使用state_machine gem的嵌套状态机的ruby类

Question

all I am trying to implement state machine on ActiveRecord object https://github.com/pluginaweek/state_machine gem. But I would like to have nested state_machines. So far I have this simple state machine:

class Document < ActiveRecord::Base

  state_machine :initial => :new do
    before_transition :new => :processing, :do => :start_processing

    event :start_processing do
      transition :new => :upload_to
    end

    event :finish_processing do
      transition :processing => :ok
    end

    event :error_in_processing do
      transition :processing => :error
    end

    event :to_trash do
      transition :processing => :trash
    end
  end

But what I would like to do, is to have nested state machine which would start after transition to processing state. This nested state machine would have states such as, uploading_to_xxx, extracting_from_yyy, pending, verifying and so on. I could probably implement this using just one state machine, but I would prefer to use nested state machines. I can not find any samples on web. Does state_machine support this use case? Or if there is other gem could you point me to it? thanks

Answer 1

我想你可以通过工作流gem https://github.com/geekq/workflow来完成这个任务