Guy wrote:
> I have the following snippet of XSL to filter a book collection by category:
> 
> <xsl:stylesheet version="1.0"
> xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
>   <xsl:param name="categor"/>
>   <xsl:template match="/">
>       <xsl:for-each select="books/book">
>         <xsl:if test="category=$categor">
>           <!-- Show info... -->
>         </xsl:if>
>       </xsl:for-each>
>   </xsl:template>
> </xsl:stylesheet>
> 
> My question: If the categor param is zero length (i.e. no filter) then how
> do I test for this and allow all books through? In other words I would like
> the commented code in the snippet above to be executed if the categor param
> is not filled in.
> 
> Thanks!

Hi,

Specify a default value for the parameter:
<xsl:param name="categor" select="''"/>

And test for it:
<xsl:if test="$categor='' or category=$categor">

	# r

-- 
Ronan Klyne
Business Collaborator Developer
Tel: +44 (0)870 163 2555
ronan.klyne@xxxxxxxxxxx
www.groupbc.com