如何在关注中定义state_machine？

Question

我试图将一些重复的逻辑分解为一个问题.部分重复逻辑是state_machine.

简化的Database,Site,SftpUser多包含,除其他外,这样的:

class Database < ActiveRecord::Base
  # ...
  state_machine :deploy_state, initial: :halted do
    state :pending
  end
end

我试图将此重构为一个问题:

module Deployable
  extend ActiveSupport::Concern

  included do
    state_machine :deploy_state, initial: :halted do
      state :pending
    end
  end
end

# Tested with:
class DeployableDouble < ActiveRecord::Base
  extend Deployable
end

describe DeployableDouble do
  let(:subject) { DeployableDouble.new }

  it "should have default state halted" do
    subject.deploy_state.must_equal "halted"
  end
end

但是,这不是在a state_machnine中实现a的正确方法concern,因为这会导致:NoMethodError: undefined method 'deploy_state' for <DeployableDouble:0xb9831f8>.这表明Double根本没有分配一个状态机.

included do实际上是实际上是正确的回调吗？它可能是一个问题state_machine,它需要一个ActiveRecord :: Base的子类吗？我得不到的东西？我很关注忧虑的概念.

Answer 1

好的.我感觉真的很蠢.不应该extend是具有模块的类,而是include该模块.明显.

# Tested with:
class DeployableDouble
  include Deployable
end

一旦写完你就会监督的其中一件事.此外,ActiveRecord::Base不需要扩展,因为state_machine只是普通的旧Ruby,适用于通用的Ruby对象.