- From: <noah_mendelsohn@us.ibm.com>
- Date: Fri, 13 Sep 2002 10:06:43 -0400
- To: "Jean-Jacques Moreau" <moreau@crf.canon.fr>
- Cc: carine@w3.org, chrisfer@us.ibm.com, dorchard@bea.com, henrikn@microsoft.com, John_Barton@hpl.hp.com, ruellan@crf.canon.fr, xml-dist-app@w3.org, ylafon@w3.org
Jean-Jacques Moreau writes: >> My assumption so far was that the SOAP processor >> and the "packaging module" would be one and the >> same thing, i.e. an extended SOAP processor; >> but I agree they could indeed be kept >> separate. Let's keep in mind that SOAP does not discuss implementations. It presents wire formats and describes their interpretation, in this case as a primary envelope with linked non-envelope parts. How code is structured, combined, etc. is beyond the scope of our specifications. The term node is therefore a catchall for that block box that you build that receives or sends SOAP messages. How you structure it is up to you, and may be different from the way I do it. ------------------------------------------------------------------ Noah Mendelsohn Voice: 1-617-693-4036 IBM Corporation Fax: 1-617-693-8676 One Rogers Street Cambridge, MA 02142 ------------------------------------------------------------------ "Jean-Jacques Moreau" <moreau@crf.canon.fr> Sent by: xml-dist-app-request@w3.org 09/13/02 06:54 AM To: "John J. Barton" <John_Barton@hpl.hp.com> cc: David Orchard <dorchard@bea.com>, "'Christopher B Ferris'" <chrisfer@us.ibm.com>, "'Henrik Frystyk Nielsen'" <henrikn@microsoft.com>, "'Carine Bournez'" <carine@w3.org>, "'Herve Ruellan'" <ruellan@crf.canon.fr>, xml-dist-app@w3.org, "'Yves Lafon'" <ylafon@w3.org>, (bcc: Noah Mendelsohn/Cambridge/IBM) Subject: Re: New AFTF draft. Interesting perspective. I think what you call a SOAP module is what we call a SOAP processor; SOAP 1.2 defines a module as the SOAP header block implementing a given SOAP feature (e.g. authentication). My assumption so far was that the SOAP processor and the "packaging module" would be one and the same thing, i.e. an extended SOAP processor; but I agree they could indeed be kept separate. Jean-Jacques. John J. Barton wrote: > I'm sorry that I was not clear. Let me try again. > > If we describe the package, then we have no problems. > We have some bytes in some formats and we simply > give the rules for those formats. > > But what is being attempted in AFTF is to describe the > relation between a SOAP message and attachments > without describing the package. Naturally this description > starts with the SOAP message and proceeds to the URI > that names an attachment. Here is where the trouble > begins. A URI names a Resource. We know > that, in this particular example, resolving this resource > will give a copy of the bits in the attachment. After all > we made the example up. But, in general, the > SOAP module processing the message does NOT know > that any particular URI will give a copy of the bits in an > attachment. That flexibility is why we used a URI. > So the SOAP module (and hence the SOAP message) > knows the attachment only as a resource. It has an > interface "GET URI" and just in this case the implementation > is an attachment. > > That is what I meant by "From the perspective of the SOAP > module the attachments are resources." It only has URIs. > > In processing the SOAP message we eventually have to > resolve GET URI into some bits. I called that place in the > process the packaging module. The resolution of the URI > sucks up the bits of the attachment and passes them to > the SOAP module: then we have a representation of the > resource. > > That is what I meant by "From the perspective of the packaging > module the attachments are representations." > > In both cases the key phrase is "from the perspective". Both > "resource" and "representation" are about roles or views of > bits. Resources are abstractions of bits; representations are > reification of those abstractions. Neither are the bits. > > I don't think that equating attachments to representations > will be helpful in the long run for exactly the reasons that > we cannot equate bits of a database or file system to representations > in the Web today. Attachments, like database entries, are just > bits to be interpreted by a URI scheme processor to produce a > representation. A few primitive scheme processors will simply > copy bits: that's what "file:" does and often what "http:" does. > There are lots of alternatives in the web today and soon they > will be applied to SOAP messages as well. > > If I attach a perl program is it a representation? If I attach > a database? an exe? How about a complete file system? > If it has to be interpreted to become a representation then > how can it be a representation? > > John. > > At 08:14 PM 9/11/2002 -0700, David Orchard wrote: > >> I think I disagree that attachments are resources from the soap module >> perspective. Regardless of the packaging or boxcarring mechanism, >> they are >> representations in flight. URI usage does not mean that attachments are >> resources. >> >> Cheers, >> Dave >> >> > -----Original Message----- >> > From: John J. Barton [mailto:John_Barton@hpl.hp.com] >> > Sent: Wednesday, September 11, 2002 8:43 AM >> > To: David Orchard; 'Jean-Jacques Moreau'; 'Christopher B Ferris' >> > Cc: 'Henrik Frystyk Nielsen'; 'Carine Bournez'; 'Herve Ruellan'; >> > xml-dist-app@w3.org; 'Yves Lafon' >> > Subject: RE: New AFTF draft. >> > >> > >> > From the perspective of the SOAP module the attachments are >> > resources. That is why we use URIs to name them. >> > >> > From the perspective of the packaging module the attachments >> > are representations. It deals with bytes. >> > >> > The confusing concept from the Web point of view is "Compound >> > SOAP structure". This programming construct cannot be >> > precisely defined: it may contain pointers that are not bound. A >> > compound SOAP structure is a logically a "view" rather than a >> > physical region of memory or a packet of data. The construct >> > that can be defined is the message package. That is why writing >> > the spec for the package is easier that defining how the package >> > looks from the SOAP layer. >> > >> > John. >> > >> > At 06:44 AM 9/11/2002 -0700, David Orchard wrote: >> > >> > >Seems to me it should be a representation rather than a >> > resource. Even >> > >though the representation might be identified by a URI (and >> > so be confused >> > >with a Resource). The web architecture is pretty clear that >> > resources are >> > >hidden by servers. >> > > >> > >Cheers, >> > >Dave >> > > >> > > > -----Original Message----- >> > > > From: xml-dist-app-request@w3.org >> > > > [mailto:xml-dist-app-request@w3.org]On >> > > > Behalf Of Jean-Jacques Moreau >> > > > Sent: Wednesday, September 11, 2002 3:04 AM >> > > > To: Christopher B Ferris >> > > > Cc: Henrik Frystyk Nielsen; Carine Bournez; Herve Ruellan; >> > > > xml-dist-app@w3.org; Yves Lafon >> > > > Subject: Re: New AFTF draft. >> > > > >> > > > >> > > > >> > > > They're not resources, but representations of resources? >> > > > Personally, I think part reads better than resource in >> > this context. >> > > > >> > > > Jean-Jacques. >> > > > >> > > > Christopher B Ferris wrote: >> > > > > Well, there's 'resource' which fits in nicely with the Web >> > > > architecture. >> > > > > >> > > > > e.g. >> > > > > "Compound SOAP structure >> > > > > A compound SOAP structure consists of a primary >> > > > SOAP message part >> > > > > and zero or more related resources." >> > > > > >> > > > > I would even go as far as to add: "identified by a URI". >> > > > >> > >> > ______________________________________________________ >> > John J. Barton email: John_Barton@hpl.hp.com >> > http://www.hpl.hp.com/personal/John_Barton/index.htm >> > MS 1U-17 Hewlett-Packard Labs >> > 1501 Page Mill Road phone: (650)-236-2888 >> > Palo Alto CA 94304-1126 FAX: (650)-857-5100 >> > >> > > > > ______________________________________________________ > John J. Barton email: John_Barton@hpl.hp.com > http://www.hpl.hp.com/personal/John_Barton/index.htm > MS 1U-17 Hewlett-Packard Labs > 1501 Page Mill Road phone: (650)-236-2888 > Palo Alto CA 94304-1126 FAX: (650)-857-5100 >
Received on Friday, 13 September 2002 10:11:48 UTC