Mailing-List: contact dev-help@avalon.apache.org; run by ezmlm
Precedence: bulk
Reply-To: "Avalon Developers List" <dev@avalon.apache.org>
Message-ID: <3FDF4F9D.7070104@apache.org>
Date: Tue, 16 Dec 2003 19:31:57 +0100
From: Stephen McConnell <mcconnell@apache.org>
User-Agent: Mozilla/5.0 (Windows; U; WinNT4.0; en-US; rv:1.4) Gecko/20030624
MIME-Version: 1.0
To: Avalon Developers List <dev@avalon.apache.org>
Subject: Re: [MERLIN]How to get a global lookup for services?
References: <8538F0205935D411A7D100508BAC128901983954@DIANA>
In-Reply-To: <8538F0205935D411A7D100508BAC128901983954@DIANA>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 8bit


Hi Peter:

See notes in-line.


pnb@scancoin.se wrote:

>Hi,
>we are looking a bit closer at the service configuration of Merlin. It seems
>that every component get's it's own ServiceManager that provides the
>declared dependencies to the component.
>
>Is there a way to look up components at runtime, e.g. by
>"container/component", that are not in the ServiceManager? 
>

No.

The keys handled by the the service manager are aligned directly with 
the @avalon.dependency tags for the component to which the service 
manager is assigned.

>Or is JNDI etc. used for that?
>
>It seems that in the block.xml you can only override already declared
>dependencies, not insert any new ones?
>

Correct.

If you were inserting new deependecies - you would do this at the level 
of the type (i.e. under the xinfo - or equivalent @avalon.dependency). 
If your component needs to aquire something dynamic - then your 
component should be declaring a dependency on some application specific 
finder service.  The implementation of that finder service could do some 
intertesting things with an embedded kernel - but that's another thread.

>How can you add a dependency after the SM is finished (e.g. when the
>configuration on a component is called?)
>

You cannot - you can only get the depedency you declare at the level of 
the type.
This is intentional - if you want to step outside of this constraint you 
need to be thinking about a service that provides the discovery 
semantics that you are thinking of.

What is the "discovery scenario" your dealing with?

Cheers, Steve.


>
>Thanks
>
>/peter
>
>------------
>Peter Neubauer
>Software Manager
>ScanCoin AB
>J�gershillgatan 26
>213 75 Malm� /Sweden
>
>Phone:  +46 40 6000 687
>mail: pnb@scancoin.se 
>
>  
>
>------------------------------------------------------------------------
>
>---------------------------------------------------------------------
>To unsubscribe, e-mail: dev-unsubscribe@avalon.apache.org
>For additional commands, e-mail: dev-help@avalon.apache.org
>

-- 

Stephen J. McConnell
mailto:mcconnell@apache.org

|------------------------------------------------|
| Magic by Merlin                                |
| Production by Avalon                           |
|                                                |
| http://avalon.apache.org/merlin                |
| http://dpml.net/                               |
|------------------------------------------------|


---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@avalon.apache.org
For additional commands, e-mail: dev-help@avalon.apache.org