Subscription Date Fix

So I wanted to know the date that users were subscribing or unsubscribing to newsletters.

I dove into the database to see if the newsletter subscription table had some sort of updated_at field, and there it was - change_status_at. At first I was joyful, then tears came to my eyes when I saw that the field always contained NULL.

I jumped screens and used the power of Goooogle to divine an answer from the internets. I soon found that others had run into this very issue and went away unanswered. There were even those who claim -

"that it used to work in very old versions of Magento, but doesn't anymore".

At a guess, I think what happened is that the field's definition used to be setup to magically update as a default timestamp (i.e. ON UPDATE CURRENT_TIMESTAMP), but that setting was lost in a past and long forgotten update. So there's no core Magento code that writes to the field because "it didn't have to".

So I put down my beer and put on my trusty Magento Certified Developer's thinking cap and bashed out a quick module that solves the problem by observing changes to the mystical event newsletter_subscriber_save_before and provides the missing date.

Now I'm here to share this solution with the anyone in the Mage Multiverse who might find need of it.