blob: a62815830c3e3b9f07e8843c8581e0687cea6675 (
plain) (
tree)
|
|
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
@loaded = true
return @associated_records_by_owner if @associated_records_by_owner
left_loader = Preloader.new(owners,
through_reflection.name,
through_scope)
left_loader.run
should_reset = (through_scope != through_reflection.klass.unscoped) ||
(reflection.options[:source_type] && through_reflection.collection?)
through_records = owners.map do |owner, h|
association = owner.association through_reflection.name
x = [owner, Array(association.reader), association]
# Dont cache the association - we would only be caching a subset
association.reset if should_reset
x
end
middle_records = through_records.map { |rec| rec[1] }.flatten
preloader = Preloader.new(middle_records,
source_reflection.name,
reflection_scope)
preloader.run
middle_to_pl = preloader.preloaders.each_with_object({}) do |pl,h|
pl.owners.each { |middle|
h[middle] = pl
}
end
@associated_records_by_owner = through_records.each_with_object({}) { |(lhs,middles,assoc),h|
x = middle_to_pl[middles.first]
rhs_records = middles.flat_map { |r|
r.send(source_reflection.name)
}.compact
if x && x.loaded?
rs = rhs_records.sort_by { |rhs|
x.preloaded_records1.index(rhs)
}
else
rs = rhs_records
end
h[lhs] = rs
}
end
private
def through_scope
scope = through_reflection.klass.unscoped
if options[:source_type]
scope.where! reflection.foreign_type => options[:source_type]
else
unless reflection_scope.where_values.empty?
scope.includes_values = Array(reflection_scope.values[:includes] || options[:source])
scope.where_values = reflection_scope.values[:where]
end
scope.references! reflection_scope.values[:references]
scope.order! reflection_scope.values[:order] if scope.eager_loading?
end
scope
end
end
end
end
end
|