Question

Given a source doc like so:

<A>
  <B>
    <C>item1</C>
  </B>
  <B>
    <C>item2</C>
  </B>
  <B>
    <C>item3</C>
  </B>
</A>

What XSLT can I use to product something like this:

<A>
  <B>
    <C>item1</C>
    <C>item2</C>
    <C>item3</C>
  </B>
</A>

I have tried a sheet with…

  <xsl:template match="B">
    <xsl:choose>
      <xsl:when test="count(preceding-sibling::B)=0">
        <B>
          <xsl:apply-templates select="./C"/>
          <xsl:apply-templates select="following-sibling::B"/>
        </B>
      </xsl:when>

      <xsl:otherwise>
          <xsl:apply-templates select="./C"/>
      </xsl:otherwise>

    </xsl:choose>
  </xsl:template>

but I am getting…

<A>
  <B>
    <C>item1</C>
    <C>item2</C>
    <C>item3</C>
  </B>
  <C>item2</C>
  <C>item3</C>
</A>

A second question: I have a hard time debugging XSLT. hints?

Answer 1

Simplest approach:

<xsl:template match="/A">
  <A>
    <B>
      <xsl:copy-of select=".//C" />
    </B>
  </A>
</xsl:template>

To answer the question why you see the output you see with your XSLT:

I aussume that you have a

<xsl:apply-templates select="B" />

in place. This means:

• The <xsl:template match="B"> is called three times, once for each <B>.
• For the first <B>, it does what you intend, the other times it branches right into the <xsl:otherwise>, copying the <C>s via the <xsl:template match="C"> you probably have. This is where your extra <C>s come from.
• To fix it (not that I endorse your approach), you should change it like…

…this:

<xsl:apply-templates select="B[1]" />