Re: More efficient way than following-sibling?

On Wednesday 20 March 2002 11:45, Michael Glick (B) wrote:
> I am trying to find a more efficient way to determine if a node has
> siblings, and then access the next sibling.
>
> Currently, I am running the following XSLT code:
>
> <xsl:if test="$TheNode/following-sibling::node()">
> ?<xsl:call-template name="GenericTemplate">
> ? <xsl:with-param name="TheNode"
> select="$TheNode/following-sibling::*[1]"/> </xsl:call-template>
> </xsl:if>
>
> However, this is very expensive, when it comes to large XML documents.

You might try using the same test in the xsl:if as you use for the select in 
the xsl:with-param.  Perhaps the xsl:if is building a list of all of the 
following-sibling::node()s, even though in order to do that test you would 
only have to check that there is one following-sibling::node().

Also, I wonder why you test for node() in the xsl:if, and use * in the 
xsl:with-param.

<xsl:if test="$TheNode/following-sibling::*[1]">
 <xsl:call-template name="GenericTemplate">
  <xsl:with-param name="TheNode" select="$TheNode/following-sibling::*[1]"/>
 </xsl:call-template>
</xsl:if>

If your processor isn't smart enough to only find the first following-sibling 
in the xsl:if, then the [1] will force it to do that.  Probably this is 
what's slowing you down in large documents.

Changing the node() to a * will also help in the future (or today?) with 
processors that can re-use the result of the first XPath expression when it 
finds a second that is exactly the same.  I think that XSLTC is planning to 
do this.

Are you sure that the problem is here?  Other than the missing [1], it seems 
like this would be a fairly innocent transformation.  If can do some 
profiling on the processor, it might help show where the problem is (or show 
that this solves it).

-- 
Peter Davis
That's the true harbinger of spring, not crocuses or swallows
returning to Capistrano, but the sound of a bat on a ball.
		-- Bill Veeck

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