Application level configuration.
* simple YAML config files * config files support ERB * config files support inheritance * access config information via convenient object member notation
You simply write a configuration file in YAML. Notice you can use ERB.
config.yml
aws: access_key: 123ABC secret_key: ABC123 now: <%= Time.now %> servers: [ {name: example1.com}, {name: example2.com} ]
Then somewhere in your code, you create a global constant from the config file. Then access the config data via object member notation.
code
::AppConfig = ApplicationConfiguration.new("config.yml") AppConfig.aws.access_key # => "123ABC" AppConfig.aws.secret_key # => "ABC123" AppConfig.now # => Tue May 05 21:55:15 -0500 2009 AppConfig.servers[0].name # => "example1.com"
You can have a second config file that is recursively merged with the first config file.
base.yml
app_name: MyCoolApp domain: dev.mycoolapp.com
production.yml
domain: www.mycoolapp.com
code
::AppConfig = ApplicationConfiguration.new("base.yml", "production.yml") AppConfig.app_name # => "MyCoolApp" AppConfig.domain # => "www.mycoolapp.com"
You just need to create an initializer that looks something like this.
require 'app_config' ::AppConfig = ApplicationConfiguration.new(RAILS_ROOT+"/config/app_config.yml", RAILS_ROOT+"/config/environments/#{RAILS_ENV}.yml")
If you installed this as a Rails plugin instead of a gem, that code is already run for you in the plugin’s init.rb.
Alternatively to splitting out your environments into separate files, you can just have a single file which defines the application configuration for all environments (much like how databases.yml works). Note if you do this, nested configurations will not be recursively merged. See example below.
app_config.yml
defaults: &defaults one: won two: too nested: foo: foo bar: bar development: <<: *defaults two: new nested: foo: bar
code
RAILS_ENV # => "development" ::AppConfig = ApplicationConfiguration.new("app_config.yml") AppConfig.use_environment!(RAILS_ENV) AppConfig.one # => "won" AppConfig.two # => "new" AppConfig.nested.foo # => "bar" AppConfig.nested.bar # raises NoMethodError because nested configurations are not recursively merged
Christopher J. Bottaro