[Feature Request] 'On' option for after_save callbacks

Hi folks!

As per https://github.com/rails/rails/issues/22515, 5.0 saw after_create_commit, after_update_commit, after_destroy_commit being added as aliases to after_commit, on:create, etc. From https://github.com/rails/rails/issues/12502, it seems that on flag only works for after_commit but not after_save.

I was wondering if it would be possible to allow on flag for after_save as well and see similar aliases if that option is implemented? Often times, I have been wanting to trigger those callbacks only on updates and not say create, and haven’t found a clean solution. It also feels consistent in style with the validation callbacks and now after_commit callbacks.

Thank you,


Is not that what after_update does?