require 'active_support/core_ext/object/inclusion' module ActiveRecord::Associations::Builder class BelongsTo < SingularAssociation #:nodoc: self.macro = :belongs_to self.valid_options += [:foreign_type, :polymorphic, :touch] def constructable? !options[:polymorphic] end def build reflection = super add_counter_cache_callbacks(reflection) if options[:counter_cache] add_touch_callbacks(reflection) if options[:touch] configure_dependency reflection end private def add_counter_cache_callbacks(reflection) cache_column = reflection.counter_cache_column name = self.name method_name = "belongs_to_counter_cache_after_create_for_#{name}" mixin.redefine_method(method_name) do record = send(name) record.class.increment_counter(cache_column, record.id) unless record.nil? end model.after_create(method_name) method_name = "belongs_to_counter_cache_before_destroy_for_#{name}" mixin.redefine_method(method_name) do record = send(name) record.class.decrement_counter(cache_column, record.id) unless record.nil? end model.before_destroy(method_name) model.send(:module_eval, "#{reflection.class_name}.send(:attr_readonly,\"#{cache_column}\".intern) if defined?(#{reflection.class_name}) && #{reflection.class_name}.respond_to?(:attr_readonly)", __FILE__, __LINE__ ) end def add_touch_callbacks(reflection) name = self.name method_name = "belongs_to_touch_after_save_or_destroy_for_#{name}" touch = options[:touch] mixin.redefine_method(method_name) do record = send(name) unless record.nil? if touch == true record.touch else record.touch(touch) end end end model.after_save(method_name) model.after_touch(method_name) model.after_destroy(method_name) end def configure_dependency if options[:dependent] unless options[:dependent].in?([:destroy, :delete]) raise ArgumentError, "The :dependent option expects either :destroy or :delete (#{options[:dependent].inspect})" end method_name = "belongs_to_dependent_#{options[:dependent]}_for_#{name}" model.send(:class_eval, <<-eoruby, __FILE__, __LINE__ + 1) def #{method_name} association = #{name} association.#{options[:dependent]} if association end eoruby model.after_destroy method_name end end end end