Forms with Dynamic `required_slots` and slot Mappings in RC02

I wonder if the form described in this youtube tutorial is no longer compatible in Rasa 3.0.

I had this form that would add a slot if a name appeared that we believe is spelled incorrectly.

import yaml 
import pathlib 
from typing import Text, List, Any, Dict, Optional

from rasa_sdk import Tracker, FormValidationAction
from rasa_sdk.executor import CollectingDispatcher
from rasa_sdk.types import DomainDict

names = pathlib.Path("data/names.txt").read_text().split("\n")


class ValidateNameForm(FormValidationAction):
    def name(self) -> Text:
        return "validate_name_form"
    
    async def required_slots(
        self,
        slots_mapped_in_domain: List[Text],
        dispatcher: "CollectingDispatcher",
        tracker: "Tracker",
        domain: "DomainDict",
    ) -> Optional[List[Text]]:
        first_name = tracker.slots.get("first_name")
        if first_name is not None:
            if first_name not in names:
                return ["name_spelled_correctly"] + slots_mapped_in_domain
        return slots_mapped_in_domain

    async def extract_name_spelled_correctly(
        self, dispatcher: CollectingDispatcher, tracker: Tracker, domain: Dict
    ) -> Dict[Text, Any]:
        intent = tracker.get_intent_of_latest_message()
        return {"name_spelled_correctly": intent == "affirm"}

The reasoning here is that I would only ask about the spelling of the name if there was a reason to ask for it. That’s why the user isn’t bothered with extra questions. That’s why the slot was dynamically added here. Is such a pattern possible now that we have predefined slot mappings? It feels like I cannot use this dynamic trick anymore.

[ancalita]

Is this intent misclassification due to wrong training data / wrong config and has nothing to do with slot mappings?

The nlu training data in the repo indeed doesn’t have an intent defined + examples for when a name is given in an user utterance, so yes that could be a problem, however I haven’t followed that route especially that I remembered Akela saying that not all utterances containing information given to the bot have their own intents which is why from_text mapping gets used most often.

this still seems like behavior that’s different than in Rasa 2.x

Yes, action_extract_slots does not have the same extraction behaviour as forms in 2.x, because there’s no asking of slots in the default action, it runs through all slots and their mappings to check if any mapping is applicable with information gathered from latest UserUttered.

we may want to warn folks in the migration guide

I’ll have a think of how I’ll phrase this, maybe as a caution note to double-check behaviour when FormValidationAction is used and then link it to the default action page, I’ll see if that section may also need improving? Could you please submit a tiny docs issue for this @koaning ?

[ancalita]

Yup, I’ve added in the PR for slot mappings update (right at the bottom of the migration guide), not yet merged: https://github.com/RasaHQ/rasa/pull/10011/files