<?xml version="1.0" encoding="utf-8"?>
<!--
Hyperlinks and URLs. The content of the hyperlink element becomes the link text. All hyperlink elements have these attributes:
@url: A URL that the hyperlink links to. If no link text is provided, the URL is used as the link text.
@label: A label that the hyperlink links to. The value should be an acceptable label in both LaTeX and HTML.
@target: The target tab/window to open the hyperlink in. Only applies to (X)HTML.
-->
<stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<!--
A hyperlink with an HTTP URL and some combination of label (page anchor) and content (link text).
@url: The URL to link to. [required]
@label: The name of the anchor to link to in the URL (i.e., url#label). [optional]
@target: The target of the URL (e.g., _blank). Only relevant to (X)HTML. [optional]
-->
<template name="hyperlink" match="hyperlink[@url]">
<!--
In very rare circumstances, hyperref can get munged in such a way that it doesn't correctly escape the # character for the anchor (e.g., an \href inside a \resizebox; why? I don't know). We therefore need to escape it manually, which produces the correct output regardless. The best way to do this is construct the full URL first, then replace "#" with "\#" in (Xe)LaTeX; this also catches hyperlinks where the author has embedded the anchor in the @url attribute.
-->
<common>
<xsl:variable name="fullURL">
<xsl:value-of select="@url" />
<xsl:if test="@label">
<xsl:text>#</xsl:text>
<xsl:value-of select="@label" />
</xsl:if>
</xsl:variable>
</common>
<common formats="/latex/xelatex/">
<xsl:choose>
<!--
Just a bare URL with no link text.
-->
<xsl:when test="not( node() )">
<xsl:text>\url{</xsl:text>
<xsl:value-of select="replace( $fullURL, '#', '\\#' )" />
<xsl:text>}</xsl:text>
</xsl:when>
<xsl:otherwise>
<!--
Sometimes the hyperlink content may be explicitly split across multiple lines, separated by <br> elements. This isn't a problem in (X)HTML, but it breaks (Xe)LaTeX, because you can't include a \\ inside most macros. The solution is to explicitly process the sub-elements, and wrap appropriate hyperref macros around them, /except/ for any embedded <br> elements.
We can't just call hyperlink-internal, because we still want to process the <br> elements.
-->
<xsl:for-each select="node()">
<xsl:if test="not( self::br )">
<xsl:text>\href{</xsl:text>
<xsl:value-of select="replace( $fullURL, '#', '\\#' )" />
<xsl:text>}{</xsl:text>
</xsl:if>
<xsl:apply-templates select="." />
<xsl:if test="not( self::br )">
<xsl:text>}</xsl:text>
</xsl:if>
</xsl:for-each>
</xsl:otherwise>
</xsl:choose>
</common>
<common formats="/html/xhtml/">
<!-- We can't just call hyperlink-internal, because there may be an @target attribute. -->
<a href="{$fullURL}">
<xsl:if test="@target">
<xsl:attribute name="target">
<xsl:value-of select="@target" />
</xsl:attribute>
</xsl:if>
<xsl:choose>
<xsl:when test="not( node() )">
<code><xsl:value-of select="$fullURL" /></code>
</xsl:when>
<xsl:otherwise>
<xsl:apply-templates />
</xsl:otherwise>
</xsl:choose>
</a>
</common>
</template>
<!--
Special case: hyperlink with a label and content but no URL. These represent internal links within the document, and require different code in (Xe)LaTeX (need to use the full \hyperref macro instead of \href).
@label: The name of the label to link to (will become #label in (X)HTML). [required]
@target: The target of the URL (e.g., _blank). Only relevant to (X)HTML. [optional]
-->
<template name="hyperlink-label" match="hyperlink[@label and node() and not( @url )]">
<!-- Note: not safe to use the url package here because \url{...} is fragile. -->
<common formats="/latex/xelatex/">
<xsl:for-each select="node()">
<xsl:if test="not( self::br )">
<xsl:text>\hyperref[</xsl:text>
<xsl:value-of select="../@label" />
<xsl:text>]{</xsl:text>
</xsl:if>
<xsl:apply-templates select="." />
<xsl:if test="not( self::br )">
<xsl:text>}</xsl:text>
</xsl:if>
</xsl:for-each>
</common>
<common formats="/html/xhtml/">
<a href="#{@label}">
<xsl:if test="@target">
<xsl:attribute name="target">
<xsl:value-of select="@target" />
</xsl:attribute>
</xsl:if>
<xsl:apply-templates />
</a>
</common>
</template>
<!-- ERROR: hyperlink has a label, but no URL and no content. -->
<template name="empty-hyperlink-label" match="hyperlink[@label and not( node() ) and not( @url )]">
<common>
<xsl:message terminate="yes"><hyperlink> with @label and no @url must include link text.</xsl:message>
</common>
</template>
<!-- Internal parameterised hyperlink templates to be called by the likes of the empty Oracle documentation elements. -->
<template name="hyperlink-internal" match="hyperlink" mode="hyperlink-internal">
<common>
<xsl:param name="url" />
<xsl:param name="label" />
</common>
<common formats="/latex/xelatex/">
<xsl:text>\href{</xsl:text>
<xsl:value-of select="$url" />
<xsl:text>}{</xsl:text>
<xsl:apply-templates select="exsl:node-set($label)" />
<xsl:text>}</xsl:text>
</common>
<common formats="/html/xhtml/">
<a href="{$url}"><xsl:apply-templates select="exsl:node-set($label)" /></a>
</common>
</template>
<template name="empty-hyperlink-url-internal" match="hyperlink" mode="empty-hyperlink-internal">
<common>
<xsl:param name="url" />
</common>
<common formats="/latex/xelatex/">
<xsl:text>\url{</xsl:text>
<xsl:value-of select="$url" />
<xsl:text>}</xsl:text>
</common>
<common formats="/html/xhtml/">
<a href="{$url}"><code><xsl:value-of select="$url" /></code></a>
</common>
</template>
<!-- A plain URL (i.e., not necessarily a hyperlink). -->
<template name="url" match="url|uri|email|e-mail|email-address|e-mail-address">
<!--
\url in Hyperref will give us an active linke, so use \nolinkurl instead.
-->
<common formats="/latex/xelatex/">
<xsl:text>\nolinkurl{</xsl:text>
<xsl:apply-templates />
<xsl:text>}</xsl:text>
</common>
<common formats="/html/xhtml/">
<code><xsl:apply-templates /></code>
</common>
</template>
</stylesheet>
