Question

I am trying to transform an XML file into an updated version.

I have the following Source XML

<?xml version="1.0" encoding="utf-8" ?>
<config>
  <section name="abc">
    <key name="key1">My Key One</key>
  </section>
  <section name="def">
    <key name="key2">My Key Two</key>
  </section>
</config>

The transformation is to look like this… however, the target actually may already look like this, so I do not want section xyz added if already exists:

<?xml version="1.0" encoding="utf-8" ?>
<config>
  <section name="abc">
    <key name="key1">My Key One</key>
  </section>
  <section name="def">
    <key name="key2">My Key Two</key>
  </section>
  <section name="xyz">
    <key name="key3">My Key Three</key>
  </section>
</config>

XSLT currently looks like this:

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" indent="yes"/>
<xsl:template match="config">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>

<xsl:template match="@*|text()|comment()|processing-instruction()">
<xsl:copy-of select="."/>
</xsl:template>

<xsl:template match="config/section">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>

<xsl:template match="config/section/key">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>

</xsl:stylesheet>

This appears to replicate what exists. How do I get it to add my missing element if it is in fact missing?

Answer 1

Try something like this:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output indent="yes"/>
  <xsl:strip-space elements="*"/>

  <xsl:template match="node()|@*">
    <xsl:copy>
      <xsl:apply-templates select="node()|@*"/>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="config">
    <xsl:copy>
      <xsl:apply-templates select="node()|@*"/>
      <xsl:if test="not(section/@name='xyz')">
        <section name="xyz">
          <key name="key3">My Key Three</key>
        </section>
      </xsl:if>
    </xsl:copy>    
  </xsl:template>

</xsl:stylesheet>