This is my own implementation of a REALLY simple configuration library, and when I say simple I mean it ! Most of the library available out there are far too complicated.

I decided to extract this code in a proper gem when I got tired of copying it over and over in my projects.

This gem is tested against these ruby by travis-ci.org:

• mri 1.9.2
• mri 1.8.7

My requirements for a config parser are:

• check that each line typed in the yaml file match a valid parameter I spent far too much time debugging application loading just because activerecord or any other gem did not warned me that a key was unknown (like "size" instead of "pool_size", you get the idea).
  What I expect is to have some return, taise an error, throw me a brick, do something damn !

• have a useable syntax to read the values

• something minimal which can be extended as needed (look at the source to really figure out how small this library is, there may even be more text in this README ! )

And honestly that's all, I don't want or need 100 different allowed formats with complex cases handled, so now that we are clear let's see how this thing works.

You have this yaml file:

logger:
  level: debug
  output: /tmp/file.log

app:
  data_path: /tmp
  
  server:
    port: 9000
    address: 127.0.0.1

Here is how you would use it:

require 'bundler/setup'
require 'dead_simple_conf'

module ConfigLoader
  class ServerConfig < DeadSimpleConf::ConfigBlock
    attr_accessor :port, :address
  end

  class AppConfig < DeadSimpleConf::ConfigBlock
    attr_accessor :data_path
    sub_section :server, ServerConfig
  
  end

  class LoggerConfig < DeadSimpleConf::ConfigBlock
    attr_accessor :level, :output
  end

  class MyConfig < DeadSimpleConf::ConfigBlock
    sub_section :app, AppConfig
    sub_section :logger, LoggerConfig  
  end
  
  def self.load(path)
    raw_data = YAML.load_file(path)
    MyConfig.new(raw_data)
  end
end

conf = ConfigLoader.load("conf.yml")
puts "conf.app.data_path    : #{conf.app.data_path}"
puts "conf.app.server.port  : #{conf.app.server.port}"

You can see both files in the examples folder.

Since I am only using standard class with getter and setters you should be able to extend it without much trouble, one one the thing which comes in mind is to use activemodel validation to validate incoming entries.