Thanks for everyone's input. I did finally figure out how to modify WADispatcher, WAFileHandler and WAExternalFileLibrary to do exactly what I need. My modification permits a folder anywhere on the disk to be the root for publicly served files, and it supports arbitrarily nested subfolders. It really wasn't hard to write once I understood where to look, and your assistance helped me to figure that out. Once I wrote this modification I was able to use my application code as written for Seaside 2.6 and Web Toolkit on top of Seaside 2.8 and Opentalk without modification.
For example the following URL resolves to a file in the public folder
http://localhost:7777/myGraphic.png
And the following resolves to a file in a subfolder named 'other':
http://localhost:7777/other/yourGraphic.png
Of course if the folder/file isn't found it produces a 404 as it should.
The code is a little hack-ish as it is now, but I'll clean it up when I get a chance and make it available for others. So thanks again. :-)
-Carl Gundel http://www.runbasic.com
seaside@lists.squeakfoundation.org