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Re: 6.2 in xsl-fo 1.1

From: Tony Graham <Tony.Graham@MenteithConsulting.com>
Date: Thu, 09 Dec 2010 10:10:18 +0000
To: www-xsl-fo@w3.org
Message-ID: <87r5drjlyt.fsf@takai.menteithconsulting.com>
On Thu, Dec 09 2010 07:49:21 +0000, dave.pawson@gmail.com wrote:
> On 8 December 2010 21:07, Liam R E Quin <liam@w3.org> wrote:
>
>> The notation used is described in 6.2, "Formatting Object Content",
>> http://www.w3.org/TR/2006/REC-xsl11-20061205/#d0e6532
>
> there is no explanation of PCDATA in 6.2 Liam? Only what substitutions
> may be made.

Section 6.2 begins "The content of a formatting object is described
using XML content-model syntax."  '#PCDATA' is part of XML content model
syntax.

>> Although DTDs are less commonly used these days, they're still very
>> much part of XML of course. Do you think that it'd be clearer if we
>> used some other notation for 2.0?
>
> I'm wondering if that is clear, or makes an assumption about
> DTD understanding?

XML content models are part of XML 1.0.

> The content models used do stand for use in relax NG,
> just that they aren't complete? See my bugzilla entreis.

The second sentence of section 6,2 is "In some cases additional
constraints, not expressible in XML content models, are given in prose."

Section 6 is about Formatting Objects, which is part of what you get
after you "objectify" the XML [1]:

   The first step in formatting is to "objectify" the element and
   attribute tree obtained via an XSLT transformation. Objectifying the
   tree basically consists of turning the elements in the tree into
   formatting object nodes and the attributes into property
   specifications. The result of this step is the formatting object
   tree.

The descriptions of the contents are presumably called "contents", not
"content models", because you're not talking about XML at that point,
same as the property descriptions define what's allowed after you've
evaluated property attribute values as expressions, not what's allowed
in the XML attributes.

XSLT 2.0 works on the "XPath 2.0 and XQuery 1.0 data model (XDM)" [2],
and W3C XML Schema works on the XML infoset, so XSL is not alone in
defining things in post-XML-document terms.

Even viewed as XML, there are aspects, such as fo:marker, that confound
DTD content models, and aspects, such as what may be a descendant of
what, that confound just about every other schema mechanism.

> the use of %xxx; notation is perhaps becoming an oddity
> as DTDs fall out of use.  Perhaps xInclude notation,
> providing the xIclude expansion in the XML version of
> the rec, yet not expanding them in the (to be printed) rec?
> That way they could be verified as being 'as intended'.

There is a requirement for a schema for XSL FO 2.0 [3].  However that is
defined will probably go hand-in-hand with however FO contents are
described in an XSL FO 2.0 spec.

I am all for being able to use the XSL spec as data: xmlroff includes
thousands of lines of C code that was generated from the spec using XSLT
[4].

Note also that the current XSL FO 2.0 WD (mostly) continues the XSL 1.1
conventions for IDs for sections describing FOs [5] and properties [6]
because we want to continue to enable current processing tools.

Regards,


Tony Graham                         Tony.Graham@MenteithConsulting.com
Director                                  W3C XSL FO SG Invited Expert
Menteith Consulting Ltd                               XML Guild member
XML, XSL and XSLT consulting, programming and training
Registered Office: 13 Kelly's Bay Beach, Skerries, Co. Dublin, Ireland
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[1] http://www.w3.org/TR/xsl11/#d0e209
[2] http://www.w3.org/TR/xslt20/#data-model
[3] http://www.w3.org/TR/xslfo20-req/#N67198
[4] http://www.xmlprague.cz/2009/posters.html#xslt_for_c_generation
[5] http://www.w3.org/TR/xslfo20/#fo_shape
[6] http://www.w3.org/TR/xslfo20/#text-align-before-break
Received on Thursday, 9 December 2010 10:10:49 GMT

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