Primer LCWD [was RE: RE: Policy Retrieval Algorithms]

I never had the time to follow up on Paul's 
suggestion (from a year ago) [4] regarding 
WS-PolicyAttachment, but perhaps a comment is in 
order for the Primer WG Note (now in LCWD) to at 
least caution implementers that @URI may or may 
not be resolvable, and if it is resolvable that 
@URI may not be a direct link to a representation 
whose content type is application/wspolicy+xml.

[2] 
http://www.w3.org/TR/2007/WD-ws-policy-primer-20070928/#Referencing_Policy_Expressions
[3] http://www.w3.org/TR/2007/REC-ws-policy-20070904/#Policy_References
[4] http://lists.w3.org/Archives/Public/public-ws-policy/2006Oct/0134.html

Suggest adding the following text to the end of 
section 2.10 [2] (pertaining to example 2-20):

<proposal>

Note that the value of the URI attribute 
information item (defined in [3]) may or may not 
be directly resolvable to retrieve the policy 
expression.  This attribute (@URI) may be an 
identifier, and mechanisms for retrieving the 
policy expression identified by @URI may not be 
obvious.  Such mechanisms are out-of-scope for 
[Web Services Policy Framework] and [Web Services Policy Attachment].

The following example shows a policy expression 
identified using a UDDI tModelKey, which may 
refer to a tModel that references the policy 
expression as described in section 6.3 of [Web Services Policy Attachment].

Example 2-20a. PolicyReference to Common Policy Expression via UDDI

<PolicyReference URI="uddi:3bed4710-1f46-11dc-899e-391cf3b1899c"/>


</proposal>

Below snippet may help editors add this example 
to the document.  If you accept this proposed 
change, you may want to re-number the examples.

<div class="exampleOuter">
<p style="text-align: left" class="exampleHead"><i><span>Example
2-20a.</span> PolicyReference to Common Policy Expression</i></p>


<div class="exampleInner">
<pre>
&lt;PolicyReference URI="uddi:3bed4710-1f46-11dc-899e-391cf3b1899c"/&gt;
</pre></div>
</div>


What I am not clear about is constraints on the 
value of wsp:Policy/@wsp:Name, like in Example 
2-19.  For my UDDI example above, would the @Name 
need to be the UDDI tModelKey?


<Policy Name=”uddi:3bed4710-1f46-11dc-899e-391cf3b1899c”>
   <mtom:OptimizedMimeSerialization wsp:Optional="true"/>
   <wsam:Addressing>…</wsam:Addressing>
</Policy>


(There are probably some related words that 
should go into section 3.6, but I'll send a separate email on that.)

Paul

At 01:17 PM 2006-10-18, Paul Cotton wrote:
>I agree with Dan that nothing more is actually 
>in the Policy spec to specify how the resources can be retrieved.
>
>Paul Denning: If you think something specific 
>needs to be added please open a new WS-Policy 
>issue [1] and give us a clear rationale for the missing functionality.
>
>/paulc
>
>[1] http://www.w3.org/2002/ws/policy/#issues
>
>
>Paul Cotton, Microsoft Canada
>17 Eleanor Drive, Ottawa, Ontario K2E 6A3
>Tel: (613) 225-5445 Fax: (425) 936-7329
>mailto:Paul.Cotton@microsoft.com
>
>
>
>
>From: public-ws-policy-request@w3.org 
>[mailto:public-ws-policy-request@w3.org] On Behalf Of Daniel Roth
>Sent: October 11, 2006 11:26 AM
>To: Paul Denning; public-ws-policy@w3.org
>Subject: RE: Policy Retrieval Algorithms
>
>Hi Paul,
>
> > there is no requirement that the IRI be resolvable
>
>I would also note that the IRI CAN be 
>resolvable.  Using resolvable IRIs seems like a 
>natural and interoperable way of dealing with external references.
>
> > defining a way to identify a retrieval mechanism could/should be in scope.
>
>This seems unnecessary since IRI’s already 
>define a way to specify how to resolve 
>them.  Supporting more creative resolution 
>mechanisms seems like a Policy vNext feature.
>
>Daniel Roth
>
>
>From: public-ws-policy-request@w3.org 
>[mailto:public-ws-policy-request@w3.org] On Behalf Of Paul Denning
>Sent: Friday, October 06, 2006 12:47 PM
>To: public-ws-policy@w3.org
>Subject: Policy Retrieval Algorithms
>
>[1] http://tinyurl.com/ot5x5#Policy_References
>
>Section 4.3.4 states
>
>"...there is no requirement that the IRI be 
>resolvable; retrieval mechanisms are beyond the scope of this specification."
>
>I would agree that defining various retrieval 
>mechanisms would be out of scope, but defining a 
>way to identify a retrieval mechanism could/should be in scope.
>
>Perhaps adding
>
><proposal>
>
>wsp:PolicyReference/@RetrievalAlgorithm
>
>   This optional URI attribute specifies the 
> Retrieval Algorithm being used to resolve an 
> external policy expression identified by ./@URI.
>
></proposal>
>
>
>Note that this is modeled after the 
>DigestAlgorithm.  You would not provide @Digest 
>without specifying the @DigestAlgorithm used to calculate it.
>
>@Digest is opaque and you cannot determine the 
>digest algorithm by looking at its value.
>
>Likewise, we should treat @URI as opaque and 
>provide an identifier for the algorithm that can 
>be used to resolve the external policy expression.
>
>Paul

Received on Friday, 19 October 2007 17:14:07 UTC