Re: [DISCUSS] Declaring extensions as being available in the domain

[Raymond Feng]

I share the same concerns as Sebastien raised. Mixing the policy definitions 
with tuscany runtime extensions in one file doesn't seem to be right. For 
example, we could have two tuscany extensions to support binding.ws, one is 
based on Axis2 while the other one is based on CXF. With the current 
approach, we will see three files:

definitions.xml for binding.ws bindingType which is independent of the 
underlying ws stack
two META-INF/services/... files, one for binding-ws-axis2 and the other for 
binding-ws-cxf

With the new proposal, I cannot achieve the pluggability unless we duplicate 
the bindingType info for binding.ws in two definitions.xml.

Thanks,
Raymond
--------------------------------------------------
From: "Jean-Sebastien Delfino" <[EMAIL PROTECTED]>
Sent: Monday, May 12, 2008 1:56 PM
To: <tuscany-dev@ws.apache.org>
Subject: Re: [DISCUSS] Declaring extensions as being available in the domain

Venkata Krishnan wrote:
Hi Ant,

Yes, this sounds good to me - that will make all meta-data related to an
extension available in just one place.

- Venkat


What i was thinking of was along the lines of adding Tuscany specific 
xml
to
the definitions file that replaces everything we currently put in the
meta-inf/services files for binding and implementation extensions, eg
something like:

<definitions xmlns:tuscany="http://tuscany.apache.org/xmlns/sca/1.0"; ... 
 >

  <bindingType type="binding.ws" ... >

     <tuscany:binding

providerFactory="org.apache.tuscany.sca.binding.ws.axis2.Axis2BindingProviderFactory"

model="org.apache.tuscany.sca.binding.ws.WebServiceBinding" />

  </bindingType>

</definitions>


IMHO this is mixing different concerns that should be kept independent:

- domain != runtime
- policy definitions != runtime extensions
- application level definitions != system definitions

If you don't like the current META-INF/services approach and really want 
to change all that, I'd suggest to come up with a proper extension 
mechanism, independent of SCA policy definitions, something like OSGi for 
example would be more suitable for this.

--
Jean-Sebastien