AppConf

Simplest YAML Backed Application Wide Configuration (AppConfig)

• Load from YAML file(s)
• Add additional key/value pairs in code
• Use dot or bracket notation
• AppConf.to_hash outputs a hash map of AppConf key/values

Installation

gem install app_conf

Example

config.yml

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

other.yml

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

Code:

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

Syntax

Load multiple files at once:

AppConf.load(*filenames)

Or individually:

AppConf.load(filename1)
AppConf.load(filename2)

Use either method calls or hash syntax:

AppConf.fullname
AppConf[:fullname]
AppConf['fullname']

Infinitely nested keys:

AppConf.multiple.nested.keys

Override existing values:

AppConf.loaded.from.yaml = 'can override'
AppConf['loaded']['from']['yaml'] = 'can override'

Set new values:

AppConf.non_existing_value = 'can set'

Clear entire tree:

AppConf.clear

Returns nil for non-existent keys:

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

Use from_hash to create non-existent nodes:

AppConf.from_hash({...})

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

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

Other stuff

• Works with Ruby 1.9.2
• No gem dependencies
• Fully tested with MiniTest::Spec
• Packaged as a Gem on RubyGems.org

Why

• 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 :-)

Known Issues

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

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