lfs-book-zh_CN/stylesheets/lfs-xsl/docbook-xsl-1.78.1/params/preferred.mediaobject.role.xml

<refentry xmlns="http://docbook.org/ns/docbook"
          xmlns:xlink="http://www.w3.org/1999/xlink"
          xmlns:xi="http://www.w3.org/2001/XInclude"
          xmlns:src="http://nwalsh.com/xmlns/litprog/fragment"
          xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
          version="5.0" xml:id="preferred.mediaobject.role">
<refmeta>
<refentrytitle>preferred.mediaobject.role</refentrytitle>
<refmiscinfo class="other" otherclass="datatype">string</refmiscinfo>
</refmeta>
<refnamediv>
<refname>preferred.mediaobject.role</refname>
<refpurpose>Select which mediaobject to use based on
this value of an object's <tag class="attribute">role</tag> attribute.
</refpurpose>
</refnamediv>

<refsynopsisdiv>
<src:fragment xml:id="preferred.mediaobject.role.frag">
<xsl:param name="preferred.mediaobject.role"/>
</src:fragment>
</refsynopsisdiv>

<refsection><info><title>Description</title></info>

<para>A mediaobject may contain several objects such as imageobjects.
If the parameter <parameter>use.role.for.mediaobject</parameter> is
non-zero, then the <literal>role</literal> attribute on
<tag>imageobject</tag>s and other objects within a
<tag>mediaobject</tag> container will be used to select which object
will be used.  If one of the objects has a role value that matches the
<parameter>preferred.mediaobject.role</parameter> parameter, then it
has first priority for selection.  If more than one has such a role
value, the first one is used.
</para>
<para>
See the <parameter>use.role.for.mediaobject</parameter> parameter
for the sequence of selection.</para>
</refsection>
</refentry>