Re: [xsl] Cannot use a parameter value in the group-starting-with attribute?

[Peter Desjardins <peter.desjardins.us@xxxxxxxxx>]

Thank you! That did work. Your clarification is extremely helpful.

Peter

On Fri, May 14, 2010 at 4:07 PM, David Carlisle <davidc@xxxxxxxxx> wrote:
> On 14/05/2010 20:49, Peter Desjardins wrote:
>>
>> Hi. I'm writing a 2.0 stylesheet and my processor is Saxon HE 9.2.1.1.
>> Also, I'm just starting out with XSLT.
>>
>> I am trying to create a template with parameters that will use the
>> for-each-group element. I find that I cannot use a parameter value in
>> the group-starting-with attribute.
>
> There are two problems there, one is that patterns use a restricted syntax
> compared to xpath, but more importantly parameters and variables in xpath
> hold _values_ (as they would in c or fortran) not fragments of syntax 9as
> they would in a shell scripting language)
>
> so when you go   <xsl:with-param name="starting-element" select = "h1" />
>
> the parameter does not hold the fragment of a pattern "h1" it holds the
> result of ebaluating teh expression h1 at that point, which is a possibly
> empty  sequence of h1 nodes.
>
> the this works
>
>  <xsl:for-each select = "$starting-element">
>
> but it is not (at that point) selecting h1 elements it is simply iterating
> over the list of elements that has already been selected and stored in the
> $starting-element variable.
>
> but this could not work even if it were not a syntax error
>
> <xsl:for-each-group select = "*" group-starting-with = "$starting-element">
>
> the grouping attributes need to take patterns or expressions used to filter
> the nodes selected, not take a sequence of nodes.
>
> so do not pass in a sequence of nodes, pass in a string:
>
> <xsl:with-param name="starting-element" select = "'h1'" />
>
> (note the extra quotes(
>
> then you can use that string in a pattern
>
>
> <xsl:for-each-group select = "*"
> group-starting-with = "*[name()=$starting-element]">
>
>
> David