Activerecord - callback after saving all related objects

Question

I have a model and I would like to keep the identifiers of related objects (denormalize) for performance reasons. I have a method that looks like this:

def cache_ids
  self._tag_ids = self.tag_ids
end

I thought I could just run it on before_save, however there is a problem - some of the related objects may be new entries and therefore they will not have identifiers.

Then I switched to after_save, but apparently this callback also starts before the transaction is completed, so the identifiers are not set yet.

At the moment, I am done with:

def save_with_idcache(*args)
  return false unless save_without_idcache(*args)

  cache_ids

  return save_without_idcache(false)
end

alias_method_chain :save, :idcache

It seems to work, but it does not look very elegant.

Is there a better way? For example, does a callback persist after saving an object and related objects?

, - .

Answer 1

- _tag_ids after_create, after_save ( / ) after_destroy.

, , , , .

Answer 2

after_create? .

after_create :idcache
before_save :idcache

protected
def idcache
  unless new_record?
    ...
  end
end