Question

I am trying to merge the elements from two separate web.xml files using XSLT. For example, if web-1.xml and web-2.xml are being merged, and I’m processing web-1.xml, I want all elements in web-2.xml to be added into the result, except any that already exist in web-1.xml.

In the XSLT sheet, I have loaded the document whose servlet’s are to be merged into the other document using:

<xsl:variable name="jandy" select="document('web-2.xml')"/>

I then have the following rule:

<xsl:template match="webapp:web-app">
  <xsl:copy>
    <!--  Copy all of the existing content from the document being processed  -->
    <xsl:apply-templates/>      

    <!--  Merge any <servlet> elements that don't already exist into the result  -->        
    <xsl:for-each select="$jandy/webapp:web-app/webapp:servlet">
      <xsl:variable name="servlet-name"><xsl:value-of select="webapp:servlet-name"/></xsl:variable>

      <xsl:if test="not(/webapp:web-app/webapp:servlet/webapp:servlet-name[text() = $servlet-name])">
        <xsl:copy-of select="."/>
      </xsl:if>
    </xsl:for-each>

  </xsl:copy>

</xsl:template>

The problem I’m having is getting the test in the if correct. With the above code, the test always evaluates to false, whether a servlet-name element with the given node exists or not. I have tried all kinds of different tests but with no luck.

The relevant files are available at http://www.cs.hope.edu/~mcfall/stackoverflow/web-1.xml, and http://www.cs.hope.edu/~mcfall/stackoverflow/transform.xslt (the second web-2.xml is there as well, but StackOverflow won’t let me post three links).

Answer 1

provide an anchor for the first document, just before the for-each loop:

<xsl:variable name="var" select="."/>

then, use it in your if:

<xsl:if test="not($var/webapp:servlet/webapp:servlet-name[text() = $servlet-name])">