Re: [xsl] How to check if a value is numeric and add 2500 to it?

["G. Ken Holman" <gkholman@xxxxxxxxxxxxxxxxxxxx>]

At 2010-04-05 14:01 +0200, Ben Stover wrote:
> Assume I have a XML doc which might contain an optional tag with a 
> numeric value similar to
>
> <ns1:aaa>345</ns1:aaa>
>
> Now I want to check with a XSLT expression:
> - if this optional <ns1:aaa> tag exists at all

You address it with a node set expression and if the result is 
non-empty, then it exists.

If you are using XSLT 1 and you are at the parent of the element then:

  <xsl:if test="ns1:aaa">

A more explicit way in XSLT 2 would be:

  <xsl:if test="exists(ns1:aaa)">

... but the result is the same.

> - if it exists then it should be checked if the value is numeric 
> (leading and trainling blanks should be ignored. integer and 
> floating numbers should both be
> acceptable

If you are using XSLT 1 then:

  <xsl:if test="number(ns1:aaa) = number(ns1:aaa)">

... because of the property of NaN not being equal to NaN.

A more explicit way in XSLT 2 would be:

  <xsl:if test="ns1:aaa castable as xsd:float">

> - If the value is numeric then 2500 (resp. 2500.00) should be added

  <xsl:value-of select="ns1:aaa + 2500"/>

> How can I implement this logic in XSLT?

  <xsl:if test="exists(ns1:aaa)">
    <xsl:if test="ns1:aaa castable as xsd:float">
      <xsl:value-of select="ns1:aaa + 2500"/>
    </xsl:if>
  </xsl:if>

I hope this helps.

. . . . . . . . . Ken


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