I'm trying to create a method that will automatically create something I can save and use later, which will let me automate data migration from one version of a class to the next.
When I compile a normal persistent class, a "storage" gets created, and I would like to be able to archive some code that would let me recreate this "old storage" so I could access an "older version" from a global and map the values into the current mapping of the class. I have objectgenerator methods that will save a version with every record, and detect if the "current version" of the class code is different from the version saved in the data record itself, but I'm not sure how to retain what the "old" version actually looked like so I can auto-migrate the data from the "old to the new". To do this, I'm thinking that being able to read what the current storage is at compile time, I should be able to save that value elsewhere and create a durable "version reader" so I can migrate the data forward without having to actually have the programmer do the work.
Does this seem like a reasonable approach? and if so, can anyone point me to where, at compile time, the storage values are so I can do the saving of the data?
(or should I be looking at cloning some part of the generated %Save() method chain at compile time to a version specific save attached to "something else" (not sure what, but 'something'))