snippet.rb

require "rubygems"
require "json"

class Schema
  attr_accessor :hsh
  def initialize(h={})
    @hsh = {}
    case h
    when Hash
      h.each {|k,v| self[k] = v}
    when String        
      JSON.parse(h).each {|k,v| self[k.to_sym] = v}
    end
  end

  def [](k)
    hsh[k]
  end
  
  def []=(k,v)
    if v.is_a?(Hash)
      hsh[k.to_sym] = self.class.new(v)
    else
      hsh[k.to_sym] = v
    end      
  end

  def to_hash
    @hsh
  end
  
  def save!
    ::File.open("#{Default.base_config_directory}/#{Default.properties_hash_filename}", "w") {|f| f << self.to_json }
  end
  
  def method_missing(sym, *args, &block)
    if @hsh.has_key?(sym.to_sym)
      @hsh.fetch(sym)
    elsif @hsh.has_key?(sym.to_s)
      @hsh.fetch(sym.to_s)
    else
      @hsh.send(sym, *args, &block)
    end
  end
end

class Instance
  attr_reader :ip, :name
  def initialize(ip, name)
    @ip = ip
    @name = name
  end
  def to_s
    "#{@ip}\t#{@name}"
  end
end

a = Instance.new("10.0.1.1", "node1")
b = Instance.new("10.0.1.2", "node2")
c = Instance.new("10.0.1.3", "node3")

hsh = {:instances => [a,b,c]}

j = hsh.to_json

s = Schema.new(j)
p s.instances[0].split("\t") # ["10.0.1.1", "node1"]