Skip validation of associated objects unless nested attributes have been provided

activerecord_nested_attributes_patch.rb

module ActiveRecord
  module NestedAttributes
    module ClassMethods

      # Skips validation of associated objects unless nested attributes have been provided.
      #
      # This is a horrid workaround for the fact that nested_attributes_for sets the autosave
      # option for each assocation to true, which causes validation to fail for associated
      # objects that have been loaded, whether any nested attributes have been provided or not.
      # This causes problems with the parent object is updated from forms that don't include
      # the nested attributes, and therefore don't allow the validation errors to be rectified.
      #
      # Note: at the moment, this method does too much - it also creates an attribute reader
      def skip_validation_unless_attributes_provided_for(*attr_names)
        attr_names.each do |association_name|
          # attr_reader :pirate_attributes
          # alias_method :assign_pirate_attributes, :pirate_attributes=
          # def assign_and_record_pirate_attribues(attributes)
          #   @pirate_attributes = attributes
          #   assign_pirate_attributes(attributes)
          # end
          # alias_method :pirate_attributes=, :assign_and_record_pirate_attribues
          # before_validation do
          #   if self.pirate_attributes.nil?
          #     class << self.agency
          #       def valid? ; true ; end
          #     end
          #   end
          # end
          class_eval <<-eoruby, __FILE__, __LINE__ + 1
            attr_reader :#{association_name}_attributes
            alias_method :assign_#{association_name}_attributes, :#{association_name}_attributes=
            def assign_and_record_#{association_name}_attribues(attributes)
              @#{association_name}_attributes = attributes
              assign_#{association_name}_attributes(attributes)
            end
            alias_method :#{association_name}_attributes=, :assign_and_record_#{association_name}_attribues
            before_validation do
              if self.#{association_name}_attributes.nil?
                class << self.#{association_name}
                  def valid?(context = nil) ; true ; end
                end
              end
            end
          eoruby
        end
      end

    end
  end
end