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Re: ISSUE-137 (including XML includes)

From: Jim Hendler <hendler@cs.rpi.edu>
Date: Mon, 15 Sep 2008 06:42:55 -0400
Cc: Ivan Herman <ivan@w3.org>, W3C OWL Working Group <public-owl-wg@w3.org>
Message-Id: <883726C0-9204-44FC-AADE-0733D4C61DAC@cs.rpi.edu>
To: Bijan Parsia <bparsia@cs.man.ac.uk>

Rather than inlining below - let me answer Bijan and Ivan
  My concern is that if I have an OWL 2 document in some format and I  
move it to an RDF/XML document, or vice versa, then we'll have  
interoperability problem with a "pure" Xinclude solution.  What I am  
suggesting is that we have some sort of directive (I am of mixed mind  
as to whether it would be suggested or required) that is used when  
Xinclude is used so there is something in the "OWL" (not in the  
serialization) that would help pick up the interoperability in this case
  for example, I could imagine that in the Ontology directory, at the  
level of owl:imports we could create owl:Xincludes or something like  
that (or perhaps to say that when an Xinclude is used an imports  
SHOULD (MUST?) also be used
  something like that
  -JH


On Sep 14, 2008, at 5:33 AM, Bijan Parsia wrote:

>
> On Sep 14, 2008, at 10:16 AM, Ivan Herman wrote:
> [snip]
>> - I agree with Alan, though, that the issue of other serializations  
>> is
>> of course real, too.
>
> Who denied that? I just deny that we need to solve the problem for  
> arbitrary other serializations. I would go farther and say that  
> *this group* doesn't have to solve it for Turtle (or rather, talking  
> about XInclude *does* "solve" it for Turtle as it wouldn't be at all  
> hard to Dave to add equivalent functionality in a sensible form).
>
> The point is that if we solve the problem for the syntaxes under our  
> care, we have done our job (qua wg). Qua community members, we still  
> need to go around to all the other syntaxes (and implementations)  
> and pester :)
>
>> Pushing this under carpet
>
> Excuse me, but I don't find this characterization fair at all. One  
> could as easily say, "pushing the ignoring of existing W3C standards  
> under the carpet...".
>
> I think Jim introduced a nicely balanced tone, let's stay there!
>
>> saying that there are no
>> other W3C standard serializations doesn't sound quite right for the
>> community. Other serializations are used in practice,
>
> And maintained by other people.
> [snip]
>
>> Having said that, the question that comes to my mind is whether a  
>> more
>> general inclusion mechanism is something this group has to solve or  
>> not.
>> Indeed (and that is where I might be wrong), I am not sure this is an
>> OWL specific issue. What makes it so? Isn't it some sort of a more
>> general RDF or, rather, RDF syntactic issue of declaratively  
>> including
>> one graph into an other? If this is not OWL specific, than I am not  
>> sure
>> an owl:include would be the right way of doing it. Ie, This may be
>> either an issue of the individual _RDF_ serializations, or maybe a  
>> more
>> general issue to be taken up if an when a new RDF Core Working group
>> comes around. Not this group's.
>
> I certainly agree (and have long argued...along with Jim,  
> IIRC,....that owl:import was similiarly "misleveled").
>
> But then Xinclude sanctioning is at least *possible* for this group  
> (and may be desirable). I.e., it's a standard, RDF/XML is a  
> standard, we're combining them in exactly the way they are intended  
> to be combined. I would worry about *any* bespoke solution for RDF  
> sending a bad message to the XML world.
>
> [snip]
>> [[[
>> XInclude [...] specifies a media-type specific (XML into XML)
>> transformation. It defines a specific processing model for merging
>> information sets.  XInclude processing occurs at a low level, often  
>> by a
>> generic XInclude processor which makes the resulting information set
>> available to higher level applications.
>> ]]] http://www.w3.org/TR/2006/REC-xinclude-20061115/#rel-xlink
>>
>> Ie, I do not believe it is possible to (mis-)use XInclude via some
>> tricks to use non-XML syntax. The way I read XInclude is that the
>> inclusion would, conceptually, take place *before* the resulting XML
>> Infoset is transformed into an RDF Graph.
>
> Which is, of course, one of it's advantages too. By "disappearing"  
> what the RDF level parser sees is just one big RDF/XML document and  
> treats it as such. (It's very much like a C include statement.)  
> Thus, your *model* don't contain extra stuff which either must be  
> ignored, or otherwise mucked with. This is why, for example, I would  
> much rather see a @prefix like mechanism in turtle than a triple:  
> Just as I don't want namespace declarations inside my RDF model (but  
> just URIs), I don't want include statements either. (Tastes and  
> circumstances vary, of course. But it's powerfully simplifying for  
> some form of inclusions to be simple transclusion.)
>
> Cheers,
> Bijan.
>

"If we knew what we were doing, it wouldn't be called research, would  
it?." - Albert Einstein

Prof James Hendler				http://www.cs.rpi.edu/~hendler
Tetherless World Constellation Chair
Computer Science Dept
Rensselaer Polytechnic Institute, Troy NY 12180
Received on Monday, 15 September 2008 10:43:44 GMT

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