Action-271 (was RE: Are nested assertions part of the policy vocabulary?

Answers to questions from Ashok ...

>Action-271: Pick up the text pointed out by Chris in
>Section 3.2 and answer Ashok's question (by
>reading the letter of the law)

The text in question is from the WS-Policy Framework Section 3.2 [1] -

"When an assertion whose type
is part of the policy's vocabulary
is not included in a policy alternative,
the policy alternative without the assertion type
indicates that the assertion will not be applied
in the context of the attached policy subject."

Let's look at the given example [2],

<Policy>         <!-- V1 -->
  <ExactlyOne>
    <Addressing>
      <Policy/>  <!-- V2 -->
    </Addressing>
    <Addressing>
      <Policy>   <!-- V3 -->
        <AnonymousResponses />
      </Policy>
    </Addressing>
    <Addressing>
      <Policy>   <!-- V4 -->
        <NonAnonymousResponses />
      </Policy>
    </Addressing>
  </ExactlyOne>
</Policy>

In the above policy, there are four distinct policy vocabularies, V1 to V4. V1 contains the Addressing assertion type. In the V1 policy there are three alternatives. The Addressing assertion is included in ALL the three alternatives. The quoted text from the Framework is irrelevant here. You may add another alternative to V1 policy without the Addressing assertion and negation should work just as expected.

The policy vocabulary V2 (of the nested policy) is empty. V3 contains the AnonymousResponses assertion type. V4 contains the NonAnonymousResponses assertion type. In the policy data model, a nested policy is a policy that has at most one policy alternative and is owned by its parent policy assertion. The quoted text from the Framework is irrelevant here because a nested policy has at most one policy alternative.

Onto the questions ...

Q1. Are nested assertions included in the policy's vocabulary? [2]

As illustrated above, assertion types in a NESTED policy are in the policy vocabulary of the NESTED policy.

Q2. If Alternative 1 is selected, does this mean that neither Anonymous responses nor NonAnonymous responses are allowed as both are part of the policy vocabulary but not included in the alternative? [2]

No. As illustrated above, the first alternative indicates the use of WS-Addressing without any restrictions.

We hope this helps.

[1] http://www.w3.org/TR/2007/CR-ws-policy-20070330/#rPolicy_Alternative
[2] http://lists.w3.org/Archives/Public/public-ws-policy/2007Apr/0001.html

Regards,

Asir S Vedamuthu
Microsoft Corporation







From: public-ws-policy-request@w3.org [mailto:public-ws-policy-request@w3.org] On Behalf Of Ashok Malhotra
Sent: Tuesday, April 03, 2007 12:08 PM
To: public-ws-policy@w3.org
Subject: Are nested assertions part of the policy vocabulary?

Section 3.2 of Framework says "When an assertion whose type is part of the policy's vocabulary is not included in a policy alternative, the policy alternative without the assertion type indicates that the assertion will not be applied in the context of the attached policy subject."    Are nested assertions included in the policy's vocabulary?
Consider the following example:
  <wsp:ExactlyOne>
        <wsp:All>
            <wsam:Addressing> <-- supports all response types --> Alternative 1
                <wsp:Policy>
                </wsp:Policy>
            </wsam:Addressing>
        </wsp:All>
        <wsp:All>
            <wsam:Addressing> <-- requires Anonymous responses --> Alternative 2
                <wsp:Policy>
                          <AnonymousResponses />
                </wsp:Policy>
            </wsam:Addressing>
        </wsp:All>
        <wsp:All>
            <wsam:Addressing> <-  requires nonAnonymous responses --> Alternative 3
                <wsp:Policy>
                          <NonAnonymousResponses />
                </wsp:Policy>
            </wsam:Addressing>
        </wsp:All>
    </wsp:ExactlyOne>
</wsp:Policy>
If Alternative 1 is selected, does this mean that neither Anonymous responses nor NonAnonymous responses are allowed as both are part of the policy vocabulary but not included in the alternative.
All the best, Ashok

Received on Saturday, 7 April 2007 01:02:55 UTC