Run method if association does not exit

Hello people,

Please advice with, I have some models and they have feeds, feed is a small presenter for different types of content.

class Feed    belongs_to :attachable, :polymorphic => true end

class Song has_one :feed, :as => :attachable end

class Gallery has_one :feed, :as => :attachable end

So when I call on some_song.feed, and there is no such feed for that song, I want to create it inside Feed model

You can create by Song.feed.create(:parameters => value)

Vitaliy Yanchuk wrote in post #1013290: