rails/rails — pull request #5412 by tilsammans (2012-03-13 15:25:25+00:00)
Title: Remember the stored attributes in a config attribute. 

This allows you to retrieve the list of attributes you've defined.
Usable for e.g. selects in the view, or interators based on the
attributes you wish to store in the serialized column.

It follows the serialize API, with its serialized_attributes hash.