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Re: Syntax proposal for Issue 7728

From: Doug Davis <dug@us.ibm.com>
Date: Tue, 5 Jan 2010 12:30:58 -0500
To: Gilbert Pilz <gilbert.pilz@oracle.com>
Cc: ashok.malhotra@oracle.com, "public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org>
Message-ID: <OFBD2B265E.27070A70-ON852576A2.005FD87E-852576A2.00603C95@us.ibm.com>
We like rules  ;-)  The spec shouldn't allow for those attributes to 
appear in both places and it depends on how its used.  Within a 
mex:metadatasection - no attributes on the location.  Stand-alone, yes 
mex:location has the attributes.

thanks
-Doug
______________________________________________________
STSM |  Standards Architect  |  IBM Software Group
(919) 254-6905  |  IBM 444-6905  |  dug@us.ibm.com
The more I'm around some people, the more I like my dog.



Gilbert Pilz <gilbert.pilz@oracle.com> 
01/05/2010 12:11 PM

To
Doug Davis/Raleigh/IBM@IBMUS
cc
ashok.malhotra@oracle.com, "public-ws-resource-access@w3.org" 
<public-ws-resource-access@w3.org>
Subject
Re: Syntax proposal for Issue 7728






I really don't like the idea of adding @Dialect, @Identifier, and @View 
(people keep forgetting this, but it is important) to 
mex:MetadataReference/mex:Location because, as I said before, you then 
have to deal with (i.e. either specify the semantics for or rule out the 
existence of) situations in which some or all of these attributes appear 
at both the mex:MetadataSection "level" and the 
mex:MetadatReference/mex:Location level.

For example, what does it mean if you have:

<mex:Metadata>
  <mex:MetadataSection Dialect="wsdl">
    <mex:Location Dialect="xsd">

or

<mex:Metadata>
  <mex:MetadataSection Dialect="wsdl">
    <mex:MetadataSection Identifier="someURI">

W/regards to "showing all 3", I think we need to be careful to distinguish 
between what is allowed by WS-Addr extensibility and what we (WS-MEX) 
actually define semantics for. (1) is allowed by WS-Addr, but I don't see 
WS-MEX adding any value to this case.

- gp

On 12/29/2009 9:57 AM, Doug Davis wrote: 

I tend to agree.  Proposal #2 doesn't really add anything except a useless 
wrapper.  Proposal #1b might not work though since not all metadata under 
the wsa:Metadata element could be "WSDL" (or whatever URI is in the 
Dialect attribute).  Proposal #1a, if adopted, should be expanded to 
remove any ambiguity though.  Since there are three ways that metadata can 
be represented we should show all 3: 
1: Inlined 
<wsa:ReplyTo>
 <wsa:Address> http://ibm.com </wsa:Address>
 <wsa:Metadata> 
    <wsdl:definitions ...> ... </wsdl:definitions>
 </wsa:Metadata>
</wsa:ReplyTo> 

2: URL Reference 
<wsa:ReplyTo>
 <wsa:Address> http://ibm.com </wsa:Address>
 <wsa:Metadata>
   <mex:Location Dialect="wsdl"> some-URI </mex:Location>
 </wsa:Metadata>
</wsa:ReplyTo> 

3: EPR Reference 
<wsa:ReplyTo>
 <wsa:Address> http://ibm.com </wsa:Address>
 <wsa:Metadata>
   <mex:MetadataReference Dialect="wsdl"> 
      <wsa:Address> some-URI </wsa:Address> 
    </mex:MetadataReference>
 </wsa:Metadata>
</wsa:ReplyTo> 

However, we should also make it clear that there IS a case where the mex 
wrappers might appear - its the case where the metadata itself is the MEX 
document. 
So, if doing a Transfer.Get() to some mex:MetadataReference returns: 
  <mex:Metadata>
   <mex:MetadataSection Dialect="wsdl"> 
      <wsdl:definitions> ... </wsdl:definitions>
   </mex:MetadataSection>
 </mex:Metadata> 

Then when this metadata is inlined into an EPR it would appear like this: 
<wsa:ReplyTo>
 <wsa:Address> http://ibm.com </wsa:Address>
 <wsa:Metadata>
   <mex:Metadata>
     <mex:MetadataSection Dialect="wsdl"> 
        <wsdl:definitions> ... </wsdl:definitions>
     </mex:MetadataSection>
   </mex:Metadata> 
  </wsa:Metadata>
</wsa:ReplyTo> 

and the above EPR is semantically (from a metadata perspective) equivalent 
to: 
<wsa:ReplyTo>
 <wsa:Address> http://ibm.com </wsa:Address>
 <wsa:Metadata>
   <mex:MetadataReference Dialect="ws-mex"> 
      <wsa:Address> some-URI </wsa:Address> 
    </mex:MetadataReference>
 </wsa:Metadata>
</wsa:ReplyTo> 

Notice the Dialect is "ws-mex", not "wsdl". 

thanks
-Doug
______________________________________________________
STSM |  Standards Architect  |  IBM Software Group
(919) 254-6905  |  IBM 444-6905  |  dug@us.ibm.com
The more I'm around some people, the more I like my dog. 


ashok malhotra <ashok.malhotra@oracle.com> 
Sent by: public-ws-resource-access-request@w3.org 
12/29/2009 11:50 AM 

Please respond to
ashok.malhotra@oracle.com



To
"public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org> 
cc

Subject
Syntax proposal for Issue 7728








This proposal suggests a simplified syntax for attaching Metadata to MEX 
GetMetadata.  The proposal adds detail as a followup to the first point 
in the original statement of this issue.  The second point has been 
addressed via other issues.
We discussed this on our last telcon.  I'm following up with a specific 
proposal.

The proposal for issue 6463 which we are close to accepting has three 
levels of wrapping for the metadata, viz:

<wsa:ReplyTo>
 <wsa:Address> http://ibm.com </wsa:Address>
 <wsa:Metadata>
   <mex:Metadata>
     <mex:MetadataSection Dialect="wsdl">
       <mex:Location> http://ibm.com?wsdl </mex:Location>
     </mex:MetadataSection>
   </mex:Metadata>
 </wsa:Metadata>
</wsa:ReplyTo>

We think that this is too many layers of wrapping and suggest that one 
or two layers be removed.

Proposal 1

Remove both the <mex:Matadata> and the <nex:MetadataSection> wrappers. 
The above example would then look like:

<wsa:ReplyTo>
 <wsa:Address> http://ibm.com </wsa:Address>
 <wsa:Metadata>
     <mex:Location Dialect="wsdl"> http://ibm.com?wsdl </mex:Location>
 </wsa:Metadata>
</wsa:ReplyTo>

This syntax without any mex wrappers is already allowed by WS-Addressing.

Note that the Dialect attribute has been moved to the <mex:Location> 
element.  The Identifier attribute could be moved similarly. 
Alternatively, extension facilities could be used to add these 
attributes to the <was:Metadata> element.  The above example would then 
look like:

<wsa:ReplyTo>
 <wsa:Address> http://ibm.com </wsa:Address>
 <wsa:Metadata Dialect="wsdl">
     <mex:Location> http://ibm.com?wsdl </mex:Location>
 </wsa:Metadata>
</wsa:ReplyTo>

Proposal 2

The above proposal does simplify the syntax but requires the Dialect and 
Identifier attributes to be made available on other elements.  If we 
keep the <mex: MetadataSection> this is not necessary although the 
proposal gets a bit more verbose:

<wsa:ReplyTo>
 <wsa:Address> http://ibm.com </wsa:Address>
 <wsa:Metadata>
    <mex:MetadataSection Dialect="wsdl">
       <mex:Location> http://ibm.com?wsdl </mex:Location>
    </mex:MetadataSection
 </wsa:Metadata>
</wsa:ReplyTo>

-- 
All the best, Ashok
Received on Tuesday, 5 January 2010 17:32:00 GMT

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