Hi Miguel,
The add-on mechanism isn't quite finished yet I'm afraid, but Richard Rodgers & I (release coordinators for 1.4) count it as a 'must have' for 1.4.  You're right, there are some final details and decisions to be hammered out.  Richard Jones has done a lot of work on this to produce a prototype add-on but there's still some work to do, so I'm afraid I can't really point you at an example or clear documentation right now.
Please feel free to jump in and tell us if you think the approaches we've described are good ones, and if you have any suggestions.  In the meantime, there are some things you could be doing to prime your feature for inclusion, i.e. add the i18n, XHTML and WAI compliance.  Your add-on looks nicely separated from the rest of the system (e.g. it uses its own separate database tables) so refactoring to follow the add-on structure should be a very small amount of work, once that structure is finalised.
Thanks for being so responsive and I hope we can get all this done and include this great feature soon!

From: Miguel Ferreira [mailto:mferreira@dsi.uminho.pt]
Sent: 16 December 2005 05:13
To: 'DSpace Developer List'
Cc: Tansley, Robert
Subject: Add on Mechanism... a few questions...

Dear Robert,
I took a look at the "Add on Mechanism" wiki page and I was left with a few questions...
- Is the addon mechanism already in place? Does the CVS head implent it?
- I got the feeling that there are still a couple of unsettled alternatives on how to structure and place the add-on. Should I create an alternative project tree for the add-on with all the necessary config files, sql scripts, libs, sources, etc...?
- Where is the "addons.properties" config file that activates the add-on?
- The namespaced tables should follow the pattern "x_researcher_folder". Should X be replaced by the name of the add-on?
- How should I name the add-on Java packages? org.dspace.*?
- Are there any examples that I could follow?
Thank you.
Best regards,
- -
Miguel Ferreira (researcher)
Department of Information Systems
University of Minho
Campus de Azurém
4800-058 Guimarães, Portugal
Phone: +351 253 510 261 / FAX: +351 253 510 300 / Ext.: 3261