Use XSLT to convert separators into wrappers

Question

I have a piece of XML that I want to transform with XSLT (using xsltproc--so only XSLT 1.0). The original XML uses some tags as separators like this:

<container>
  <element />
  <element />
  <separator />
  <element />
  <element />
  <element />
  <separator />
  <element />
</container>

I need to transform this into a format that wraps these elements instead. So I need it to look like this:

<container>
  <wrapper>
    <element />
    <element />
  </wrapper>
  <wrapper>
    <element />
    <element />
    <element />
  </wrapper>
  <wrapper>
    <element />
  </wrapper>
</container>

I just can't seem to design a template that achieves this. Anybody out there have any thoughts?

Answer 1

This transformation:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:key name="kFollowing" match="element"
          use="generate-id(preceding-sibling::separator[1])"/>

 <xsl:template match="/*">
     <container>
       <xsl:apply-templates select=
       "element
            [generate-id()
            =
             generate-id(key('kFollowing',
                             generate-id(preceding-sibling::separator[1])
                             )[1]
                        )
             ]"/>
     </container>
 </xsl:template>

 <xsl:template match="element">
  <wrapper>
    <xsl:copy-of select=
    "key('kFollowing',
         generate-id(preceding-sibling::separator[1])
         )"/>
  </wrapper>
 </xsl:template>
</xsl:stylesheet>

when applied on the provided XML document:

<container>
    <element />
    <element />
    <separator />
    <element />
    <element />
    <element />
    <separator />
    <element />
</container>

produces the wanted, correct result:

<container>
   <wrapper>
      <element/>
      <element/>
   </wrapper>
   <wrapper>
      <element/>
      <element/>
      <element/>
   </wrapper>
   <wrapper>
      <element/>
   </wrapper>
</container>