module ActiveRecord module Associations class Preloader module ThroughAssociation #:nodoc: def through_reflection reflection.through_reflection end def source_reflection reflection.source_reflection end def associated_records_by_owner through_records = through_records_by_owner ActiveRecord::Associations::Preloader.new( through_records.values.flatten, source_reflection.name, options ).run through_records.each do |owner, records| records.map! { |r| r.send(source_reflection.name) }.flatten! records.compact! end end private def through_records_by_owner ActiveRecord::Associations::Preloader.new( owners, through_reflection.name, through_options ).run Hash[owners.map do |owner| through_records = Array.wrap(owner.send(through_reflection.name)) # Dont cache the association - we would only be caching a subset if (preload_options != through_options) || (reflection.options[:source_type] && through_reflection.collection?) owner.association(through_reflection.name).reset end [owner, through_records] end] end def through_options through_options = {} if options[:source_type] through_options[:conditions] = { reflection.foreign_type => options[:source_type] } else if options[:conditions] through_options[:include] = options[:include] || options[:source] through_options[:conditions] = options[:conditions] end through_options[:order] = options[:order] end through_options end end end end end