RE: navigation, TEI

Hi,

> I'm working on extending the TEI xsl stylesheet set with a more
> complex 'prev-next' navigation bar. For the linking i need two
> parameters: the text of the link, and the id of the link.
> I use a template to get the appropriate node:
> 
> <xsl:template name="getPrev">
>   <xsl:variable name="nodeSet">
>     <xsl:text>self::div0 | self::div1 | self::div2 | 
> self::div3 | self::div4</xsl:text>
>   </xsl:variable>

Here you're binding $nodeSet to a Result Tree Fragment and…
 
>   <xsl:choose>
>     <xsl:when test="(preceding-sibling::*[$nodeSet]/head)[last()]">

… here if will always return true. Either copy/paste the $nodeSet text into every place where it's used or use an entity instead of a variable.

>       <xsl:copy-of select="preceding::*[$nodeSet]/head[last()]" />
>     </xsl:when>
>     <xsl:when test="(ancestor::*[$nodeSet]/head)[last()]">
>       <xsl:copy-of select="ancestor::*[$nodeSet]/head[last()]" />

Note here that the test pattern and the copy expression do not select/match the same nodes, just like in the previous when block if the axes were the same.

>     </xsl:when>
>     <xsl:otherwise></xsl:otherwise>
>   </xsl:choose>
> </xsl:template>
> 
> and i call this with:
> <xsl:variable name="previous">
>   <xsl:call-template name="getPrev" />
> </xsl:variable>

And again, you're binding $previous to a RTF.

> but as i would like to get the id of the node the following 
> code doesn't work:
> 
>   <xsl:variable name="previousID">
>     <xsl:value-of select="generate-id( $previous )" />
>   </xsl:variable>
> 
> with the xsl processor saying: 'generate-id() : invalid arg 
> expecting a node-set'
> So i have to write another template (getPrevID) with the only 
> difference of the selection:
>   'select="generate-id( ... )"'
> 
> and the xpath expression
>   (preceding-sibling::*[$nodeSet]/head)[last()]
> is the same than this:
>   (preceding-sibling::*/head)[last()]
> the $nodeSet variable doesn't work at this situation.

How about

  <xsl:template name="getPrevID">
    <xsl:choose>
      <!--here you don't need to test for the last, because it will be true even if you have just one div# head -->
      <xsl:when test="preceding-sibling::*[self::div0 | self::div1 | self::div2 | self::div3 | self::div4]/head">
        <xsl:value-of select="generate-id(preceding::*[self::div0 | self::div1 | self::div2 | self::div3 | self::div4]/head[last()])" />
      </xsl:when>
      <xsl:when test="ancestor::*[self::div0 | self::div1 | self::div2 | self::div3 | self::div4]/head">
        <xsl:value-of select="generate-id(ancestor::*[self::div0 | self::div1 | self::div2 | self::div3 | self::div4]/head[last()])" />
      </xsl:when>
    </xsl:choose>
  </xsl:template>

Cheers,

Jarno - Cenobita: Slaves