Issue 15: External Policy Attachment

[ashok malhotra <ashok.malhotra@oracle.com>]

Two comments on Mike Edwards' proposal that we started discussing yesterday:
http://lists.oasis-open.org/archives/sca-policy/200809/msg00015.html

1. Oracle Usecase
Policy artifacts are stored in a database.  They have a completely 
different management structure and
lifecycle than implementations.  All implementations have access to this 
database and policies from the
database are applied before implementations are deployed.

Thus, in our language, the implementer can merely specify intents and 
has to do nothing more.
The concrete policies are pulled from the database at deployment time.

Thus, while I am sympathetic to the IBM proposal to remove or limit the 
pull model we need
to enable this usecase.  Specifically, we need to be able to associate a 
collection of policies with
a composite or contribution in a very simple manner.

2. Allow policies to be attached  using  External Attachment

A policySet has the following structure:

<policySet name="NCName"

provides="listOfQNames"

appliesTo="xs:string"

attachTo="xs:string"

xmlns=http://www.osoa.org/xmlns/sca/1.0

xmlns:wsp="http://schemas.xmlsoap.org/ws/2004/09/policy";>

...

<xs:any>*

</policySet>


The <xs:any> allows WS-Policies or other policies to be included within 
a policySet.
When used with External Attachment the @provides is not useful as we 
specify where the policySet applies
rather than having it replace an intent.  The @appliesTo and @attachTo 
are also not useful as the policyAttachment
element specifies where the policySet is to be attached.


So, why don't we allow policies to be attached directly, without the 
baggage of the policySet wrapper?
This simplifies things and also allows legacy apps which use policies 
directly to be brought into the SCA fold.


The earlier versions of the proposal that I wrote had this feature but 
Mike seems to have removed it in
his latest version.  I would request that it be reinstated.


-- 
All the best, Ashok