module ActiveAdmin::Settings::ClassMethods

def setting(name, default)
  default_settings[name] = default
  attr_writer name
  # Create an accessor that looks up the default value if none is set.
  define_method name do
    if instance_variable_defined? "@#{name}"
      instance_variable_get "@#{name}"
    else
      read_default_setting name.to_sym
    end
  end
  define_method "#{name}?" do
    value = public_send(name)
    if value.is_a? Array
      value.any?
    else
      value.present?
    end
  end
end