Subject: Re: [xsl] check if a node is empty From: David Carlisle <davidc@xxxxxxxxx> Date: Thu, 17 Oct 2002 16:40:54 +0100 |
> <xsl:when test="count(*)=0"> ( to check for empty child elements) > be any inefficient ?( was just thinking of other ways to do it besides the > standard ones you have suggested ) you almost never need to check against =0 in XPath as 0 and empty node sets coerce to false. If you go <xsl:when test="*" then the semantics of the language tell you it's true if there are any elements so that's all the system need check. if you go test="count(*)=0"> then the semantics of count(*) would seem to imply that the system need check exactly how many there are (which may take longer of there are 1000000001 of them. On the other hand the chances are that your system will optimise both of these expressions to some internal system-specific test-if-empty function and so it probably doesn't make any difference what you do. David _____________________________________________________________________ This message has been checked for all known viruses by Star Internet delivered through the MessageLabs Virus Scanning Service. For further information visit http://www.star.net.uk/stats.asp or alternatively call Star Internet for details on the Virus Scanning Service. XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
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