From 8490d286c43e6373cc4668c754422c096f86d83f Mon Sep 17 00:00:00 2001
From: Bob Stayton <bobs@sagehill.net>
Date: Mon, 20 Jan 2014 22:36:49 +0000
Subject: [PATCH] Add support for $autolink.index.see to automatically form
 links between see and seealso index elements and primary elements in the
 index.

---
 xsl/fo/autoidx.xsl | 119 ++++++++++++++++++++++++++++++++++++++++-----
 xsl/fo/param.ent   |   1 +
 xsl/fo/param.xweb  |   2 +
 3 files changed, 111 insertions(+), 11 deletions(-)

diff --git a/xsl/fo/autoidx.xsl b/xsl/fo/autoidx.xsl
index ef0b31820..059680c08 100644
--- a/xsl/fo/autoidx.xsl
+++ b/xsl/fo/autoidx.xsl
@@ -40,6 +40,10 @@
          match="indexterm"
          use="&primary;"/>
 
+<xsl:key name="primaryonly"
+         match="indexterm"
+         use="normalize-space(primary)"/>
+
 <xsl:key name="secondary"
          match="indexterm"
          use="concat(&primary;, &sep;, &secondary;)"/>
@@ -290,6 +294,11 @@
   </xsl:variable>
 
   <fo:block>
+    <xsl:if test="$autolink.index.see != 0">
+      <xsl:attribute name="id">
+        <xsl:value-of select="concat('ientry-', generate-id())"/>
+      </xsl:attribute>
+    </xsl:if>
     <xsl:if test="$axf.extensions != 0">
       <xsl:attribute name="axf:suppress-duplicate-page-number">true</xsl:attribute>
     </xsl:if>
@@ -759,19 +768,62 @@
 </xsl:template>
 
 <xsl:template match="indexterm" mode="index-see">
-   <xsl:param name="scope" select="."/>
+  <xsl:param name="scope" select="."/>
   <xsl:param name="role" select="''"/>
   <xsl:param name="type" select="''"/>
 
-   <fo:inline>
-     <xsl:text> (</xsl:text>
-     <xsl:call-template name="gentext">
-       <xsl:with-param name="key" select="'see'"/>
-     </xsl:call-template>
-     <xsl:text> </xsl:text>
-     <xsl:value-of select="see"/>
-     <xsl:text>)</xsl:text>
-   </fo:inline>
+  <xsl:variable name="see" select="normalize-space(see)"/>
+
+  <!-- can only link to primary, which should appear before comma
+  in see "primary, secondary" entry -->
+  <xsl:variable name="seeprimary">
+    <xsl:choose>
+      <xsl:when test="contains($see, ',')">
+        <xsl:value-of select="substring-before($see, ',')"/>
+      </xsl:when>
+      <xsl:otherwise>
+        <xsl:value-of select="$see"/>
+      </xsl:otherwise>
+    </xsl:choose>
+  </xsl:variable> 
+
+  <xsl:variable name="seetarget" select="key('primaryonly', $seeprimary)[1]"/>
+
+  <xsl:variable name="linkend">
+    <xsl:if test="$seetarget">
+      <xsl:value-of select="concat('ientry-', generate-id($seetarget))"/>
+    </xsl:if>
+  </xsl:variable>
+  
+  <fo:inline>
+    <xsl:text> (</xsl:text>
+    <xsl:call-template name="gentext">
+      <xsl:with-param name="key" select="'see'"/>
+    </xsl:call-template>
+    <xsl:text> </xsl:text>
+    <xsl:choose>
+      <!-- manual links have precedence -->
+      <xsl:when test="see/@linkend or see/@xlink:href">
+        <xsl:call-template name="simple.xlink">
+          <xsl:with-param name="node" select="see"/>
+          <xsl:with-param name="content" select="$see"/>
+        </xsl:call-template>
+      </xsl:when>
+      <xsl:when test="$autolink.index.see = 0">
+         <xsl:value-of select="$see"/>
+      </xsl:when>
+      <xsl:when test="$seetarget">
+        <fo:basic-link internal-destination="{$linkend}"
+                       xsl:use-attribute-sets="xref.properties">
+          <xsl:value-of select="$see"/>
+        </fo:basic-link>
+      </xsl:when>
+      <xsl:otherwise>
+        <xsl:value-of select="$see"/>
+      </xsl:otherwise>
+    </xsl:choose>
+    <xsl:text>)</xsl:text>
+  </fo:inline>
 </xsl:template>
 
 <xsl:template match="indexterm" mode="index-seealso">
@@ -781,15 +833,60 @@
 
   <xsl:for-each select="seealso">
     <xsl:sort select="translate(., &lowercase;, &uppercase;)"/>
+
+    <xsl:variable name="seealso" select="normalize-space(.)"/>
+
+    <!-- can only link to primary, which should appear before comma
+    in seealso "primary, secondary" entry -->
+    <xsl:variable name="seealsoprimary">
+      <xsl:choose>
+        <xsl:when test="contains($seealso, ',')">
+          <xsl:value-of select="substring-before($seealso, ',')"/>
+        </xsl:when>
+        <xsl:otherwise>
+          <xsl:value-of select="$seealso"/>
+        </xsl:otherwise>
+      </xsl:choose>
+    </xsl:variable> 
+
+    <xsl:variable name="seealsotarget" select="key('primaryonly', $seealsoprimary)[1]"/>
+
+    <xsl:variable name="linkend">
+      <xsl:if test="$seealsotarget">
+        <xsl:value-of select="concat('ientry-', generate-id($seealsotarget))"/>
+      </xsl:if>
+    </xsl:variable>
+
     <fo:block>
       <xsl:text>(</xsl:text>
       <xsl:call-template name="gentext">
         <xsl:with-param name="key" select="'seealso'"/>
       </xsl:call-template>
       <xsl:text> </xsl:text>
-      <xsl:value-of select="."/>
+      <xsl:choose>
+        <!-- manual links have precedence -->
+        <xsl:when test="@linkend or @xlink:href">
+          <xsl:call-template name="simple.xlink">
+            <xsl:with-param name="node" select="."/>
+            <xsl:with-param name="content" select="$seealso"/>
+          </xsl:call-template>
+        </xsl:when>
+        <xsl:when test="$autolink.index.see = 0">
+          <xsl:value-of select="$seealso"/>
+        </xsl:when>
+        <xsl:when test="$seealsotarget">
+          <fo:basic-link internal-destination="{$linkend}"
+                         xsl:use-attribute-sets="xref.properties">
+            <xsl:value-of select="$seealso"/>
+          </fo:basic-link>
+        </xsl:when>
+        <xsl:otherwise>
+          <xsl:value-of select="$seealso"/>
+        </xsl:otherwise>
+      </xsl:choose>
       <xsl:text>)</xsl:text>
     </fo:block>
+
   </xsl:for-each>
 
 </xsl:template>
diff --git a/xsl/fo/param.ent b/xsl/fo/param.ent
index bf1536fff..a2dd5dfe7 100644
--- a/xsl/fo/param.ent
+++ b/xsl/fo/param.ent
@@ -365,3 +365,4 @@
 <!ENTITY mark.optional.procedure.steps SYSTEM "../params/mark.optional.procedure.steps.xml">
 <!ENTITY xsl1.1.bookmarks SYSTEM "../params/xsl1.1.bookmarks.xml">
 <!ENTITY show.bookmarks SYSTEM "../params/show.bookmarks.xml">
+<!ENTITY autolink.index.see SYSTEM "../params/autolink.index.see.xml">
diff --git a/xsl/fo/param.xweb b/xsl/fo/param.xweb
index 5f1b1a866..0e957b4ae 100644
--- a/xsl/fo/param.xweb
+++ b/xsl/fo/param.xweb
@@ -78,6 +78,7 @@ $Id$
 &index.preferred.page.properties;
 &index.entry.properties;
 &index.div.title.properties;
+&autolink.index.see;
 &index.number.separator;
 &index.range.separator;
 &index.term.separator;
@@ -936,6 +937,7 @@ around all these parameters.</para>
 <src:fragref linkend="mark.optional.procedure.steps.frag"/>
 <src:fragref linkend="xsl1.1.bookmarks.frag"/>
 <src:fragref linkend="show.bookmarks.frag"/>
+<src:fragref linkend="autolink.index.see.frag"/>
 
 </xsl:stylesheet>
 </src:fragment>
-- 
2.40.0