Re: [xsl] passing param using value-of

[Wendell Piez <wapiez@xxxxxxxxxxxxxxxx>]

Hi again,

On 2/16/2012 6:03 PM, Andrew Welch wrote:
> > > This works fine.
> > >
> > >   <xsl:call-template name="myTemplate">
> > >          <xsl:with-param name="arguments" select="preceding-sibling::*">
> > >          </xsl:with-param>
> > > </xsl:call-template>
> > >
> > > But this doesn't:
> > >
> > > <xsl:call-template name="myTemplate">
> > >          <xsl:with-param name="arguments">
> > >               <xsl:value-of select="preceding-sibling::*" />
> > >          </xsl:with-param>
> > >   </xsl:call-template>
> > >
> > > Why ? How do I use value-of to set the value of a parameter ?
> >
> > xsl:value-of generates a (single) text node. Depending on the parameter,
> > that may be okay (or maybe not), even if the cases when a text node is good
> > but a simple string is not even better are fairly rare.
>
> Don't forget in the 2nd option that it's a text node child of a
> document node, whereas in the first option (using select) it's
> sequence type is element()*  (i think)

Indeed. To spell this out:

<xsl:with-param name="arguments" select="preceding-sibling::*"/>

binds to $arguments a sequence of nodes, namely the preceding sibling 
elements.

<xsl:with-param name="arguments">
  <xsl:value-of select="preceding-sibling::*" />
</xsl:with-param>

binds to $arguments a temporary tree with a single text node, whose 
value is determined by evaluating "preceding-sibling::*".

Probably you want the first of these, not the second. But even if you 
wanted a string, not a sequence of nodes, you could specify that more 
directly and more efficiently by operating directly on the preceding 
siblings (with a function that returns a string) instead of by using 
xsl:value-of.

Cheers,
Wendell

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Wendell Piez                            mailto:wapiez@xxxxxxxxxxxxxxxx
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