XSLT create node name from variable

Question

When I have these two variables

<xsl:variable name="a" select="'Total'" />
<xsl:variable name="b" select="'500'" />

I would like create a node with the name of variable 'a' and its content from variable 'b'. I have to use xsltproc with XSLT 1.0 and a couple of EXSLT extensions (node-set amongst them) so I have kind of achieved part of it:

<xsl:template match="/">
  <xsl:variable name="x" >
    &lt;<xsl:value-of  select="$a" />&gt;
        <xsl:value-of  select="$b" />
    &lt;/<xsl:value-of  select="$a" />&gt;
  </xsl:variable>
  <xsl:value-of disable-output-escaping="yes" select="$x" />
</xsl:template>

indeed puts out this (I don't care about whitespace for the moment):

<?xml version="1.0"?>

    <Total>
        500
    </Total>

But: I want to use variable 'x' as a node set in order to further manipulate it (of course my real life example is more complex). What I did was transform it into a node-set (using exslt.org/common), that seems to work but accessing the contents does not.

  <xsl:variable name="nodes" select="common:node-set($x)" />
  <xsl:value-of select="$nodes/Total" />

leads to nothing. I would have expected '500' since $nodes/Total should be a valid XPATH 1.0 expression. Obviously I'm missing something. I guess the point is that the dynamic creation of the node name with <...> does not really create a node but just some textual output so how can I achieve a true node creation here?

Solution

This transformation:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:ext="http://exslt.org/common" exclude-result-prefixes="ext">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>
 <xsl:variable name="a" select="'Total'" />
 <xsl:variable name="b" select="'500'" />


 <xsl:template match="/*">
  <xsl:variable name="rtfX">
    <xsl:element name="{$a}">
      <xsl:value-of select="$b"/>
    </xsl:element>
  </xsl:variable>

  <xsl:value-of select="ext:node-set($rtfX)/Total"/>
 </xsl:template>
</xsl:stylesheet>

when applied on any XML document (not used), produces the wanted, correct result:

500

Comments

[Andreas]

Excellent (as ususal should I say), I could apply this to my real problem, I had played with xsl:element but hadn't figured out the braces, thanks.

[Andreas]

Done, I'm still new on stackoverflow :-) I cannot vote though since I don't have enough 'reputation' yet.

[Dimitre Novatchev]

@Andreas, NP, This is what SO is for -- all of us are learning something new every day :)