Re: Nesting XPath predicates

On Thu, Apr 24, 2008 at 09:17:05AM +0100, Andrew Welch wrote:
> On 24/04/2008, Liam Quin <liam@xxxxxx> wrote:
> > Easier might be
> >    <xsl:template match="dataset">
> >      <xsl:variable name="sn" select="serviceName" />
> >      <xsl:value-of select="//service/[@name = $sn]/@base" />
> >    </xsl:template>
> 
> It is easier to use a variable when you're learning, but this is what
> the current() function is for:

Good point.

> //service[@name = current()/serviceName]

That will work in the given example, but stops working if you put
that line inside a for-each...  or more precisely works differently :-)
so it's fragile, and not a technique that people can build on well.

> Ultimately though, you should use a key here:
> <xsl:key name="service-by-name" match="service" use="@name"/>
[...]
> key('service-by-name', serviceName)

That's probably a better solution.

Best,

Liam

-- 
Liam Quin, W3C XML Activity Lead, http://www.w3.org/People/Quin/
http://www.holoweb.net/~liam/ * http://www.fromoldbooks.org/