gistfile1.rbx

require "rubygems"
require "json"

tohle_je_json_z_fajlu = <<HEREDOC
{
  "disp": "nejaky text",
  "platforma": [
    {
      "ido": 1,
      "jmeno": "prvni",
      "priorita": 3,
      "mountpoints": [1,3,4]
    },{
      "ido": 1,
      "jmeno": "druha",
      "priorita": 3,
      "mountpoints": [1,3,4]
    }
  ]
}
HEREDOC

o = JSON.parse(tohle_je_json_z_fajlu)
puts o.inspect

module PlatformyMixin

  def platforma # tento getter by mel byt autogenerovany
    self['platforma']
  end
  
  def jmena_platforem
    platforma.map{|o| o['jmeno'] }.sort!
  end
end

o.extend(PlatformyMixin)

puts o.jmena_platforem