How should I maintain my object modules in Perl?

Question

I'm writing some object module in Perl using Moose. I use to store instances of created objects then use them.

The basic representation of my object's data remains the same, but from time to time I add more functionalities - e.g. class methods or object methods.

Can I continue using my stored objects, which were created with an earlier version of the module, with the new functionalities? Or must I create the objects again every time I change the module?

What is the common paradigm for developing an object module where the basic data structure does not change but functionalities do?

Answer 1

As long as the data structure doesn't change, you should be fine: the data is slurped and reblessed into your class' namespace: this ensures new methods would be available on that data.

BEWARE changing the data structure though!

I don't see much wrong with it, although for some uses you could just use a database to store your data, and access it in a OO fashion using one of the many ORM (DBIx::Class, Fey::ORM or whichever).

Answer 2

Give KiokuDB a whirl. It might be just what you want; according to the site linked:

"KiokuDB is a Moose based object oriented persistence frontend for a number of storage backends."

Answer 3

I second the recommendation for looking at KiokuDB.

In addition to transparent serialization of Moose objects to a graph store, it also has a facility for handling transitions between Class versions. Effectively you can define a translation routine to go from version 0.1 to 0.2 of your class and hand the migration off to it. KiokuDB will execute this routine and allow you to re-store the result.