Re: Implementing XPointer Resolution With saxon:evalua

Jeni Tennison wrote:
> 
> Hi Eliot,
> 
> Sorry, I should have given more clues...

Ok, here is a new version that appears to work correctly for all
possible in-document links.

Thanks for all the help.

Cheers,

Eliot

<?xml version='1.0'?>
<!-- Copyright (c) 2002 ISOGEN International 

     This style sheet serves as a reference implementation of the
XIndirect facility.
     It may be used without restriction as long as this copyright
statement is
     preserved. This software is provided AS-IS without any warranty,
express or implied.

  -->
<xsl:stylesheet version="1.0" 
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xlink="http://www.w3.org/TR/xlink"
  xmlns:xindr="http://www.isogen.com/papers/xindirection.xml"
  xmlns:xindrf="http://www.isogen.com/functions/xindirection"
  xmlns:saxon="http://icl.com/saxon"
  xmlns:func="http://exslt.org/functions"
  xmlns:fcommon="http://exslt.org/common"
  extension-element-prefixes="func xindrf"
>

<func:function name="xindrf:resolve-xpointer">
  <xsl:param name="pointer-node"/><!-- The Element node that exhibits
the XPointer to be resolved -->
  <xsl:param name="indirector-treatment">as-indirector</xsl:param>
  <xsl:variable name="indirector-treatment-str"
select="string($indirector-treatment)"/>
  <xsl:variable name="xpointer">
    <xsl:choose>
      <xsl:when test="starts-with($pointer-node/@href,'#')">
        <xsl:value-of select="substring($pointer-node/@href, 2)"/>
      </xsl:when>
      <xsl:otherwise>
        <xsl:value-of select="$pointer-node/@href"/>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:variable>

  <xsl:for-each select="$pointer-node">
    <!-- Setting the context to the pointer node so that relative URLs
are resolved
         relative to the pointer node by saxon:evaluate() -->
    <xsl:choose>
      <xsl:when test="$xpointer != ''">     
        <xsl:variable name="direct-result-set"
select="saxon:evaluate($xpointer)"/>
        <xsl:if test="string($direct-result-set) = ''">
          <xsl:message>*** XIndirect warning: XPointer '<xsl:value-of
select="$xpointer"/>' failed to address any nodes.</xsl:message>
        </xsl:if>
        <func:result
select="xindrf:resolve-indirectors($direct-result-set,
$indirector-treatment-str)"/>
      </xsl:when>
      <xsl:otherwise>
        <xsl:message>
  *** XIndirect error: $xpointer value is '' in resolve-xpointer.
          <func:result select="/.."/>
        </xsl:message>
      </xsl:otherwise>
    </xsl:choose>  
  </xsl:for-each>
</func:function>

<func:function name="xindrf:resolve-indirectors">
  <xsl:param name="pointer-node-set" select="/.."/>
  <xsl:param name="indirector-treatment">as-indirector</xsl:param>
  <xsl:variable name="indirector-treatment-str"
select="string($indirector-treatment)"/>
  <xsl:choose>
    <xsl:when test="$pointer-node-set">
      <xsl:variable name="car" select="$pointer-node-set[1]"/>
      <xsl:variable name="cdr" select="$pointer-node-set[position() &gt;
1]"/>
      <xsl:choose>
        <xsl:when test="$car[self::xindr:indirector] and 
                        ($indirector-treatment-str != 'as-resource')">
          <xsl:variable name="rns" 
                select="xindrf:resolve-xpointer($car,
$car/@indirector-treatment) |
                        xindrf:resolve-indirectors($cdr,
$indirector-treatment-str)"/>
          <func:result select="$rns"/>
        </xsl:when>
        <xsl:otherwise>
          <xsl:variable name="rest"
select="xindrf:resolve-indirectors($cdr, $indirector-treatment-str)"/>
          <xsl:variable name="rns" 
              select="$car | $rest"/>
          <func:result select="$rns"/>
        </xsl:otherwise>
      </xsl:choose>
    </xsl:when>
    <xsl:otherwise>
      <func:result select="/.."/>
    </xsl:otherwise>
  </xsl:choose>
</func:function>
</xsl:stylesheet>

-- 
W. Eliot Kimber, eliot@xxxxxxxxxx
Consultant, ISOGEN International

1016 La Posada Dr., Suite 240
Austin, TX  78752 Phone: 512.656.4139

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list