Re: Comments on SOAP 1.2 Attachment Feature

Chris' analysis deserves a more detailed reply than I can manage just now. 
  I agree that there's merit in much of it, but I'm not sure I agree with 
everything.

Anyway, the purpose of this note is specifically to signal my hesitancy to 
mandate support for any particular URI scheme such as CID.  I think we've 
done the right thing to leave it to the binding, because I think the 
natural URI scheme to use will depend strongly on the means used to move 
the attachments from sender to receiver.    So, how does this work in 
practice?  We don't specify node implementations, of course, but I would 
expect a typical implementation would be:

* Software preparing a message calls some API that says:  associate this 
byte stream as a new part with the message, and return to me a URI that 
can be used in the message to reference this part.   Under the covers, the 
software determines the packaging scheme to be used, and conjures up an 
appropriate URI. 

* Node uses those URIs when constructing references from the envelope, 
from other parts etc.

* Message is sent

* Receiving application encounters URIs, probably initially in the 
envelope, but maybe in other parts as processing proceeds.  Possible 
implementation is that SOAP software (with knowledge of the binding) 
offers a service that returns the byte stream for the part when presented 
with a URI.

So, I think what we have is both practical and appropriate.

------------------------------------------------------------------
Noah Mendelsohn                              Voice: 1-617-693-4036
IBM Corporation                                Fax: 1-617-693-8676
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Cambridge, MA 02142
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Marc Hadley <marc.hadley@sun.com>
Sent by: xml-dist-app-request@w3.org
09/04/2002 02:51 PM

 
        To:     xml-dist-app@w3.org
        cc:     (bcc: Noah Mendelsohn/Cambridge/IBM)
        Subject:        Comments on SOAP 1.2 Attachment Feature



Overall I think it looks OK though I share many of the concerns raised 
by Chris Ferris[1].

On the editorial front I would like to recommend redressing the balance 
between MIME and DIME by adding a reference to the SOAP with 
Attachments note[1] rather than just MIME itself. I would also 
recommend that the bibliography entries for WS-Attachments, WS-Security 
and SOAP with Attachments be moved to a new section; "Non-normative 
References" in line with approach taken for parts 1 and 2 of the spec.

On the technical front I wonder whether the spec should require/specify 
support for at least the CID[3] referencing scheme, rather than punting 
this completely to the packaging spec specification. This wouldn't 
preclude a packaging spec introducing additional referencing schemes 
but would provide at least a minimum of functionality common to all 
packaging specs.

Regards,
Marc.

[1] http://lists.w3.org/Archives/Public/xml-dist-app/2002Jul/0233.html
[2] http://www.w3.org/TR/SOAP-attachments
[3] http://www.ietf.org/rfc/rfc2111.txt

--
Marc Hadley <marc.hadley@sun.com>
XML Technology Center, Sun Microsystems.

Received on Wednesday, 4 September 2002 15:54:30 UTC