Proposal to allow for overriding relationship getter

[lserman]

Hello, please correct me if I am wrong with my assumptions here.

My use-case is that I'd like to use has_one with a has_one_attached object. The issue is that the method on the model always returns this non-nil "proxy" object even when nothing is attached. For example:

class User
  has_one_attached :avatar
end

> User.new.avatar
#<ActiveStorage::Attached::One...

I think I've traced the logic to handle the relationships all the way to this proc: https://github.com/graphiti-api/graphiti/blob/19c75b58017eaf860a5160ff28c0f7dbd3f47674/lib/graphiti/util/serializer_relationships.rb#L75 -- it simply uses public_send to call the association method which leads to issues down the line when a non-nil object is returned but is not backed by any data.

Unfortunately, I did not see a great way to resolve this without overriding the entire data_proc method with a monkey-patch that checks records.attached? and returns nil accordingly.

Is there a built-in way to do this I don't know about, and if not, what would be the preferred approach to allow for custom associations such as this?

[jasonkarns]

@lserman I'm curious if you found a nifty solution or workaround?