Mailing-List: contact directory-dev-help@incubator.apache.org; run by ezmlm
Precedence: bulk
Reply-To: "Apache Directory Developers List"
 <directory-dev@incubator.apache.org>
Subject: Re: [eve] merlin wrappers
From: Alex Karasulu <aok123@bellsouth.net>
To: Apache Directory Developers List <directory-dev@incubator.apache.org>
In-Reply-To: <40E78173.3040504@hedhman.org>
References: <1088780218.16055.7.camel@fermi.trunk.joshua-tree.org>
	 <40E5AD68.4020804@apache.org>
	 <1088803962.17994.4.camel@fermi.trunk.joshua-tree.org>
	 <40E6049F.4080601@apache.org>
	 <1088906607.649.84.camel@fermi.trunk.joshua-tree.org>
	 <40E78173.3040504@hedhman.org>
Content-Type: text/plain
Message-Id: <1088922069.1095.6.camel@fermi.trunk.joshua-tree.org>
Mime-Version: 1.0
Date: Sun, 04 Jul 2004 02:21:09 -0400
Content-Transfer-Encoding: 7bit

On Sun, 2004-07-04 at 00:02, Niclas Hedhman wrote:
> Alex Karasulu wrote:
> 
> > On Fri, 2004-07-02 at 20:58, Stephen McConnell wrote:
> 
> >>This has some very heavy implications.  Assume for 
> >>a moment that you expose commons lang 2.0 and avalon framework 4.1.5 as 
> >>part of your API.  Let's also assume that (a) your running as an 
> >>embedded component inside another system that you know nothing about - 
> >>and lets assume that the embedder is running framework 4.2, secondly, 
> >>lets assume that your running a plugin of some kind inside eve that 
> >>assumes commons lang 1.0.
> > 
> > 
> > So for fun we presume our eve-frontend jar contains the classes in 
> > commons-lang-2.0.jar and avalon-framework-4.1.5.jar "as part of [our]
> > API".  
> 
> Nooooooo....  :o)  I think you misunderstood Stephen (below seems to 
> indicate the opposite).
> He means that the API does not contain the AF4 classes, and does not 
> depend on them either.
> He means that the container should only expose what is absolute 
> necessary to its 'children' or managed parts. Classes that are part of 
> the container's implementation and extension mechanisms should be in a 
> different branch.

I thought Steve was simply trying to make a point without having to
reference exact classes in the eve frontend.  Even if he was not and I'm
mistaken I think the conclusion is still correct in that we should
separate the API from the implementation.

<snip/>

> > Going on the "embedder", which is the application setting up Eve and
> > loading the eve-frontend.jar via some ClassLoader.  This application's
> > ClassLoader which is the parent of the ClassLoader with
> > eve-frontend.jar, has avalon-framework-4.2.jar loaded into it.  So we
> > have the following situation:
> 
> The 'embeddor' should probably not have the avalon framework exposed 
> either, unless it is an Avalon capable top-level container (such as 
> Merlin). If Eve is configured to run in the Avalon specific container, 
> then it relies on the embeddor's classloader for the AF4 classes.

Right I would tend to agree.  Keep in mind a lot of this conversation
was hypothetical.  Perhaps Steve can clarify some of this when he
awakens.

Alex