YAML Backed Application Wide Configuration with a few extras

(AppConfig like)

• Supports nested key/values
• Loading and Saving of YAML files
• Add further key/value pairs in code
• Use dot or bracket notation
• AppConf#to_hash outputs a hash map of AppConf key/values
• AppConf#from_hash creates nested key/values from a hash

gem install app_conf

config.yml

---
fullname: Joe Bloggs
user:
  name: Joe

other.yml

---
user:
  address:
    street: 1 Some Road

Code:

$conf = AppConf.new

$conf.load('config.yml', 'other.yml')
$conf.fullname -> 'Joe Blogs'
$conf.user.name -> 'Joe'
$conf.user[:address]['street'] -> '1 Some Road'

Load multiple files at once:

$conf.load(*filenames)

Or individually:

$conf.load(filename1)
$conf.load(filename2)

Use either method calls or hash syntax:

$conf.fullname
$conf[:fullname]
$conf['fullname']

Infinitely nested keys:

$conf.multiple.nested.keys

Override existing values:

$conf.loaded.from.yaml = 'can override'
$conf['loaded']['from']['yaml'] = 'can override'

Set new values:

$conf.non_existing_value = 'can set'

Clear entire tree:

$conf.clear

Returns nil for non-existent keys:

$conf.non_existing -> nil
$conf.non_existing.name -> NoMethodError: undefined method 'name' for nil:NilClass

Use from_hash to create non-existent nodes:

$conf.from_hash({...})

Not dependent on Rails but easy to use with it. For example:

$conf.load('config.yml', "#{Rails.env}.yml")

• Works with Ruby 1.9.2 and 1.9.3
• No gem dependencies
• Fully tested with MiniTest::Spec
• Packaged as a Gem on RubyGems.org
• Less than 80 lines of code (not including tests)

• Because I wanted to write the simplest useful app config possible
• Others are either too simple or incomplete, lack documentation or aren't Gem installable
• Because I can :-)

Cannot assign values to unknown nested keys because they return nil (create the tree first):

$conf.from_hash({:non_existing => {:name => 'bla'}})