I'm trying to do something similar (with a database markup).  I can see
how to check if it is a string node, but I also want to check for when it
is not.  I am matching against a list of objects and would like to
display the element contents, or 'NULL' if it has no string content.  My
(incorrect) attempt is this...

   <xsl:if test="string(.)">
    <xsl:value-of select="."/>
   </xsl:if>
   <xsl:if test="not(string(.))">
    NULL
   </xsl:if>

Thanks,
Steve

Kay Michael wrote:

> > I want to have my XSL stylesheet evaluate to see if a tag
> > exists or the value is blank. How do I do this using <xsl:if> or
> <xsl:when> ?
> >
> To test if the element exists:
>
> <xsl:template match="book">
> <xsl:if test="author">
>
> To test if the element exists and is non-empty:
>
> <xsl:template match="book">
> <xsl:if test="string(author)">
>
> Mike Kay
>
>  XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list