Re: [xsl] question about test="total[. $lt$ 10]

[Jeni Tennison <mail at jenitennison dot com>]

Hi Amy,

> <xsl:stylesheet xmlns:xsl="http://www.w3.org/TR/WD-xsl">

The best advice that we can offer is to start using XSLT rather than
this old Microsoft-specific version.  Have a look at the MSXML FAQ at
http://www.netcrucible.com/xslt/msxml-faq.htm for more details.

As for your question, the XML for the order elements look like:

<order>
2
<total>65
</total>
</order>

When an XSLT processor looks at this XML, it forms a node tree that
looks like:

+- (element) order
   +- (text) [NL]2[NL]
   +- (element) total
   |  +- (text) 65[NL]
   +- (text) [NL]

Where [NL] are line breaks.

When you evaluate the 'value' of a node, you're actually looking at
its string value.  The string value of a node is made up by
concatenating all the text node descendants of the node.

So the string value of the 'total' element is '65[NL]' which evaluates
to the number 65 when you try to compare it to another number, so
expressions like:

  total[. &lt; 20]

works OK.

The string value of the 'order' element is '[NL]2[NL]65[NL]' which
evaluates to NaN when you try to compare it to another number.  What
you want as the 'value' of the 'order' element is the value of the
first text node in the order element.  You can get that with:

  text()[1]

So, if the current node is the 'order' element (as it is in a template
matching the 'order' element or within an xsl:for-each that operates
over the 'order' elements), you can test its 'value' with:

   <xsl:choose>
      <xsl:when test="text()[1] &lt; 10">
         <hr style="color:red" />
      </xsl:when>
      <xsl:when test="text()[1] &lt; 20">
         <hr style="color:pink" />
      </xsl:when>
      <xsl:otherwise>
         <hr style="color:green" />
      </xsl:otherwise>
   </xsl:choose>

Having to use text()[1] is one of the reasons that people who use XSLT
usually encourage XML designers not to use mixed content.  If your XML
looked like:

<order>
   <value>2</value>
   <total>65</total>
</order>

then you could use:

   value &lt; 20

which is a bit neater.
   
I hope that helps,

Jeni

---
Jeni Tennison
http://www.jenitennison.com/



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