Long time reader, first time poster. Please forgive me if this post is hard to follow, it is hard for me to explain.

I am currently the sole developer on a PHP5 based project using Propel and Mojavi. This application will track all information (from IP addresses and netgroups to physical location and points-of-contact) related to a host (computer) for the UNIX sysadmin group in my company. This information is saved into a database from which our NIS maps and reports are generated. I am making great progress using the Propel generated DB accessor classes. Which leads me to my question...

I have a requirement to add history for each insert/update/delete to the database. The requirement further states that a history "event" must record the old value as well as the new value for an "object". For example, when updating a NetworkDevice for a Host, the corresponding History "event" should look like this:

----
Updated Network Device:

Updated IP Address from 192.168.1.100 to 192.168.1.101
Updated Host Name from foo.mycompany.com to bar.mycompany.com
Updated Is Primary from No to Yes
----

Using the isNew(), isDeleted() and isModified() methods provided by Propel I am able to find the state of an object easily. I can even get a list of the attributes that were modified. How would I go about creating a mechanism for adding a history functionality to each of my DB accessor classes?

I don't want to have to create a method generateHistory() or something like that for each of my 18+ classes. I looked into using a Decorator pattern or Visitor pattern but they both seem to a misuse of my intended application.

Any help is greatly appreciated. If more detail/info is required please let me know. Thanks!