Dumping hidden fields from nested params hash

hidden_fields_from_params.rb

  def hidden_fields_from_params(hash, prefix = "")
    hash.map do |hash_key, hash_value|
      if hash_value.is_a?(Hash)
        hidden_fields_from_params(hash_value, "#{prefix}[#{hash_key}]")
      else
        hidden_field_tag("#{prefix}[#{hash_key}]", hash_value)
      end
    end.join("\n").html_safe
  end