The project page mentions ideas are welcome so here we go:

Not sure if this module can already do this, but I was inspired by
http://drupal.org/node/1240366

I'm thinking Rules integration could take this to the next level:
- based on availability in the feed fire a Rule Event
- based on change of a certain value in the feed execute a Rule Event

This would allow us to
- manipulate field values (and published/unpublished status) based on availability in a feed or value change
- send email alerts based on availability in a feed or value change of a field
- schedule another feed import based on availability in the feed or value change
- etc

realworld usecases like
- the product is not available in the feed anymore, set to unpublished or change field value to 'out of stock'
- a price has changed, set the 'recent price change flag'
- etc

Comments

derhasi’s picture

derhasi commented
Status: Active » Postponed (maintainer needs more info)

As there is no history of the former imports, you only can compare former values by storing your values to nodes or other entites, and then compare the new data against the stored entity. That can be done at the feed import, so there is no need for a new action or event.

If your can rely on a frequent import, you could set all nodes, that haven't ben updated in the last x days, to unpublished. For that you can use a scheduled rule with views_bulk_operations and views.