Numbered bookmarks in PDF output from DITA bookmaps with and without parts - xslt

Question

I am trying to create PDF output with numbered headings using the DITA OT and a custom plugin. By default, the output contains part numbers, chapter numbers and appendix number in the headings and the TOC, but no numbers in the bookmarks. So far, I have managed to number all the remaining topics in the headings and the TOC, like so (the chapter numbers restart in every part):
bookmap
part I
chapter 1
topic 1.1
topic 1.2
chapter 2
part II
chapter 1
However, I cannot get the same numbers for the bookmarks.
I am using the following code (or override) to select the bookmarks that must be numbered:
<xsl:template match="*[contains(#class, ' topic/topic ')]" mode="bookmark">
<xsl:variable name="mapTopicref" select="key('map-id', #id)[1]"/>
<xsl:variable name="topicTitle">
<xsl:call-template name="getNavTitle"/>
</xsl:variable>
<xsl:choose>
<xsl:when test="$mapTopicref[#toc = 'yes' or not(#toc)] or
not($mapTopicref)">
<fo:bookmark>
<xsl:attribute name="internal-destination">
<xsl:call-template name="generate-toc-id"/>
</xsl:attribute>
<xsl:if test="$bookmarkStyle!='EXPANDED'">
<xsl:attribute name="starting-state">hide</xsl:attribute>
</xsl:if>
<fo:bookmark-title>
<xsl:choose>
<xsl:when test="contains($mapTopicref/#class, ' bookmap/part ')">
<xsl:call-template name="getChapterPrefix"/>
<xsl:text> </xsl:text>
</xsl:when>
<xsl:when test="contains($mapTopicref/#class, ' bookmap/appendix ')">
<xsl:call-template name="getChapterPrefix"/>
<xsl:text> </xsl:text>
</xsl:when>
<xsl:when test="contains($mapTopicref/#class, ' bookmap/chapter ')">
<xsl:call-template name="getChapterPrefix"/>
<xsl:text> </xsl:text>
</xsl:when>
</xsl:choose>
<xsl:value-of select="normalize-space($topicTitle)"/>
</fo:bookmark-title>
<xsl:apply-templates mode="bookmark"/>
</fo:bookmark>
</xsl:when>
<xsl:otherwise>
<xsl:apply-templates mode="bookmark"/>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
I am using the following code to create the numbers (derived from an example in DITA for Print):
<xsl:template name="getChapterPrefix">
<xsl:variable name="topicType">
<xsl:call-template name="determineTopicType"/>
</xsl:variable>
<xsl:variable name="partsCount">
<xsl:value-of select="count($map//*[contains(#class, ' bookmap/part')])"/>
</xsl:variable>
<xsl:variable name="containingChapter" select="ancestor-or-self::*[contains(#class, ' topic/topic')][position()=1]"/>
<xsl:variable name="id" select="$containingChapter/#id"/>
<xsl:variable name="topicChapters">
<xsl:copy-of select="$map//*[contains(#class, ' bookmap/chapter')]"/>
</xsl:variable>
<xsl:variable name="topicAppendices">
<xsl:copy-of select="$map//*[contains(#class, ' bookmap/appendix')]"/>
</xsl:variable>
<xsl:variable name="topicParts">
<xsl:copy-of select="$map//*[contains(#class, ' bookmap/part')]"/>
</xsl:variable>
<xsl:variable name="chapterNumber">
<xsl:choose>
<xsl:when test="$topicChapters/*[#id = $id]">
<xsl:choose>
<xsl:when test="$partsCount=0"> <!-- Bookmaps without parts work fine -->
<xsl:number format="1" value="count($topicChapters/*[#id =$id]/preceding-sibling::*) + 1"/>
</xsl:when>
<xsl:otherwise> <!-- This does not work yet. -->
<xsl:number format="1" value="count($topicChapters/*[#id =$id]/preceding-sibling::*) + 1"/>
</xsl:otherwise>
</xsl:choose>
</xsl:when>
<xsl:when test="$topicAppendices/*[#id = $id]">
<xsl:number format="A" value="count($topicAppendices/*[#id =$id]/preceding-sibling::*) + 1"/>
</xsl:when>
<xsl:when test="$topicParts/*[#id = $id]">
<xsl:number format="I" value="count($topicParts/*[#id =$id]/preceding-sibling::*) + 1"/>
</xsl:when>
<xsl:otherwise></xsl:otherwise>
</xsl:choose>
</xsl:variable>
<xsl:choose>
<xsl:when test="$chapterNumber != ''">
<xsl:value-of select="$chapterNumber"/>
</xsl:when>
</xsl:choose>
</xsl:template>
With this code, parts, appendices and bookmaps without parts are numbered correctly. However, for bookmaps with parts, chapters are numbered consecutively, which is inconsistent.
bookmap
part I
chapter 1
topic 1.1
topic 1.2
chapter 2
part II
chapter 3
Can anybody help me to correct this?

Answer 1

I just found a way to obtain the result I want. The piece of code that calculates the chapter number for bookmaps with parts was modified als follows:
<!-- If there's something in $topicChapters with an id that matches the id of the
context node, then I'm inside a chapter. -->
<xsl:when test="$topicChapters/*[#id = $id]">
<xsl:choose>
<xsl:when test="$partsCount=0"> <!-- Bookmaps without parts -->
<xsl:number format="1" value="count($topicChapters/*[#id =$id]/preceding-sibling::*) + 1"/>
</xsl:when>
<xsl:otherwise> <!-- Bookmaps with parts. -->
<xsl:number format="1" value="count(//*[contains(#class,' bookmap/chapter ')][#id =$id]/preceding-sibling::*)"/>
</xsl:otherwise>
</xsl:choose>
</xsl:when>
This is probably everything but elegant, but then, I'm a tech writer ...