Real World Rails

rails.rb

# app/services/calculation_service.rb
class CalculationService
  def initialize(repository)
    @repository = repository
  end
 
  def calculate(operation, x, y)
    result = StatelessCalculator.send operation, x, y
    @repository.save_calculation operation, x, y, result
    result
  end
end
 
# app/controllers/calculation.rb
def create
  h = ActiveSupport::JSON.decode(request.body)
  @result = MyApp::Services.calculation.calculate h["operation"], h["x"], h["y"]
  render :calculation_view
end