使用多态状态机进行跟踪

Question

我有这个多态模型。

class Note < ApplicationRecord

  belongs_to :notable, polymorphic: true, optional: false


  state_machine :status, initial: :pending do
    transition pending: :approved, on: %i[approve]
    transition pending: :cancelled, on: %i[cancel]
  end
end

和其他两个模型

class Invoice < ApplicationRecord

  has_many :notes, as: :notable, dependent: :destroy
end

class Person < ApplicationRecord

  has_many :notes, as: :notable, dependent: :destroy
end

如您所见，我将便笺以两种方式附加在其个人或发票上。并使用状态机场景是我只想在invoice中使用状态机？这可能吗。所以。如果我的notable_type是“发票”。我的状态为“待处理”，否则为“我的人状态：nil

Answer 1

正如我所看到的，您可以传递notable_type == Invoice是状态机过滤其他notable_type的条件

Answer 2

您可以参考AASM gem。https://github.com/aasm/aasm。这不仅可以帮助您在所有转换中添加防护方法，而且还可以在回调之前和之后。

您还可以添加AASM挂钩方法并在那里设置状态。例如：-

class Note < ApplicationRecord
  belongs_to :notable, polymorphic: true, optional: false
  include AASM
  aasm do
    state :pending
    state :approved
    state :cancelled
    event :approve do
      transitions from: :pending, to: :approved, before: some_method, after: some_method1
    end
    event :cancel do
      transitions from: :pending, to: :cancelled, before: some_method2, after: some_method3
    end
  end
    def aasm_ensure_initial_state
      if notable_type == "Invoice"
        self.aasm_state = :pending
      else
        self.aasm_state = nil
      end
    end
  end
end