On Tue, Jun 21, 2011 at 2:05 PM, Simon Laws <simonsl...@googlemail.com> wrote:
>> The spec could certainly stand to be a bit more explicit here. :) It
>> does seem to make more sense to limit it to bindings and
>> implementations, so I agree that we should look into changing the
>> appliesTo builder. I do notice there are several compliance tests
>> using @appliesTo attributes that specify service, component, or
>> composite, though (POL_4005 through 4009.)
>>
>
> Ok, that's interesting. I think we should check with OASIS before
> making further changes. I'll see if I can track down someone.
>
> Simon
>
> --
> Apache Tuscany committer: tuscany.apache.org
> Co-author of a book about Tuscany and SCA: tuscanyinaction.com
>
Ok, I just checked with Dave Booz from the policy spec team and the
intention is the following:
- the attachTo and appliesTo processing are independent
- it is binding implementations or implementation type implementations
that act on attached policysets after attachTo and appliesTo have been
resolved
- the appliesTo XPath expression can point to elements other than
bindings or implementation elements in which case you look to the
child elements to find a binding or implementation element
So, from POL_4005
<policySet name="Qual1PolicySet"
provides="test:testImplIntent.qual1" appliesTo="//service"
attachTo="//sca:component[@name='TEST_POL_4005Component1']/sca:service[@name='Service1']">
<!-- This policy intentionally left blank -->
</policySet>
This policySet appliesTo all of the bindings of all of the services in
the composite.
- you could configure a policy set so that it applies to
implementations and bindings, e.g. set appliesTo to point to a
component, but this is likely to lead to errors as policy sets will
normally be specific to an implementation or a binding. Having said
that in Tuscany the runtime can still treats policy sets somewhat
independently to add generic interceptors to wires so we may still
want to maintain this ability as an extension to the specs
So in short we do need to rework the appliesTo processing.
Regards
Simon
--
Apache Tuscany committer: tuscany.apache.org
Co-author of a book about Tuscany and SCA: tuscanyinaction.com
