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Re: [xsl] Swing-style Glue and Struts

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James,

What you describe is, as you apparently suspect, very ambitious. It is perilously close to constraint-based, layout-driven formatting, which is still a ways out.

For example, you're bound to find that "count[ing] lines within the template match block that were copied through" will be a bear. What's a "line"? Will it be a structure in your source (say a <line> element) you can count, or will you have to resort to other means to count them?

Another problem you'll have is that HTML is *not* well-suited to support this design paradigm: you are bound to require many kluges, browser dependencies etc. if you try to get at all complex. (For example, you need to go to CSS ... still unevenly supported ... before you can get a notion of "vertical line spacing" in HTML.) Trying to teach a dog to dance, etc. (Now, *eventually* it is to be hoped that XSL-FO may do this kind of thing fairly gracefully. But not soon: let's get v.1 first. Some SVG people are beginning to make noises about constraint-based processing for their v.2. I hope they try it: it seems a natural place to take a first stab at the problem.)

Now, this is not to say the task you describe is impossible, if (as you stipulate) your "layout manager" is rudimentary enough. Just don't try to get too ambitious: go one tiny step at a time.

Just my impressions. I hope someone whose hands are deeper in the guts of the technologies is willing to weigh in. (I'm just a "user".)

Cheers,
Wendell

At 10:03 AM 8/1/01, you wrote:

 In Java Swing, you can nudge components around within a GUI
 layout by adding Glue and Strut components.
 I would like to implement something similar using XSLT with my
 servlet's XML output, resulting in HTML table cells that
 incorporate a rudimentary layout manager...

 I would like to guarentee vertical table cell size, without
 knowing until XML generation time, how many text lines will be in
 the cell.

 I suppose that I would have to generate a tag/value combination
 that would specify the desired vertical line spacing, then I
 would have to count lines within the template match block that
 were copied through, and then take the difference (if one
 existed...) and send that value as a parameter to a subroutine
 that generated lines with just whitespace...

 Before I embark on this XSLT Odyssey, do the experienced XSLTers
 on this list think this is viable? Or are there hidden perils in
 this task that come to mind?

 -Jim Parsons, ArsDigita Corp.
 -jparsons@xxxxxxxxxxxxx

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Wendell Piez                            mailto:wapiez@xxxxxxxxxxxxxxxx
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