带有state_machine gem的Rails应用程序＆＃34;未定义的方法＆＃39; state_paths＆＃39; ...＆＃34;

Question

在Rails 3应用程序中，我有以下内容：

class Kase < ActiveRecord::Base
  state_machine :state, :initial => :lead do
    state :lead
    state :active
    state :completed

    event :reset_status do
      transition any => :lead
    end

    event :activate do
      transition any => :active
    end

    event :complete do
      transition any => :completed
    end
  end
end

文档（https://github.com/pluginaweek/state_machine）显示以下内容适用于我的情况：

vehicle.state_paths # => [[#<StateMachine::Transition ...], [#<StateMachine::Transition ...], ...]
vehicle.state_paths.to_states # => [:lead, :active, :completed]

但是，当我运行以下操作时出现错误：

@kase = Kase.first
@kase.state
  => "lead"
@kase.state_paths
  NoMethodError: undefined method `state_paths' for #<Kase:0x00000100d95ca0> ...

我正在尝试获取Kase所有可能状态的列表。我错过了什么？

Answer 1

state_paths在state_machine的已发布版本中不可用。本周将发布一个新版本，其中包括您尝试使用的功能。