Modified Preorder Tree Traversal - Guidance Request

[Zimzat]

First off I would like to introduce myself. My name is Russell and I
live in a small town in Tennessee in the United States. I first started
programming when my brother introduced me to Visual Basic 3 and I
followed that all the way through Visual Basic 6. After .NET came out I
took a break from programming. When I started programming again I was
tinkering with PHP in phpBB. Since then I've worked on a volunteer web
comic management system, and more recently I recreated an old game
called Xenocid3001 from scratch.

I've been following the Summer of Code this year since I first saw it
on Slashdot. I have looked through all of the development documents on
the Gallery site and loaded a development environment on my local
computer to work with. I also want to use Gallery for my personal site
to manage the dozens of pictures I have uploaded to it over time, so
even if I'm not chosen to work on Gallery I'll still come away with
something I've been looking for.

The idea that caught my eye the most on the idea list is the Modified
Preorder Tree Traversal. I have used the parent-child relationship
method in all of my programming before now so finding an alternative
and quite innovative method was very refreshing. I've already gone
through the tutorial linked to from the idea list and made a class that
implements the method. I've used that to familiarize myself with how it
works. Next I plan on making an extended class that can import existing
tables into the MPTT method.

My idea is to try to adapt the existing code to handle the various
issues mentioned in the idea list about locking, permissions, and
what-not. If that wouldn't work then I would go ahead and create new
models and methods for handling the back-end of using the MPTT
algorithm.

This is where I could use some assistance from the Gallery developers.
I've looked through the codex documentation and API pages, but I'm
still not sure where to start looking at the Gallery code. If I knew
where to start with relevant code I'm sure I could figure out where to
go from there. If anyone could point me in the right direction I would
be very grateful.

Sincerely,
Russell

[bharatman]

Here's a link to a few emails on the -devel mailing list where we've
discussed MPTT:
http://sourceforge.net/search/?type_of_search=pervasive&exact=1&group_id=7130&words=mptt&Search=Search

Hope that helps. I'd suggest that you look at the various API methods
which go after the parent/child and ancestor/child relationships. If
you find those methods in GalleryCoreApi and then follow through to the
helper class that implements them, you can get an idea of how we're
implementing the adjacency relationship currently.