Subject: Re: [xsl] XSL-FO versus PostScript|
From: "J.Pietschmann" <j3322ptm@xxxxxxxx>
Date: Wed, 26 Feb 2003 21:33:20 +0100
Could someone explain the advantages of XSL-FO over PostScript? As far as I can see, XSLT can be used to output both,
Certainly. However, the FO processor does quite an amount of computing, for example justifying spaces, adjusting lines if there are different font sizes used and perhaps hyphenation.
and PostScript looks like the more powerful language. Can't I exert more control over my documents if I go directly from XML to PostScript
Certainly. However, get an OS XSLFO processor and look what it does. If you want to use XSLT to directly generate PS, you are restricted to fairly easy and most of all to a stable layout, because the more complicated cases (like footnotes in changing page masters or aligning page numbers depending whether they are onn odd or even pages) get soon out of control.
The one argument I can see in favor of FO is that it presents a method of page description that is more intuitive than PostScript. But even that is kind of iffy. XSL-FO goes through a lot of hoops (like inheritance) to avoid programmatic flow control. And the result is fairly convoluted.
XSLFO was the first really systematic attempt on formalizing higher level layout. Of course it contains some cruft, mostly inherited from CSS (the most notable immediate predecessor).
If I'd put in charge of redesigning it without concerns for compatiblity, I'd change a few bits.