utility methods for hashes

hash_utils.rb

class HashUtils
  # See also various flattening solutions at http://stackoverflow.com/questions/23521230/flattening-nested-hash-to-a-single-hash-with-ruby-rails
  def self.flatten_hash(param, prefix='')
    param.each_pair.reduce({}) do |a, (k, v)|
      v.is_a?(Hash) ? a.merge(flatten_hash(v, "#{prefix}#{k}.")) : a.merge("#{prefix}#{k}".to_sym => v)
    end
  end
end

class Hash
  def flatten(prefix)
    HashUtils.flatten_hash(self, prefix='')
  end
end