Re: Displaying Unique attribute value

Play the video

Subject: Re: Displaying Unique attribute value
From: Wendell Piez <wapiez@xxxxxxxxxxxxxxxx>
Date: Wed, 29 Oct 2008 10:43:21 -0400

Hi,

At 10:12 AM 10/29/2008, Syd wrote:

I think maybe I don't understand the desired input & output quite
correctly here. I would have thought something like

   <xsl:if
        test=" normalize-space( @page-num )
               !=
               normalize-space( preceding::*[@page-num][1]/@page-num )">

would do the trick. Is there something wrong with this approach that
I'm missing? Perhaps the grouping approach suggested is significantly
more efficient?

It depends on the processor, but generally, yes it is. A processor might well not have the smarts to avoid collecting all the @page-num attributes on all the preceding elements that have one, before it looks at the first. If you do this very much, that could be many checks back through the entire document.

The "grouping approach" (which is really misnamed since the essence of the Muenchian method isn't in the grouping as such, but in the analysis of distinct values, which is the harder part) will tend to be more efficient. This is because it works, in effect, by pre-indexing the tree (that's what the key does), allowing for quick retrieval.

There's no reason a processor couldn't do this by itself, or optimize the check on the preceding:: axis in some other way. For example, one can readily envision a TEI-specialized XSLT engine that would do special things with TEI input and/or recognize certain TEI-specific idioms in XSLT code, in order to do TEI things really fast. :->

Cheers,
Wendell


======================================================================
Wendell Piez                            mailto:wapiez@xxxxxxxxxxxxxxxx
Mulberry Technologies, Inc.                http://www.mulberrytech.com
17 West Jefferson Street                    Direct Phone: 301/315-9635
Suite 207                                          Phone: 301/315-9631
Rockville, MD  20850                                 Fax: 301/315-8285
----------------------------------------------------------------------
  Mulberry Technologies: A Consultancy Specializing in SGML and XML
======================================================================

Current Thread
RE: Displaying Unique attribute value, (continued) Michael Kay - 6 Oct 2008 10:33:13 -0000 Ganesh Babu N - 7 Oct 2008 04:40:19 -0000 Ganesh Babu N - 29 Oct 2008 07:05:14 -0000 Syd Bauman - 29 Oct 2008 14:12:46 -0000 Wendell Piez - 29 Oct 2008 14:59:36 -0000 <=

<- Previous	Index	Next ->
Re: Displaying Unique attribu, Syd Bauman	Thread	Re: FO Table widths - table-l, Karl Stubsjoen
Counting when using xsl:key i, Peter Sherwood	Date	RE: Extracting Unique element, Wendell Piez
	Month

PURCHASE STYLUS STUDIO ONLINE TODAY!

Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced!

Download The World's Best XML IDE!

Accelerate XML development with our award-winning XML IDE - Download a free trial today!

Subscribe in XML format

RSS 2.0
Atom 0.3

XML Editor - Download a 15 Day Free Trial Now >

See What's New in Stylus Studio >

Buy Stylus Studio - XML Editor - Now >