mattr_accessor

Extends the module object with module and instance accessors for class attributes, just like the native attr* accessors for instance attributes.

module AppConfiguration
  mattr_accessor :google_api_key

  self.google_api_key = "123456789"
end

AppConfiguration.google_api_key # => "123456789"
AppConfiguration.google_api_key = "overriding the api key!"
AppConfiguration.google_api_key # => "overriding the api key!"

To opt out of the instance writer method, pass instance_writer: false. To opt out of the instance reader method, pass instance_reader: false. To opt out of both instance methods, pass instance_accessor: false.