如何使用 Open/Closed 原则或策略模式重构此 ruby 代码

Question

如何使用 Open/Closed 原则或策略模式重构此 ruby 代码？我知道主要思想是 'software entities (classes, modules, functions, etc.) should be open for extension, but closed for modification' 但我如何在实践中使用它？

class PaymentService
  def initialize(payment, payment_type)
    @payment = payment
    @payment_type = payment_type
  end

  def process
    result = case payment_type
    when 'first'
      process_first
    when 'second'
      process_second
    end

    payment.save(result)
  end

  def process_first
    'process_first'
  end

  def process_second
    'process_second'
  end
end

Answer 1

在此示例中，您可以构建一个带有 class 的对象来处理付款，而不是传递 payment_type：

class FirstPayment
  def process
    'process_first'
  end
end

class SecondPayment
  def process
    'process_second'
  end
end

class PaymentService
  def initialize(payment, payment_strategy)
    @payment = payment
    @payment_strategy = payment_strategy
  end

  def process
    result = @payment_stategy.process
    payment.save(result)
  end
end

PaymentService.new(payment, FirstPayment.new)

因此，PaymentService 行为可以通过传递新策略（例如，ThirdPayment）来扩展，但是 class 不需要修改，如果更改了处理第一笔或第二笔付款的逻辑。

如何使用 Open/Closed 原则或策略模式重构此 ruby 代码

How can I refactor this ruby code using the Open/Closed principle or Strategy pattern

ruby

ruby-on-rails

strategy-pattern

open-closed-principle