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On 27/09/2011 09:42, Andrew Welch wrote:
On 26 September 2011 22:17, Olivier Lefevre<lefevrol@xxxxxxxxx> wrote:What is the best XPath expression that is guaranteed to return nothing? (best in the sense of simplest, always works and costs as little as possible to evaluate). I was hoping it'd be the empty string but that seems forbidden. Usual reason for wanting this is as a default value for a parameter so you can go <xsl:param name="x" select="()"/. ... <xsl:value-of select="$x/a/b"/> incidentally () is the _only_ expression that is guaranteed to return nothing and to be safe in a schema aware xslt2 processor. Other expressions that may statically be determined empty may raise an error. david ________________________________________________________________________ The Numerical Algorithms Group Ltd is a company registered in England and Wales with company number 1249803. The registered office is: Wilkinson House, Jordan Hill Road, Oxford OX2 8DR, United Kingdom. This e-mail has been scanned for all viruses by Star. The service is powered by MessageLabs. ________________________________________________________________________
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