Re: Possible v.next issue : simple policy language extension

Sergey, is this a reference to a single assertion?

Ashok

Sergey Beryozkin wrote:

> Hi
>  
> I'd like to suggest a possible simple policy language extension for 
> the *next version* of WS-Policy.
> Please consider this request as a low-priority issue, I don't want to 
> distract the working group from more important/urgent things it needs 
> to finalize. If the groups find this suggestion of any interest then 
> the only thing I'd expect is a list of v.next issues be updated.
>  
> So here it goes. If a policy author wants to express the simplies 
> capability/requirement, the most compact way to do it is to use a 
> compact form, for ex :
>  
> <Policy>
>  <wsm:MTOM/>
> </Policy>
>  
> I personally have no problems with it at all, it's compact enough for 
> me and a Policy operaror provides for more than just serving as a 
> simple container about the primitive (<wsm:MTOM/>) policy assertion.
>  
> Now, I've had a look recently at APP Feature Discovery Draft [1].
> According to the draft one can express a capability like this :
>  
> <f:feature xmlns:f="http://purl.org/atompub/features/1.0"
>              ref="http://purl.org/atompub/features/1.0/supportsDraft" />
> />
>  
> I think it's kind of neat. It's simple and compact. It reminds me of 
> those SAX properties.
>  
> I don't think one can express primitive assertions the same compcat 
> way using a WS-Policy language.
> I don't see it a language limitation but at the same time it seems it 
> would be good if one could go as compact
> as suggested in the Atom draft[1] using the policy language.
>  
> The language has a PolicyReference (and PolicyURIs attribute) but I 
> believe its semantics require the policy engine to dereference the 
> reference.
>  
> So what about introducing, say, a top-level element <PolicyAssertion>.
> It can be used like this, compact form:
>  
> <wsp:PolicyAssertion 
> namespace="http://purl.org/atompub/features/1.0/supportsDraft"
>          xmlns:wsp="http://www.w3.org/ns/ws-policy 
> <http://www.w3.org/ns/ws-policy%22/>"/ 
> <http://www.w3.org/ns/ws-policy%22/>>
>  
> Normalization :
>  
> <Policy>
>    <ExactlyOnce>
>        <All>
>           <ns:PolicyAssertion 
> xmlns:ns="http://purl.org/atompub/features/1.0/supportsDraft 
> <http://purl.org/atompub/features/1.0/supportsDraft%22/>"/ 
> <http://purl.org/atompub/features/1.0/supportsDraft%22/>>
>        </All>
>    </ExactlyOnce>
> </Policy>
>  
> Similarly, a top level Policy(Assertion) attribute is introduced :
>  
> <atom:collection 
> wsp:PolicyAssertion="http://sberyozkin.blogspot.com/2007/09/atom-and-ws-policy.html"/>,
> normalization rules are the same.
>  
> What can it give :
> * more compact way to express simple primitive assertions
>  
> The normalization rule may seem like a hack, not sure about it. 
> Perhaps saying that PolicyReference does not always have to be 
> dereferenced may do the trick.
>  
> Does it make any sense to anyone ?
>  
> This message is not driven by any internal requirements, and I'm not 
> expecting any support for it, but I'd just like experts's opinion on 
> this proposal for the next version of the spec.
>  
> I've tried to motivate it all at [2]
>  
> Cheers, Sergey
>  
> [1] http://tools.ietf.org/html/draft-snell-atompub-feature-10
> [2] http://sberyozkin.blogspot.com/2007/09/atom-and-ws-policy.html
>
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>


-- 
All the best, Ashok

Received on Wednesday, 26 September 2007 21:01:25 UTC