Config

Summary

Config helps you easily manage environment specific settings in an easy and usable manner

Features

• simple YAML config files
• config files support ERB
• config files support inheritance
• access config information via convenient object member notation

Compatibility

• Rails 3.0
• Padrino
• Sinatra

For older versions of Rails and other Ruby apps, use AppConfig.

Installing on Rails 3

Add this to your Gemfile:

gem "config"

Installing on Padrino

Add this to your Gemfile:

gem "config"

in your app.rb, you'll also want to register Config

register Config

Installing on Sinatra

Add this to your Gemfile:

gem "config"

in your app, you'll need to register RailsConfig. You'll also need to give it a root so it can find the config files.

set :root, File.dirname(__FILE__)
register Config

It's also possible to initialize it manually within your configure block if you want to just give it some yml paths to load from.

Config.sources("/path/to/yaml1", "/path/to/yaml2", ...)

Customizing Config

config/config.yml
config/environments/development.yml
config/environments/production.yml
config/environments/test.yml

Accessing the Config object

After installing this plugin, the Config object will be available globally. Entries are accessed via object member notation:

Config.my_config_entry

Nested entries are supported:

Config.my_section.some_entry

If you have set a different constant name for the object in the initializer file, use that instead.

Common config file

Config entries are compiled from:

config/config.yml
config/environments/#{environment}.yml
config/settings.yml
config/settings/#{environment}.yml

Settings defined in files that are lower in the list override settings higher.

Reloading settings

You can reload the Config object at any time by running Config.reload!.

Environment specific config files

You can have environment specific config files. Environment specific config entries take precedence over common config entries.

Example development environment config file:

#{Config.root}/config/environments/development.yml

Example production environment config file:

#{Config.root}/config/environments/production.yml

Adding sources at Runtime

You can add new YAML config files at runtime. Just use:

Config.add_source!("/path/to/source.yml")
Config.reload!

This will use the given source.yml file and use its settings to overwrite any previous ones.

One thing I like to do for my Rails projects is provide a local.yml config file that is .gitignored (so its independent per developer). Then I create a new initializer in config/initializers/add_local_config.rb with the contents

Config.add_source!("#{Config.root}/config/environments/local.yml")
Config.reload!

Embedded Ruby (ERB)

Embedded Ruby is allowed in the configuration files. See examples below.

Accessing Configuration Settings

Consider the two following config files.

{Config.root}/config/config.yml:

size: 1
server: google.com

{Config.root}/config/environments/development.yml:

size: 2
computed: <%= 1 + 2 + 3 %>
section:
  size: 3
  servers: [ {name: yahoo.com}, {name: amazon.com} ]

Notice that the environment specific config entries overwrite the common entries.

Config.size   # => 2
Config.server # => google.com

Notice the embedded Ruby.

Config.computed # => 6

Notice that object member notation is maintained even in nested entries.

Config.section.size # => 3

Notice array notation and object member notation is maintained.

Config.section.servers[0].name # => yahoo.com
Config.section.servers[1].name # => amazon.com

Authors

• Jacques Crocker
• Fred Wu
• Inherited from AppConfig by Christopher J. Bottaro