Proposal for issue 390

Issue 390 [0] is part of WSA's review of the AF document.

The first part of the issue is a general request to explain why and
when using the attachments (rather than links to resources):

  " We recommend the XML Protocol Working Group
    to document the motivations for using the SOAP Attachment Feature,
    for example with a set of usage scenarios."

AF doc's introduction [1] partly gives an answer, from an encoding
point of view. But at the application level, it seems to be out of scope
of this document to provide guidelines about using attachments or not.
Usage scenarios would at least depend on the bindings used by the
application.

The second part of the issue asks clarifications about how resources
on the web (referenced by a URI) are added as a part (how a change of
reference is handled):
    
    " For example, a reference in a SOAP element might be 
    <http://example.com/Sound.wav>.  My SOAP application now uses 
    some SOAP attachment feature, perhaps MIME. The representation is 
    now identified by <cid:someidentifierforSoundwav>. "

If a SOAP node is able to do this change it means that it may have good
reason to do so (e.g. next node will be unable to resolve the URI), and it
means that this node is aware of the processing capabilities of the next
node, in that case it acts as the terminal node and is able to change the
nature of the SOAP message. Also, although the bit-level representation of
http://example.com/Sound.wav and <cid:someidentifierforSoundwav> may not
be the same over time. Ie: those two references are NOT the same and have
a different semantic.
Based on that, the request would not be the same, which is out of scope of
this document, as it would be defined by the application semantics of this
transformation node.
A paragraph about forwarding secondary parts may be added to paragraph 6
(implementation) [2] along those lines:
"A node should be extremely careful if it decides to retrieve a
URI-referenced document and embed it in the secondary part bag, as the
semantic of this attachment may no longer be the same."


Any comments?


[0] http://www.w3.org/2000/xp/Group/xmlp-lc-issues#x390
[1] http://www.w3.org/TR/2002/WD-soap12-af-20020814/#intro
[2] http://www.w3.org/TR/2002/WD-soap12-af-20020814/#implementation


-- 
Carine Bournez -+- W3C / INRIA Sophia-Antipolis

Received on Sunday, 27 October 2002 11:19:56 UTC