> -----Original Message-----
> From: Stephen McConnell [mailto:[EMAIL PROTECTED]
>
> Nope - the intention is to replace it with something that passes a
> DeploymentModel instance instead of an Appliance.  The problem with
> passing an appliance is that it exposes too much info to the extension.
> Secondly, there has been some shuffling of things around at the level of
> the kernel - now the kernel creates a root container and I'm thinking
> about how we can use this to locate privaliged componenents (such as
> extensions).  One of the issues you should aware of is that if you
> deploy an extension with access to a model, we need Merlin to provide
> the privaliged classloader.  Currently the classloader provides nothing
> more than the APIs and privaliged content needs the SPIs as well.  This
> means when Merlin locates an extension - it needs to provide the
> extension with an extended classloader.

After some more digging, I have some other thoughts/questions about this
idea:

1. Extension Scope:

  What is the scope for an extension (lifecycle or otherwise)?  Is it
  only within its container and sub-containers?  Can extensions be 
  allowed to handle _all_ components?

2. Extension Declaration:

   Should an extension be declared within the container declaration
   (ie- in the block.xml) or can/should extensions be declared at the
   kernel level (in the kernel.xml or in some /ext directory).

3. Extension Hooks:

   At what point should extensions be allowed?  Deployment?  Component
   Access?  Shutdown?

4. Extension Architecture:

   At one point ideas where thrown around about using an Event based 
   extension API (which I think is cool).  Alternatively we could
   use an Interceptor approach or something like Excalibur Lifecycle.


As for the classloader issue, do blocks get a privileged classloader?  Does
anything currently get a privileged classloader?

Extensions I'm currently interested in include:  JNDI (via AltRMI perhaps?),
JMX, and JMS.  I had a JMS extension working for the older Merlin version
and I want to get it up to date for Merlin 3.0 before I release.  What about
JMX, I know there was work being done for JMX in merlin, but I haven't seen
much in CVS lately (perhaps I'm looking in the wrong places).

Thanks.

J. Aaron Farr
  SONY ELECTRONICS
  DDP-CIM
  (724) 696-7653


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