ROR：Workflow gem：我想从数据库实现动态状态

我正在研究一个必须实现动态工作流的项目。

动态 ：我将工作流的状态存储在名为wf_steps的数据库表中，工作流gem必须从数据库为特定工作流创建states

为此，我试图使用工作流gem 。 您可以在gem的github-page中看到它如何初始化状态和相应的事件。

我的代码：

 class SpsWorkflow < ActiveRecord::Base belongs_to :user has_many :wf_steps include Workflow workflow do # binding.pry # read wf-states from the database # for now let event be same for all the states self.wf_steps.each do |step| state step.title.to_sym do event :assign, transitions_to: :assigning event :hire, transitions_to: :hiring event :not_hire, transitions_to: :not_hiring end end end end 

遇到的期望和问题：

我期望在下面的代码块中， self.wf_steps将返回我的SpsWorkflow的实例/集合。 但是当我在workflow方法的块中使用#时， self关键字返回# （我在代码中注释）

 # read wf-states from the database # for now let event be same for all the states self.wf_steps.each do |step| state step.title.to_sym do 

需要你的帮助，谢谢

编辑：我也尝试将实例存储在变量中，并使用块内的变量传递给workflow方法调用。

 class SpsWorkflow < ActiveRecord::Base include Workflow sps_instance = self 

但是我得到了类SpsWorkflow的实例

 SpsWorkflow(id: integer, workflow_state: string, assigned_to: integer, title: string, description: string, organization_id: integer, user_id: integer, created_at: datetime, updated_at: datetime) 

但我想要

  # 

Answer 1

你用过：

 workflow do self.something end 

self在此块的上下文中将引用WorkflowSpecification 。 如果您真的想要访问SpsWorkflow的实例， SpsWorkflow可能必须将其传递到块中或将其分配给另一个变量并在那里使用它。

Answer 2

我终于使用activerecord回调解决了它

 class SpsWorkflow < ActiveRecord::Base include Workflow after_initialize do sps_instance = self SpsWorkflow.workflow do # read wf-states as well as events from the database sps_instance.wf_steps.each do |step| state step.title.to_sym do event :assign, transitions_to: :step2 event :hire, transitions_to: :hire event :not_hire, transitions_to: :not_hiring end end end end belongs_to :user has_many :wf_steps end