I have a drupal commerce site built with several thousand products. The products are maintained through Feeds. Unfortunately a new requirement has reared its head that I am trying to work around.

I have the requirement to disable products that are not included in an import. That is, I cannot rely on an import to contain an outdated product, rather I need use the absence of an item to determine that it is no longer available.

I'm a little at a loss if I should be handling this from the feeds side - Having some sort of callback to check date of last change then do a database operation based upon that - or from some sort of custom report/maintenance script.

The feeds update are manual uploads, so if need be I can require the uploader to do some other action, this won't be a cron type thing.

Any ideas?