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Re: issue 6432 - yet another proposal

From: ashok malhotra <ashok.malhotra@oracle.com>
Date: Wed, 08 Apr 2009 13:39:11 -0700
Message-ID: <49DD0B6F.8030902@oracle.com>
To: Christopher B Ferris <chrisfer@us.ibm.com>
CC: "public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org>
Thanks, Chris!  That's an excellent analysis.
All the best, Ashok


Christopher B Ferris wrote:
> Jeff is correct. Opacity is not a quality of an URI. It is a 
> principle: you should not infer anything from the
> structure (or the content) of the path component of the URI. Note the 
> use of the word "should" - I'll come back to that
> later.
>
> For instance, just because an URI ends in .pdf does NOT mean that the 
> client/agent that uses that URI in a GET
> should expect to receive an application/pdf media type in the response 
> entity body.
>
> So, repeat after me, opacity is not a quality, it is a principle. One 
> URI is neither more, nor less "opaque" than another.
> Period.
>
> Now, what Asir may be alluding to is that the MC Anon URI is 
> constructed from a URI template:
>
>         
> http://docs.oasis-open.org/ws-rx/wsmc/200702/anonymous?id={unique-String}
>
> Here's where the opacity principle can be ignored: when the URI 
> authority provides explicit information as to how to
> interpret the structure of the URI, as the WS-Make Connection spec [1] 
> does. One can do a character for character
> match of the string
>
>         http://docs.oasis-open.org/ws-rx/wsmc/200702/anonymous?id=
>
> If it matches the first 58 characters of another URI, then that 
> (other) URI is a MCanon URI.
>
> I refer you to the TAG finding that specifies that such practice is 
> just fine thank-you very much [2] (3nd bullet in conclusions section):
>
> "* Assignment authorities may publish specifications detailing the 
> structure and semantics of the URIs they assign. Other users of those 
> URIs may use such specifications to infer information about resources 
> identified by URI assigned by that authority."
>
> [1] 
> http://docs.oasis-open.org/ws-rx/wsmc/200702/wsmc-1.1-spec-os.html#_Toc162743905 
>
> [2] http://www.w3.org/2001/tag/doc/metaDataInURI-31-20061204.html
>
> Cheers,
>
> Christopher Ferris
> IBM Distinguished Engineer, CTO Industry Standards
> IBM Software Group, Standards Strategy
> email: chrisfer@us.ibm.com
> blog: http://www.ibm.com/developerworks/blogs/page/chrisferris
> phone: +1 508 234 2986
>
>
>
>
> From: 	Jeff Mischkinsky <jeff.mischkinsky@oracle.com>
> To: 	Yves Lafon <ylafon@w3.org>
> Cc: 	Gilbert Pilz <gilbert.pilz@oracle.com>, Asir Vedamuthu 
> <asirveda@microsoft.com>, Doug Davis/Raleigh/IBM@IBMUS, 
> "public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org>
> Date: 	04/08/2009 03:16 PM
> Subject: 	Re: issue 6432 - yet another proposal
> Sent by: 	public-ws-resource-access-request@w3.org
>
>
> ------------------------------------------------------------------------
>
>
>
> hi,
>   My understanding of the use of "opaque" wrt to URI's is that you  
> are not supposed to infer anything from the structure of the URI, not  
> that specific uri's don't have specific "meanings"/semantics as  
> defined in specs.
>   Otherwise it is totally meaningless to define a uri and give it  
> semantics.
> So this argument and asir's response don't make sense to me. You can  
> certainly tell that the 2 uri's in question are different and you can  
> certainly know what the semantics of using them are. So i don't see a  
> problem.
>    -jeff
> On Apr 08, 2009, at 2:34 AM, Yves Lafon wrote:
>
> > On Tue, 7 Apr 2009, Gilbert Pilz wrote:
> >
> >> WS-Addressing 1.0 - Core defines two "special" URIs;
> >> "http://www.w3.org/2005/08/addressing/anonymous" and
> >> "http://www.w3.org/2005/08/addressing/none". Messages targeted to  
> >> either
> >> of these URIs are processed differently from messages targeted to
> >> "normal" URIs such as "http://webserivce.bea.com/. . .".
> >
> > Well, they are different, but unless you know WS-Addressing, or  
> > unless you resolve http://www.w3.org/2005/08/addressing/anonymous  
> > and find out the relationship between this URI and the WS-Addressing  
> > spec.
> > If you resolve http://webservice.bea.com/.. 
> <http://webservice.bea.com>. you will probably have  
> > information about the endpoint, or you may know it in advance from  
> > another document. So both URIs are opaque, unless you know their  
> > semantic.
> >
> >
> > --
> > Baroula que barouleras, au tiéu toujou t'entourneras.
> >
> >        ~~Yves
> >
> >
>
> --
> Jeff Mischkinsky                                                       
>                                         jeff.mischkinsky@oracle.com
> Director, Oracle Fusion Middleware                                     
>                                 +1(650)506-1975
>                 and Web Services Standards                             
>                                  500 Oracle Parkway, M/S 2OP9
> Oracle                                                                 
>                                                                       
>  Redwood Shores, CA 94065
>
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Received on Wednesday, 8 April 2009 20:41:33 UTC

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