test_ctrl.rb

  def create
    test = Test.new format_params(params)
    test.normalize_data

    if test.save
      render json: test
    else
      puts test.errors.messages
      render text: test.errors.messages
    end
  end
  
  private
  def format_params(params)
      # model interface: name, stamp_name, device_id, max_ref_coord, obs_count, serialized_data
      # api interface: test_id, stamp_id, device_id, max_x & max_y, obs_count, data OR data_string

      f_params = {} # a.k.a formatted_params
      f_params[:name] = CGI.unescape(params[:test_id]) if params[:test_id]
      f_params[:stamp_name] = CGI.unescape(params[:stamp_id]) if params[:stamp_id]
      f_params[:device_id] = params[:device_id].to_i if params[:device_id]
      max_x, max_y = params[:max_x].to_f, params[:max_y].to_f
      f_params[:max_ref_coord] = [max_x, max_y] if max_x and max_y
      f_params[:obs_count] = params[:obs_count].to_i if max_x and max_y

      if params[:data_string]
        f_params[:serialized_data] = JSON::parse(params[:data_string])
      else
        f_params[:serialized_data] = params[:data]
      end

      return f_params
    end