Re: [xsl] Creating Footnote Ids

[Wendell Piez <wapiez@xxxxxxxxxxxxxxxx>]

Hi Jeff,

At 02:15 AM 7/5/2007, you wrote:
> I have an XML document that has footnote mark-up, this can appear in 
> any level within the document. I want to create an id attribute that 
> will have a value depending on the ancestors of the footnote element.
>
> for example:
>
> <book>
>    <preface>
>       <footnote/>
>       <footnote/>
>       <footnote/>
>       <footnote/>
>    </preface>
>    <part>
>        <chapter>
>           <footnote/>
>           <footnote/>
>            <footnote/>
>        </chapter>
>        <chapter>
>           <footnote/>
>           <footnote/>
>            <footnote/>
>        </chapter>
>       <footnote/>
>       <footnote/>
>       <footnote/>
>    </part>
>    <chapter>
>       <footnote/>
>       <footnote/>
>       <footnote/>
>    </chapter>
> </book>
>
> would turn to:
>
> <book>
>    <preface>
>       <footnote id="PRE1FN1"/>
>       <footnote id="PRE1FN2"/>
>       <footnote id="PRE1FN3"/>
>       <footnote id="PRE1FN4"/>
>    </preface>
>    <part>
>        <chapter>
>           <footnote id="P1C1FN1"/>
>           <footnote id="P1C1FN2"/>
>           <footnote id="P1C1FN3"/>
>        </chapter>
>        <chapter>
>           <footnote id="P1C2FN1"/>
>           <footnote id="P1C2FN2"/>
>           <footnote id="P1C2FN3"/>
>        </chapter>
>       <footnote id="P1FN1"/>
>       <footnote id="P1FN2"/>
>       <footnote id="P1FN3"/>
>    </part>
>    <chapter>
>       <footnote id="C1FN1"/>
>       <footnote id="C1FN2"/>
>       <footnote id="C1FN3"/>
>    </chapter>
> </book>
>
> How can i do this in XSLT 2.0? I tried doing it by creating a 
> variable for the count of each ancestor but I can get it correct.

It'd be simpler, I think, to use an XSLT 1.0 technique: simply 
iterate over the ancestors to generate your id string:

<xsl:template match="footnote">
  <xsl:attribute name="id">
    <xsl:apply-templates select="ancestor-or-self::*" mode="id-generate"/>
  </xsl:attribute>
  ...
</xsl:template>

<xsl:template match="part" mode="id-generate">
  <xsl:text>P</xsl:text>
  <xsl:number/>
</xsl:template>

<xsl:template match="chapter" mode="id-generate">
  <xsl:text>C</xsl:text>
  <xsl:number/>
</xsl:template>

<xsl:template match="footnote" mode="id-generate">
  <xsl:text>FN</xsl:text>
  <xsl:number/>
</xsl:template>

etc. for other ancestors you want represented in your string

<xsl:template match="*" mode="id-generate"/>
<!-- avoids default template traversal from ancestors not otherwise matched -->

I hope that helps.

Using 2.0 you could make this more concise:

<xsl:template match="preface | part | chapter | footnote" mode="id-generate">
  <xsl:variable name="code"
    select="('PRE','P','C','FN')[index-of(('preface','part','chapter','footnote'),local-name())]"/>
  <xsl:value-of select="$code"/>
  <xsl:number/>
</xsl:template>

(untested)

Note: apply-templates always works in document order, even when the 
nodes are selected on a reverse axis, as in this case. So the nodes 
will be matched in the mode from top down, not bottom up.

Cheers,
Wendell



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Wendell Piez                            mailto:wapiez@xxxxxxxxxxxxxxxx
Mulberry Technologies, Inc.                http://www.mulberrytech.com
17 West Jefferson Street                    Direct Phone: 301/315-9635
Suite 207                                          Phone: 301/315-9631
Rockville, MD  20850                                 Fax: 301/315-8285
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