Question

I am trying to process an xml file which has several different state groups like

<root>
<childgroup>16</childgroup>
<setstate>init</setstate>
<child1>...</child1>
<child2>...</child2>
<setstate>process<setstate>
<child2>...</child2>
<child3>...</child3>
.....
<childgroup>17</childgroup>
...

What I need is actually get something like

<childgroup no="16">
  <state statename="init">
    <child1>...</child1>
    <child2>...</child2>
  </state>
  <state statename="process">
    <child2>...</child2>
    <child3>...</child3>
  </state>
</childgroup>
<childgroup no="17">
...

I’ve done simple part which is going and adding “chgrpno” attribute and stateid attribute to all childs (it makes copy-of of all elements but childgroup and state, adding the attribute to those two.

<xsl:template match="/">
  <xsl:apply-templates mode="numb"/>
</xsl:template>

This works and in the result all childs have attribute so I could regroup them in the next pass and states have numbers so I could later make same thing. But trying to follow the example of M.Kay with “temporary documents” when I try to do

<xsl:variable name="nmb">
  <xsl:apply-templates mode="numb"/>
</xsl:variable>

<xsl:template match="/">
  <xsl:copy-of select="$nmb"/>
</xsl:template>

then it just returns the original to me, and all changes which I made in the first pass are gone. So what am I doing wrong here?

I use XSLT 1.0, not XSLT 2.0 explicitly.

(edit: surely I named the variable, forgot to copy it here).

Answer 1

Here is an example how to approach the grouping with XSLT 1.0 in one step; the stylesheet

<xsl:stylesheet
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  version="1.0">

  <xsl:output indent="yes"/>

  <xsl:key name="k1" match="root/*[not(self::childgroup)]" 
    use="generate-id(preceding-sibling::childgroup[1])"/>

  <xsl:key name="k2" match="root/*[not(self::childgroup) and not(self::setstate)]"
    use="concat(generate-id(preceding-sibling::childgroup[1]), '|', generate-id(preceding-sibling::setstate[1]))"/>

  <xsl:template match="root">
    <xsl:copy>
      <xsl:apply-templates select="childgroup"/>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="childgroup">
    <childgroup no="{.}">
      <xsl:apply-templates select="key('k1', generate-id())[self::setstate]"/>
    </childgroup>
  </xsl:template>

  <xsl:template match="setstate">
    <state statename="{.}">
      <xsl:copy-of select="key('k2', concat(generate-id(preceding-sibling::childgroup[1]), '|', generate-id()))"/>
    </state>
  </xsl:template>

</xsl:stylesheet>

transforms the input sample

<root>
  <childgroup>16</childgroup>
  <setstate>init</setstate>
  <child1>...</child1>
  <child2>...</child2>
  <setstate>process</setstate>
  <child2>...</child2>
  <child3>...</child3>
  <childgroup>17</childgroup>
  <setstate>init</setstate>
  <child1>...</child1>
  <child2>...</child2>
  <setstate>process</setstate>
  <child2>...</child2>
  <child3>...</child3>
</root>

into

<root>
   <childgroup no="16">
      <state statename="init">
         <child1>...</child1>
         <child2>...</child2>
      </state>
      <state statename="process">
         <child2>...</child2>
         <child3>...</child3>
      </state>
   </childgroup>
   <childgroup no="17">
      <state statename="init">
         <child1>...</child1>
         <child2>...</child2>
      </state>
      <state statename="process">
         <child2>...</child2>
         <child3>...</child3>
      </state>
   </childgroup>
</root>