My app has feeds and items. Users can subscribe to feeds, which I track in a Subscription class.
I wanted an association for all of a user’s unread items:
class Subscription < ActiveRecord::Base
belongs_to :feed
belongs_to :user
has_many :unread_items, :through => :feed, :source => :items, :conditions => proc {
“not exists ( select * from readings where readings.item_id = items.id AND readings.user_id = #{user_id} )”
}
…
This works fine if I reference it directly (i.e, @user.subscriptions.first.unread_items). But if I try to eager load or join against it:
eager load: ‘self’ in the conditions proc refers to the intermediate object (here, the Feed class) which I don’t think is expected. Crashes because Feed obviously has no user_id in my app.
join: ‘self’ in the conditions proc refers to a JoinDependency object, which seems totally wrong.