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Re: issue 168 proposal: xsi:type of external references in Encoding

From: Noah Mendelsohn <noah_mendelsohn@us.ibm.com>
Date: Mon, 10 Dec 2001 13:06:24 -0500
To: "Jacek Kopecky <jacek" <jacek@systinet.com>
Cc: "xml-dist-app" <xml-dist-app@w3.org>
Message-ID: <OF72546EF9.1CCACA6E-ON85256B1E.006325B5@pok.ibm.com>

As I've suggested before, I think there are issues relating to external
references that go beyond the encodings, and I think our approach has to be
consistent across the cases.  If I send you a document that uses encoding
and has an href to some other URL, what are my obligations in following
that link?  It has very bad performance and security implications if you
even imply that a conforming implementation MUST try to open a random URL
that happens to show up in the href of a document.

This also relates to our handling of SOAP+Attachments and DIME, which I
think we've delayed for now.

So, we need to indicate in the encodings, what is the result if there is an
href you choose not to follow or can't follow?  Is it that a fault should
be generated?  Is it the same fault as if an href in the form of a fragment
referencing the envelope itself fails?  Thanks.

Noah Mendelsohn                                    Voice: 1-617-693-4036
Lotus Development Corp.                            Fax: 1-617-693-8676
One Rogers Street
Cambridge, MA 02142

                      Jacek Kopecky                                                                                                   
                      <jacek@systinet.         To:      <xml-dist-app@w3.org>                                                         
                      com>                     cc:                                                                                    
                      Sent by:                 Subject: issue 168 proposal: xsi:type of external references in Encoding               
                      12/09/01 02:05                                                                                                  

 Hi all. 8-)
 This is a proposal for resolving issue 168 [1].
 The issue wants to know the XML Schema Instance type of the data
that is referenced by the href attribute and that is external to
the referencing document.

 The proposal:
 The type of referenced data depends on whether the referenced
document is an XML document or not. The possible means of
determining whether a particular document is XML or not include
using MIME types, file extensions or file introspection.
 In case the document is XML, the referenced data is either the
root element or the element identified by its ID (in case the
referencing URL contains the #<id> part), the type of this data
is determined the same way as if the reference was internal.
 In case the document is not XML, the type of the referenced data
is enc:binary, a simple type with the value space of the set of
finite-length sequences of binary octets and the same lexical
space. [guess I'll need somebody's help with this definition]

 A different proposal could try to introduce some means of
otherwise typing the data (for example an attribute
enc:hrefType). To me this seems too complicated.
 Yet another proposal could disallow external references
altogether. This would IMO meet big push back from the proponents
of the current practice of attaching data.

 Anyway, here it is, read for being discussed. 8-)

                   Jacek Kopecky

                   Senior Architect, Systinet (formerly Idoox)

[1] http://www.w3.org/2000/xp/Group/xmlp-issues.html#x168
Received on Monday, 10 December 2001 14:51:44 UTC

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