I only have superficial familiarity with Pier and
WikiServer: as far
as I can tell, the persistency code uses MAExternalFileModel, but
sadly I can't guess if the effect is available to all Pier developers,
or proprietary to WikiServer.
All uploaded files are handled externally to the image using
MAExternalFileModel, unless you changed the default to use
MAInternalFileModel. This is part of Magritte and has been in use for
many years already. These file-models are only used by Pier for
uploaded files though. MAExternalFileModel essentially models a
ByteArray that is external to the image and that can be served through
Apache. I don't think that MAExternalFileModel is useful to persist
the rest of the Pier model, but there are always surprises :-)
Lukas
--
Lukas Renggli
http://www.lukas-renggli.ch