    | DocBook: The Definitive Guide Version 0.0.1 (Alpha) |
| | DocBook: The Definitive Guide Version 0.0.1 (Alpha) |
$Revision: 1.3 $
$Date: 2002/06/12 11:18:43 $
xref — A cross reference to another part of the document
xref ::= EMPTY
Common attributes
Name | Type | Default |
| linkend | IDREF | Required |
| endterm | IDREF | None |
The XRef element forms a cross-reference from the location of the XRef to the element to which it points. Unlike Link and the other cross-referencing elements, XRef is empty. The processing system has to generate appropriate cross-reference text for the reader.
If the Endterm attribute is specified, the content of the element pointed to by Endterm must be used as the text of the cross-reference, otherwise it is up to the application to generate appropriate cross reference text from the element pointed to by Linkend.
If the object pointed to has a specified XRefLabel, that should be used as the cross-reference text.
These elements contain xref: attribution, bibliomisc, citetitle, emphasis, entry, lineannotation, link, literallayout, para, phrase, programlisting, quote, subtitle, term, title, titleabbrev, ulink.
Endterm points to the element whose content is to be used as the text of the link.
Linkend points to the target of the cross reference.
Consider the following example:
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
<book><title>An Example Book</title>
<chapter id="ch01"><title>XRef Samples</title>
<para>
This paragraph demonstrates several features of
<sgmltag>XRef</sgmltag>.
</para>
<itemizedlist>
<listitem><para>A straight link generates the
cross-reference text: <xref linkend="ch02"/>.
</para></listitem>
<listitem><para>A link to an element with an
<sgmltag class="attribute">XRefLabel</sgmltag>:
<xref linkend="ch03"/>.
</para></listitem>
<listitem><para>A link with an
<sgmltag class="attribute">EndTerm</sgmltag>:
<xref linkend="ch04" endterm="ch04short"/>.
</para></listitem>
</itemizedlist>
</chapter>
<chapter id="ch02">
<title>The Second Chapter</title>
<para>Some content here</para>
</chapter>
<chapter id="ch03" xreflabel="Chapter the Third">
<title>The Third Chapter</title>
<para>Some content here</para>
</chapter>
<chapter id="ch04">
<title>The Fourth Chapter</title>
<titleabbrev id="ch04short">Chapter 4</titleabbrev>
<para>Some content here</para>
</chapter>
</book>One reasonable rendering for the content of the first chapter of this book is the following:
This paragraph demonstrates several features of XRef.
A straight link generates the cross-reference text: Chapter 2, “The Second Chapter”
A link to an element with an XRefLabel: Chapter the Third.
A link with an EndTerm: Chapter 4.
Of course, in an online system, these references would also be links to the appropriate chapters.