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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 13:25:33 -0800
Message-ID: <00bd01c19ed4$58dcb840$32a2583f@val6000>
To: "Martin Gudgin" <marting@develop.com>, "Marc Hadley" <marc.hadley@sun.com>, "XML dist app" <xml-dist-app@w3c.org>

----- Original Message -----
From: "Martin Gudgin" <marting@develop.com>
To: "Marc Hadley" <marc.hadley@sun.com>; "XML dist app"
<xml-dist-app@w3c.org>
Sent: Wednesday, January 16, 2002 5:55 AM
Subject: Re: IDREF vs HREF for graph edges in SOAP encoding


> 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 12:41:15 GMT

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