why does extension-helper deprecate definition of ExtentionPoints in Implementation/Binding activators

[lee zhenghui <le...@gmail.com>]

Hi,
   extension-helper module is simplifying implementation/binding extention
development. But Why it deprecate definition of ExtentionPoints in
Implementation/Binding activators.  Java implementation have defined a class
visitors extention points in the activator, do you want to replace "
org.apache.tuscany.sca.core.ModuleActivator" with "
org.apache.tuscany.sca.spi.ImplementationActivator" for java implementation?

     If yes, Where is the  pretty  runtime point to registry these
extension  points?
     If no,  Java implementation looks a little different than other
implementations.  maybe a little confused to new comer(java implementation
is a good entry point to learn sca implementation extension)

  Maybe I missed something here, pls correct me.
-- 
Thanks & Best Wishes
-----------------------------------
Zhenghui Li(李正辉)

Re: why does extension-helper deprecate definition of ExtentionPoints in Implementation/Binding activators

[ant elder <an...@apache.org>]

On 6/11/07, lee zhenghui <le...@gmail.com> wrote:
>
> Hi,
>    extension-helper module is simplifying implementation/binding extention
> development. But Why it deprecate definition of ExtentionPoints in
> Implementation/Binding activators.  Java implementation have defined a
> class
> visitors extention points in the activator, do you want to replace "
> org.apache.tuscany.sca.core.ModuleActivator" with "
> org.apache.tuscany.sca.spi.ImplementationActivator" for java
> implementation?
>
>      If yes, Where is the  pretty  runtime point to registry these
> extension  points?
>      If no,  Java implementation looks a little different than other
> implementations.  maybe a little confused to new comer(java implementation
> is a good entry point to learn sca implementation extension)
>
>   Maybe I missed something here, pls correct me.


Just to be clear, extension-helper is not deprecating the existing runtime
SPI. The existing runtime SPI continues to be perfectly fine to write
implementation extensions with. The extension-helper module is the start of
a simpler SPI for binding and implementation extensions as those type of
extension will not usually need the full power and flexibility of the full
Tuscany runtime SPI.

Be interesting to hear other opinions, but I'm not sure that
implementation.java really needs to or should be using the ExtensionPoint
mechanism (getExtensionPoints) to add its classVisitors. This ends up making
the class visitors available to everything in the runtime which doesn't seem
ideal. I think its just done like this as a hang over from the old runtime
code.

The extension-helper module is still being worked out, if you've suggestions
(or patches :) ) on how to improve it or use cases showing its deficiency's
that would be really helpful. If you'd really find the getExtensionPoints
facility useful say and we can look at adding it.

   ...ant