Douglas F Shearer

There are a lot of Rails config options around, but despite this, I thought I’d share mine.

My design goals for this were:

1. Once the configuration was loaded, it would be stored in memory for the next time it was required.
2. Nice usage syntax, like config.authentication.password rather than the oft-used config[:authentication_password].
3. Zero dependencies outside what is already included in Rails.

config/app.yml

  # Rails Config.
  # Copyrighted(c) Douglas F Shearer 2009
  # Licensed under The MIT License.
  site:
    url: http://example.com

  authentication:
    username: bob@example.com
    password: myhackproofpassword

  flickr:
    api_key: d3c3576398a4876c920553b714bc177f
    username: flickrusername

  # Akismet.
  wordpress:
    api_key: 876c920553b7

config/initializers/config.rb

  # Rails Config Loader.
  # Copyrighted(c) Douglas F Shearer 2009
  # Licensed under The MIT License.
  module Config

    class ConfigStore

      # Takes a hash as an argument.
      # If this hash contains other hashes, these too will turned into
      # ConfigStore objects.
      def initialize(contents)
        @contents = contents

        @contents.each do |k, v|
          if v.is_a?(Hash)
            @contents[k] = self.class.new(v)
          end
        end

      end

      def method_missing(sym, *args)    
        @contents[sym.to_s] || super
      end

    end

    def config
      @@config ||= ConfigStore.new(YAML.load_file("#{RAILS_ROOT}/config/app.yml"))
    end
  end

  include Config

Usage

With both these files in place, we can now call the config from anywhere in our app:

  >> config.authentication.username
  => "bob@example.com"
  >> config.authentication.password
  => "myhackproofpassword"

I’ll probably add overrides for environment specific configuration in the future, but this covers most of my needs for now.