私有服务对象方法 (Ruby + Rails)

Question

我有一个 PaymentManager 服务：

/payment_manager/
  - online_payment_creator.rb
  - manual_payment_creator.rb
  - payment_splitter.rb

3 项服务的代码：

module PaymentManager
  class ManualPaymentCreator < ApplicationService
    def call
      # do stuff in transaction
      PaymentSplitter.call(a, b, c)
    end
  end
end

module PaymentManager
  class OnlinePaymentCreator < ApplicationService
    # do stuff in transaction
    PaymentSplitter.call(a2, b2, c2)
  end
end

module PaymentManager
  class PaymentSplitter < ApplicationService
    def call(x, y, z)
      # do very dangerous stuff
    end
  end
end

因此，PaymentSplitter 本质上是将付款拆分到多张发票中，并且必须仅在其他 2 项服务中的任何一项中完成，但绝不能调用它自己的（来自控制器或控制台等）。

我通常会在 ManualPaymentCreator 中创建一个 private 方法，但是因为这两个服务都需要它，所以我不知道该怎么做，因为我不能使用简单的私有实例没有重复的方法。

Answer 1

也许您正在寻找继承和受保护的方法

class Foo < ApplicationService
  def public_method
  end

  protected
    #everything after here is private to this class and its descendants
    def some_method_to_be_shared_with_descendants
      #I am only accessible from this class and from descendants of this class

      ...
    end

  private
    #Everything after here is private to this class only

    def some_private_methods_that_are_only_accessible_from_this_class
    end
    ...
end

然后子孙类这样

class Bar < Foo
  def do_something
    # can access protected methods from Foo class here as native methods
    some_res = some_method_to_be_shared_here
    # do something with some_res
  end
end

所以你应该从 PaymentSplitter 继承你的其他 2 类并将共享方法设置为受保护

Answer 2

也许包含在模块中的私有 class 可能会更好，例如。

module PaymentSplitting
  def self.included(klass)
    raise 'Error' unless klass.in?([ManualPaymentCreator, OnlinePaymentCreator])
  end

  class PaymentSplitter
  end
  private_constant :PaymentSplitter
end

这应该允许您在包含 PaymentSplitting 的任何 class 中自由引用 PaymentSplitter，并且您只能在 ManualPaymentCreator 或 OnlinePaymentCreator。引用 PaymentSplitting::PaymentSplitter 将抛出 NameError: private constant 异常。

私有服务对象方法 (Ruby + Rails)

Private service object methods (Ruby + Rails)

ruby

ruby-on-rails

ruby-on-rails-6