querying json data

json_query.rb

require 'json'

data1 = JSON.load('{"status": "fail", "messages": ["Out of capacity"]}')
data2 = JSON.load('{"status": "success", "messages": [], "result": {"node": {"ip": "1.2.3.4", "description": "", "id": 974, "name": "VM#3"}}}')

def get_from_json(data, query)
  query.split('.').inject(data) do |memo, key|
    key = key.to_i if memo.is_a?(Array)
    memo.fetch(key)
  end
end

get_from_json(data1, 'messages.0')        # => "Out of capacity"
get_from_json(data2, 'result.node.ip')    # => "1.2.3.4"