content of the source file, and
</para>
</listitem>
<listitem><para>the main target is always named <literal>index.html</literal>, i.e. the output name for the
XSL transformation is not picked up by the stylesheets.
</para>
</listitem>
</orderedlist>
<para>As a result, there is simply no use in specifying a target HTML name.
So the basic syntax for these builders is:
</para>
<screen>env = Environment(tools=['docbook'])
env.DocbookHtmlhelp('manual')
</screen>
<para>Only if you use the <literal>root.filename</literal> (<literal>titlefoil.html</literal> for slides) parameter in
your own stylesheets you have to give the new target name. This ensures that the
dependencies get correct, especially for the cleanup via <quote><literal>scons -c</literal></quote>:
</para>
<screen>env = Environment(tools=['docbook'])
env.DocbookHtmlhelp('mymanual.html','manual', xsl='htmlhelp.xsl')
</screen>
<para>Some basic support for the <literal>base.dir</literal> is added (this has not been properly tested
with variant dirs, yet!). You can add the <literal>base_dir</literal> keyword to your Builder
call, and the given prefix gets prepended to all the created filenames:
</para>
<screen>env = Environment(tools=['docbook'])
env.DocbookHtmlhelp('manual', xsl='htmlhelp.xsl', base_dir='output/')
</screen>
<para>Make sure that you don't forget the trailing slash for the base folder, else
your files get renamed only!
</para>
</section>
<section id="builders"><title>All builders</title>
<para>A simple list of all builders currently available:
</para>
<variablelist><varlistentry><term>DocbookHtml
</term>
<listitem><para>Single HTML file.
</para>
</listitem>
</varlistentry>
<varlistentry><term>DocbookHtmlChunked
</term>
<listitem><para>Chunked HTML files, with support for the <literal>base.dir</literal> parameter. The <literal>chunkfast.xsl</literal>
file (requires "EXSLT") is used as the default stylesheet.
</para>
</listitem>
</varlistentry>
<varlistentry><term>DocbookHtmlhelp
</term>
<listitem><para>Htmlhelp files, with support for <literal>base.dir</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry><term>DocbookPdf
</term>
<listitem><para>PDF output.
</para>
</listitem>
</varlistentry>
<varlistentry><term>DocbookMan
</term>
<listitem><para>Man pages.
</para>
</listitem>
</varlistentry>
<varlistentry><term>DocbookSlidesPdf
</term>
<listitem><para>Slides in PDF format.
</para>
</listitem>
</varlistentry>
<varlistentry><term>DocbookSlidesHtml
</term>
<listitem><para>Slides in HTML format, with support for <literal>base.dir</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry><term>DocbookXInclude
</term>
<listitem><para>Can be used to resolve XIncludes in a preprocessing step.
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section id="more"><title>Need more?</title>
<para>This work is still in a very basic state and hasn't been tested well
with things like variant dirs, yet. Unicode problems and poor performance
with large input files may occur. There will definitely arise the need for
adding features, or a variable. Let us know if you can think of a nice
improvement or have worked on a bugfix/patch with success. Enter your issues at the
Launchpad bug tracker for the Docbook Tool, or write to the User General Discussion
list of SCons at <literal>scons-users@scons.org</literal>.
</para>
</section>

</article>
