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Re: IDREF vs HREF for graph edges in SOAP encoding

From: Edwin Ortega <ortegae@wns.net>
Date: Wed, 16 Jan 2002 13:27:04 -0800
Message-ID: <011501c19ed4$926914a0$32a2583f@val6000>
To: "Jean-Jacques Moreau" <moreau@crf.canon.fr>, "Christopher Ferris" <chris.ferris@sun.com>
Cc: "Martin Gudgin" <marting@develop.com>, "Marc Hadley" <marc.hadley@sun.com>, "XML dist app" <xml-dist-app@w3c.org>

----- Original Message -----
From: "Jean-Jacques Moreau" <moreau@crf.canon.fr>
To: "Christopher Ferris" <chris.ferris@sun.com>
Cc: "Martin Gudgin" <marting@develop.com>; "Marc Hadley"
<marc.hadley@sun.com>; "XML dist app" <xml-dist-app@w3c.org>
Sent: Wednesday, January 16, 2002 7:09 AM
Subject: Re: IDREF vs HREF for graph edges in SOAP encoding


> .. only insofar as basic types are concerned, as far as I understand.
>
> Jean-Jacques.
>
>
> Christopher Ferris wrote:
>
> > Only if one wanted to leverage the internal subset,
> > other than that, you could treat them in the same
> > manner as href and id. It would certainly be much
> > more convenient for implementations that did choose
> > to leverage DTD processing. Given that we're talking
> > about encoding, which leverages XML Schema types, it
> > is pretty clear to me that we're also imposing schema
> > processing anyway, no?
> >
> > Cheers,
> >
> > Chris
> >
> > Martin Gudgin wrote:
> >
> > > I may be missing some context for this discussion but...
> > >
> > > Wouldn't using IDREFs *REQUIRE* DTD or Schema processing of SOAP
messages?
> > >
> > > Gudge
> > >
> > > ----- Original Message -----
> > > From: "Marc Hadley" <marc.hadley@sun.com>
> > > To: "XML dist app" <xml-dist-app@w3c.org>
> > > Sent: Thursday, January 10, 2002 2:28 PM
> > > Subject: IDREF vs HREF for graph edges in SOAP encoding
> > >
> > >
> > >
> > >>All,
> > >>
> > >>On last nights telcon, Jacek and I took an action to start discussion
on
> > >>the list about the merits of using IDREFs instead of generic HREFs for
> > >>representing graph edges in the SOAP encoding.
> > >>
> > >>Attached is a table and commentary in HTML format listing a number of
> > >>problems and issues concerned with the use of links as graph edges.
> > >>Possible solutions are also shown for the two cases: graph edges as
> > >>IDREFs or generic hrefs.
> > >>
> > >>Note that switching to IDREFs for graph edges does not preclude use of
> > >>arbitrary links in encoded data. The switch only affects the kind of
> > >>links used for encoded graph edges.
> > >>
> > >>Comments, flames, etc ?
> > >>
> > >>Marc and Jacek.
> > >>
> > >>--
> > >>Marc Hadley <marc.hadley@sun.com>
> > >>XML Technology Centre, Sun Microsystems.
> > >>
> > >>Jacek Kopecky <jacek@systinet.com>
> > >>Senior Architect, Systinet (formerly Idoox)
> > >>
> > >>
> > >>
> > >>
> > >>
> > >
> > >
> >
> --------------------------------------------------------------------------
--
> > > ----
> > >
> > >
> > >
> > >>Problems of hrefs vs. IDREFsProblems of hrefs vs. IDREFs
> > >>     Problem Description Solution
> > >>
> > >>      IDREF HREF
> > >>      1 Type of Node.  Currently the type of a node is specified using
> > >>
> > > xsi:type either explicitly or via a schema. This may not be the case
for the
> > > targets of external links. No change required. Remove the requirement
that
> > > all values are typed, possibly adding other means of deriving the
xsi:type,
> > > e.g. from the resources MIME type.
> > >
> > >>      2 Dereferencing When, or if, to attempt to dereference links.
All
> > >>
> > > graph edges are internal to the envelope. Therefore deserialisation
> > > MUST/SHOULD dereference all links, any failure MUST generate a fault.
Some
> > > graph edges may be external to the envelope. Deserialisation layer
> > > MUST/SHOULD dereference internal links, MAY dereference external links
and
> > > MAY/SHOULD/MUST fault when an link is not dereferenceable. Should the
> > > faulting semantics be different for internal and external graph edges
?
> > >
> > >>      3 Representation of external data in programming languages
Internal
> > >>
> > > data with xsi:type is mapped naturally into programming language
types, how
> > > about external data? Not applicable. The implementation represents
binary
> > > data in byte arrays or streams, XML data is represented as usual.
> > >
> > >>      4 Serialising internal vs external links. During serialisation,
the
> > >>
> > > SOAP processor has to decide what to include as internal content and
what is
> > > left as an external resource. Not applicable. Either the SOAP
processor has
> > > to be told or has to have some ad-hoc rules.
> > >
> > >>      5 Distinction between internal and external links The SOAP
processor
> > >>
> > > has to be able to work out which links are internal and which are
external.
> > > Not applicable. SOAP processor has to implement logic based on the URI
> > > schemes supported.
> > >
> > >>      6 Full implementation of external link support in core. If
external
> > >>
> > > links are permitted in the encoding then every generic SOAP processor
must
> > > be able to handle them. Not applicable, any external links are just
node
> > > values. External link support required.
> > >
> > >>      7 Support for SOAP with attachments Currently the SOAP with
> > >>
> > > attachments specification uses the href attribute to refer to
attachments
> > > from within the envelope. A new higher level construct is required,
e.g. :
> > >
> > >>      <parameter xsi:type="soapatt:att">
> > >>          cid:....
> > >>      </parameter>
> > >>
> > >>      i.e. SOAP with attachments support is layered on top of the core
> > >>
> > > encoding.
> > >
> > >>     No change required
> > >>
> > >>Remarks
> > >>Only the problem no. 2 requires some added language in case we should
> > >>
> > > choose IDREFs and that language is IMHO crisper and less vague (prone
to
> > > misinterpretation) than the current text for the href case.
> > >
> > >>So actually going with hrefs requires us to specify a lot (solving
> > >>
> > > problems 1, 2, 3, 4, 5) and results in more complicated
implementation,
> > > while going with IDREFs requires us to change/specify a relatively
little
> > > (2, 7) and the implementation is simplified. By the way, we consider
the
> > > change to attachments a cleanup change.
> > >
> > >>
> > >
>
>
Received on Wednesday, 16 January 2002 12:41:24 GMT

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