Contents

module HasDefaults
  module ActiveRecordExt

    module ClassMethods

      def has_defaults(attrs)
        raise "Hash expected; #{attrs.class} given." unless attrs.is_a?(Hash)

        include InstanceMethods

        unless respond_to?(:has_defaults_options)
          class_inheritable_hash :has_defaults_options
        end

        self.has_defaults_options ||= {}
        self.has_defaults_options.merge!(attrs)

        if Rails.version < '3'
          # ActiveRecord only calls after_initialize callbacks only if is
          # explicit defined in a class. We should however only define that
          # callback if a default has been set, as it really slow downs Rails.
          unless method_defined?(:after_initialize)
            define_method(:after_initialize) {}
          end
        end

        after_initialize :set_default_attributes
      end

    end

    module InstanceMethods

      def default_for(name)
        self.class.has_defaults_options[name.to_sym]
      end

      private

      def set_default_attributes
        if new_record?
          self.class.has_defaults_options.each do |name, value|
            if send(name).nil?
              value = instance_eval(&value) if value.respond_to?(:call)
              send("#{name}=", value)
            end
          end
        end
      end

    end

  end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
has_defaults-0.3.1	lib/has_defaults/active_record_ext.rb
has_defaults-0.3.0	lib/has_defaults/active_record_ext.rb