module ModelAttribute

# File lib/model_attribute.rb, line 9
def self.extended(base)
  base.send(:include, InstanceMethods)
  base.instance_variable_set('@attribute_names',    [])
  base.instance_variable_set('@attribute_types',    {})
  base.instance_variable_set('@attribute_defaults', {})
end

# File lib/model_attribute.rb, line 16
  def attribute(name, type, opts = {})
    name = name.to_sym
    type = type.to_sym
    raise UnsupportedTypeError.new(type) unless SUPPORTED_TYPES.include?(type)

    @attribute_names          << name
    @attribute_types[name]    = type
    @attribute_defaults[name] = opts[:default] if opts.key?(:default)

    self.class_eval(<<-CODE, __FILE__, __LINE__ + 1)
      def #{name}=(value)
        write_attribute(#{name.inspect}, value, #{type.inspect})
      end

      def #{name}
        read_attribute(#{name.inspect})
      end

      def #{name}_changed?
        !!changes[#{name.inspect}]
      end
    CODE

    if type == :boolean
      self.class_eval(<<-CODE, __FILE__, __LINE__ + 1)
        def #{name}?
          !!read_attribute(#{name.inspect})
        end
      CODE
    end
  end

# File lib/model_attribute.rb, line 52
def attribute_defaults
  @attribute_defaults
end

# File lib/model_attribute.rb, line 48
def attributes
  @attribute_names
end