<refentry id="use.role.for.mediaobject">
<refmeta>
<refentrytitle>use.role.for.mediaobject</refentrytitle>
<refmiscinfo role="type">boolean</refmiscinfo>
</refmeta>
<refnamediv>
<refname>use.role.for.mediaobject</refname>
<refpurpose>Use <sgmltag class="attribute">role</sgmltag> attribute 
value for selecting which of several objects within a mediaobject to use.
</refpurpose>
</refnamediv>

<refsynopsisdiv>
<src:fragment id='use.role.for.mediaobject.frag'>
<xsl:param name="use.role.for.mediaobject" select="1"/>
</src:fragment>
</refsynopsisdiv>

<refsect1><title>Description</title>

<para>If non-zero, the <sgmltag class="attribute">role</sgmltag> attribute on
<sgmltag>imageobject</sgmltag>s or other objects within a <sgmltag>mediaobject</sgmltag> container will be used to select which object will be
used.
</para>
<para>
The order of selection when then parameter is non-zero is:
</para>
<orderedlist>
<listitem>
    <para>If the stylesheet parameter <parameter>preferred.mediaojbect.role</parameter> has a value, then the object whose role equals that value is selected.</para>
</listitem>
<listitem>
<para>Else if an object's role attribute has a value of
<literal>html</literal> for HTML processing or
<literal>fo</literal> for FO output, then the first
of such objects is selected.
</para>
</listitem>
<listitem>
<para>Else the first suitable object is selected.</para>
</listitem>
</orderedlist>
<para>
If the value of 
<parameter>use.role.for.mediaobject</parameter>
is zero, then role attributes are not considered
and the first suitable object
with or without a role value is used.
</para>
</refsect1>
</refentry>
