我可以让 AASM 在事件失败时运行特定方法吗？

Question

有没有一种好的方法可以告诉 AASM，如果在处理任何 assm_event 时引发异常，我希望特定的代码块捕获该错误？

例如，目前我做了类似的事情

assm_state :state_1
assm_state :state_2, :before_enter => :validate_something
assm_state :failed


assm_event :something_risky do
  transition :from => :state_1, :to => :state_2
end

assm_event :fail do
  transition :from => [:state_1, :state_2], :to => :failed
end

def validate_something
  begin
    something_that_might_raise_error
  rescue
    self.record_error
    self.fail
  end
end

，我更愿意做的是

assm_state :state_1
assm_state :state_2, :before_enter => :validate_something
assm_state :failed


assm_event :something_risky, :on_exception => :log_failure do
  transition :from => :state_1, :to => :state_2
end

assm_event :fail do
  transition :from => [:state_1, :state_2], :to => :failed
end

def validate_something
    something_that_might_raise_exception
end

def log_failure
  self.record_error
  self.fail
end

如果 something_that_might_raise_exception 确实引发异常，则调用 log_failure 。理想情况下，我想避免更改 AASM，这样如果将来需要升级它，我就可以安全了

Answer 1

如果您使用 SimpleStateMachine 您可以执行以下操作：

  def something_risky
    something_that_might_raise_error
  rescue
    record_error
    raise #reraise the error
  end
  event :something_risky, :state1 => :state2,
                          RuntimeError => :failed

Answer 2

我也遇到了这个问题。我有两件事要做。

1. 请遵循此博客中的建议 http://degenportnoy.blogspot.com /2009/11/event-callbacks-in-aasm.html。
2. 即使您正在开发模式下工作，也需要重新启动应用程序。