Application Configuration Class

class AppConfig
  # Loads a YAML configuration file from RAILS_ROOT/config/. The default file
  # it looks for is 'application.yml', although if this doesn't match your
  # application, you can pass in an alternative value as an argument 
  # to AppConfig.load.
  # After the file has been loaded, any inline ERB is evaluated and unserialized
  # into a hash. For each key-value pair in the hash, class getter and setter methods
  # are defined i.e., AppConfig.key => "value" 
  # This allows you to store your application configuration information e.g., API keys and 
  # authentication credentials in a convenient manner, external to your application source
  #
  # application.yml example
  #
  # :defaults: &defaults
  #  :app_name: Platform
  #  :app_domain: dev.example.com
  #  :admin_email: admin@example.com
  # :development:
  #  <<: *defaults
  # :test:
  #  <<: *defaults
  # :production:
  #  <<: *defaults
  #  :app_domain: example.com
  #
  # For example will result in AppConfig.app_domain => "dev.example.com"
  # when Rails.env == :development 
  #
  
  class << self
    def load(file='application.yml')
      configuration_file = File.join Rails.root, 'config', file
      File.open(configuration_file) do |configuration|
        configuration = ERB.new(configuration.read).result
        configuration = YAML.load(configuration)[Rails.env.to_sym]
        configuration.each do |key, value|
          cattr_accessor key
          send "#{key}=", value
        end
      end if File.exists? configuration_file
    end
  end
end
AppConfig.load