Re: [xsl] question on random numbers for browser XSLT

[Martin Honnen <Martin.Honnen@xxxxxx>]

Michael Kay wrote:
> > >   <xsl:template name="rand">
> > >     <xsl:param name="scale" select="6" />
> > >     <xsl:variable name="seed" />
> > >     <xsl:choose>
> > >       <xsl:when test="function-available('exsl:node-set')">
> > >         <xsl:value-of select="document(concat('/cgi-bin/rand.pl?', 
> > > $scale, '&amp;x=', generate-id(exsl:node-set($seed))))" />
> > >       </xsl:when>
> > >       <xsl:when test="function-available('msxsl:node-set')">
> > >         <xsl:value-of select="document(concat('/cgi-bin/rand.pl?', 
> > > $scale, '&amp;x=', generate-id(msxsl:node-set($seed))))" />
> > >       </xsl:when>
> > >     </xsl:choose>
> > >   </xsl:template>
> > >
> > > </xsl:stylesheet>
> > >
> > >
> > > That'll give you six random values, assuming the Perl script 
> > > recognizes the &x=Idxxxxx as cache-append garbage.
> > Interesting approach however when I test it with browsers 
> > then Firefox (3.0), Opera (9.63) and Safari (3.2) all seem to 
> > generate the same id each time that template is called:
> > http://home.arcor.de/martin.honnen/xslt/test2009072402.xml
> > (stylesheet: 
> > http://home.arcor.de/martin.honnen/xslt/test2009072402Xsl.xml)
> >
> > Only IE (tested with IE 8) generates different ids.
>
> In XSLT 1.0 (I was surprised to rediscover just now), the value of variable
> $seed is not a result tree fragment, it is a zero-length string. So I'm a
> little bit surprised that exslt:node-set() should work on it at all, and not
> particularly surprised that it should generate the same node-set each time.

The stylesheet I used for testing 
(http://home.arcor.de/martin.honnen/xslt/test2009072402Xsl.xml) does 
create a result tree fragment with some contents in xsl:variable. 
Otherwise the test case would not have worked at all with some 
implementations (Opera for instance).




--

	Martin Honnen
	http://msmvps.com/blogs/martin_honnen/