Re: [xsl] "Tunneling" a parameter in document order

[David Carlisle <davidc@xxxxxxxxx>]

On 13/04/2012 09:31, Christian Roth wrote:
> As for the basic requirement, I tried to describe it with: "Keeping a
> global variable's value current while doing a depth-first traversal
> of a document, where the variable's value is not scoped by either the
> document's element hierarchy, nor the nesting of XSLT template
> calls."


The normal way to achieve that is to arrange that each apply templates 
only selects one node at a time, traversing in that order, passing on a 
new value of the parameter when needed.

so given
<a>
   <b><c/><b>
   <b><c/><b>
   <b><c/><b>
</a>

don't do

<xsl:template match="*">
   ... <xsl:apply-templates/>
</xsl:template>

as that will do all three <b> branches essentially 9or perhaps really) 
in parallel so you can not pass information from branch to branch, only 
down the tree.

do


<xsl:template match="*">
   ... <xsl:apply-templates 
select="(*,ancestor-or-self::*[following-sibling::*][1]/following-sibling::*)[1]/>
</xsl:template>

as that will match elements in the order
a,b1,c1,b2,c2,b3,c3
so you can pass information using parameters down that order.

David


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