[xsl] filtering problem

[Adrian Herscu <adrian.herscu@xxxxxxxxx>]

Hi all,

Consider the following input XML file:

<?xml version="1.0" encoding="UTF-8"?>
<batch name="level1">
  <command src="1" />
  <command src="2" failed="true()" />
  <command src="3" />
  <command src="4" failed="true()" />
  <batch name="level2">
    <command src="10" />
    <command src="11" failed="true()" />
    <command src="12" />
    <batch name="level3">
      <command src="20" />
      <command src="21" failed="true()" />
      <command src="22" />
    </batch>
    <command src="30" />
    <command src="31" failed="true()" />
    <command src="32" />
  </batch>
</batch>

I need an XSL transformation that scans the top-level batch until it 
finds a command marked as failed, no matter at which internal 
batch-level it is, preserving the batch level on the report.

Currently, I have this XSL:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"; 
xmlns:xalan="http://xml.apache.org/xalan";>

  <xsl:output method="xml" indent="yes" encoding="UTF-8"
    media-type="text/xml" xalan:indent-amount="2" />

  <xsl:strip-space elements="*" />

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

  <!--
    FIXME: batches are matched even though there is a prior failed
    command or batch containing a failed command
  -->
  <xsl:template match="batch">
    <batch name="{@name}">
      <xsl:apply-templates />
    </batch>
  </xsl:template>

  <!-- match only the first failing command -->
  <xsl:template match="command[@failed=true()][1]">
    <failed-command src="{@src}" />
  </xsl:template>
</xsl:stylesheet>

which generates:

<?xml version="1.0" encoding="UTF-8"?>
<batch xmlns:xalan="http://xml.apache.org/xalan"; name="level1">
  <failed-command src="2" />
  <batch name="level2">
    <failed-command src="11" />
    <batch name="level3">
      <failed-command src="21" />
    </batch>
  </batch>
</batch>

instead of:

<?xml version="1.0" encoding="UTF-8"?>
<batch xmlns:xalan="http://xml.apache.org/xalan"; name="level1">
  <failed-command src="2" />
</batch>

Another example -- if only command[@src='21'] is marked failed, then the 
generated output should be:

<?xml version="1.0" encoding="UTF-8"?>
<batch name="level1">
  <batch name="level2">
    <batch name="level3">
      <failed-command src="21" />
    </batch>
  </batch>
</batch>

Thanks for your help,
Adrian.