Purspose of restart ,UserUtteranceReverted and ConversationPaused?

Rasa Open Source
1

I found this code in Rasa demo project.rasa-demo/actions.py at master · RasaHQ/rasa-demo · GitHub

Could anybody explain the purpose of restart button ,UserUtteranceReverted() and ConversationPaused() in 2 way fall back.?

class ActionDefaultFallback(Action):
def name(self) -> Text:
    return "action_default_fallback"

def run(
    self,
    dispatcher: CollectingDispatcher,
    tracker: Tracker,
    domain: Dict[Text, Any],
) -> List["Event"]:

    # Fallback caused by TwoStageFallbackPolicy
    if (
        len(tracker.events) >= 4
        and tracker.events[-4].get("name") == "action_default_ask_affirmation"
    ):

        dispatcher.utter_template("utter_restart_with_button", tracker)

        return [SlotSet("feedback_value", "negative"), ConversationPaused()]

    # Fallback caused by Core
    else:
        dispatcher.utter_template("utter_default", tracker)
        return [UserUtteranceReverted()]
2

@erohmensing/@Tanja could you please help me with this?

3

UserUtteranceReverted() removes the previous user input from the tracker (i.e. it is being reverted). So this would could be used when the previous user intent has been classified incorrectly. So he/she can rephrase it. Not sure about the usage in this particular case.