RE: [xsl] Non-existing node

Subject: RE: [xsl] Non-existing node
From: "Michael Kay" <mhkay@xxxxxxxxxxxx>
Date: Mon, 17 Sep 2001 14:09:40 +0100
> In fact, comparing two empty node-sets to each other also gives false.
>
> Ok, but the parser has to compare against something, so my question is
> if there's any reserved word or something to refer to an
> empty-nodeset.
> Let's say the reserved word is "ENS" (Empty Node Set), that
> way you could
> write something like this:
>
> 	<xsl:if test="Parent/MyNode=ENS">...</xsl:if>
>
"=" doesn't compare the node-set with anything, it compares each node in the
node-set individually, and returns true if any of the comparisons is true.

To test whether a node-set Parent/MyNode is empty, just do

<xsl:if test="Parent/MyNode">: converting a node-set to a boolean returns
true if the node-set is non-empty.

There's no reserved word to refer to an empty node-set; if you need to write
an expression that represents an empty node-set, try:

<xsl:variable name="empty" select="/.."/>

Mike Kay


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


Current Thread