Re: [Guidelines] NEW ISSUE 4198: Policy assertion semantics independent of attachment mechanism

I received some suggestions from Umit to make the proposed text in the 
guidelines clearer. As a result, I rephrased the sentence on 
constraining attachment to policy subjects. We hope this makes the text 
easier to understand:


Title

Policy assertion semantics independent of attachment mechanism

Description

A policy can be attached to a policy subject as external attachment, directly
included, or referenced by the policy subject. The assertions contained in the
attached policy maintain their semantics independent of the chosen attachment
mechanism. The guidelines should make that explicit.

Justification

Assertion authors are constrained from designing assertions that change their
semantics based on the attachment mechanism. Policy tools must have the liberty
to choose the most appropriate or feasible attachment mechanism at any time
without having to analyze the contents of the attached policy.

Target

Guidelines for Policy Assertion Authors

Proposal

Include in the Guidelines section 4.1:

WS-PolicyAttachment provides various mechanisms to attach a policy to a policy
subject. Although a policy assertion may be tailored for a specific set of
policy subjects by design, its semantics do not depend on the mechanism by
which a policy is attached to a policy subject. Independence from a specific
attachment mechanism allows policy tools to choose the most appropriate
mechanism to attach a policy without having to analyze the contents of the
policy.





Fabian Ritzmann wrote:
> http://www.w3.org/Bugs/Public/show_bug.cgi?id=4198
>
>
>         Title
>
> Policy assertion semantics independent of attachment mechanism
>
>
>         Description
>
> A policy can be attached to a policy subject as external attachment, 
> directly included, or referenced by the policy subject. The assertions 
> contained in the attached policy maintain their semantics independent 
> of the chosen attachment mechanism. The guidelines should make that 
> explicit.
>
>
>         Justification
>
> Assertion authors are constrained from designing assertions that 
> change their semantics based on the attachment mechanism. Policy tools 
> must have the liberty to choose the most appropriate or feasible 
> attachment mechanism at any time without having to analyze the 
> contents of the attached policy.
>
>
>         Target
>
> Guidelines for Policy Assertion Authors
>
>
>         Proposal
>
> Include in the Guidelines section 4.1:
>
> WS-PolicyAttachment provides various mechanisms to attach a policy to 
> a policy subject. Independent of the employed attachment mechanism, 
> constraints may be defined to which policy subject an assertion may be 
> attached [Web Services Policy Framework, section 3.4]. The semantics 
> of a policy assertion may not depend on the mechanism by which a 
> policy is attached to a policy subject. This allows policy tools to 
> choose the most appropriate mechanism to attach a policy without 
> having to analyze the contents of the policy.
>
> -- 
> Fabian Ritzmann
> Sun Microsystems, Inc.
> Stella Business Park             Phone +358-9-525 562 96
> Lars Sonckin kaari 12            Fax   +358-9-525 562 52
> 02600 Espoo                      Email Fabian.Ritzmann@Sun.COM <mailto:Fabian.Ritzmann@Sun.COM>
> Finland