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Version: Master/Unreleased

rasa.core.actions.forms

FormAction Objects

class FormAction(LoopAction)

Action which implements and executes the form logic.

__init__

def __init__(form_name: Text, action_endpoint: Optional[EndpointConfig]) -> None

Creates a FormAction.

Arguments:

  • form_name - Name of the form.
  • action_endpoint - Endpoint to execute custom actions.

name

def name() -> Text

Return the form name.

required_slots

def required_slots(domain: Domain) -> List[Text]

A list of required slots that the form has to fill.

Returns:

A list of slot names.

from_entity

def from_entity(entity: Text, intent: Optional[Union[Text, List[Text]]] = None, not_intent: Optional[Union[Text, List[Text]]] = None, role: Optional[Text] = None, group: Optional[Text] = None) -> Dict[Text, Any]

A dictionary for slot mapping to extract slot value.

From:

  • an extracted entity
  • conditioned on
    • intent if it is not None
    • not_intent if it is not None, meaning user intent should not be this intent
    • role if it is not None
    • group if it is not None

get_mappings_for_slot

def get_mappings_for_slot(slot_to_fill: Text, domain: Domain) -> List[Dict[Text, Any]]

Get mappings for requested slot.

If None, map requested slot to an entity with the same name

get_ignored_intents

def get_ignored_intents(domain: Domain) -> List[Text]

Returns a list of ignored intents.

Arguments:

  • domain - The current model domain.

Returns:

The value/s found in ignored_intents parameter in the domain.yml (under forms).

intent_is_desired

def intent_is_desired(requested_slot_mapping: Dict[Text, Any], tracker: "DialogueStateTracker", domain: Domain) -> bool

Check whether user intent matches intent conditions.

entity_is_desired

def entity_is_desired(slot_mapping: Dict[Text, Any], slot: Text, entity_type_of_slot_to_fill: Optional[Text], tracker: DialogueStateTracker, domain: Domain) -> bool

Check whether slot should be filled by an entity in the input or not.

Arguments:

  • slot_mapping - Slot mapping.
  • slot - The slot to be filled.
  • entity_type_of_slot_to_fill - Entity type of slot to fill.
  • tracker - The tracker.
  • domain - The domain.

Returns:

True, if slot should be filled, false otherwise.

get_entity_value_for_slot

@staticmethod
def get_entity_value_for_slot(name: Text, tracker: "DialogueStateTracker", slot_to_be_filled: Text, role: Optional[Text] = None, group: Optional[Text] = None) -> Any

Extract entities for given name and optional role and group.

Arguments:

  • name - entity type (name) of interest
  • tracker - the tracker
  • slot_to_be_filled - Slot which is supposed to be filled by this entity.
  • role - optional entity role of interest
  • group - optional entity group of interest

Returns:

Value of entity.

extract_other_slots

def extract_other_slots(tracker: DialogueStateTracker, domain: Domain) -> Dict[Text, Any]

Extract the values of the other slots if they are set by corresponding entities from the user input else return None.

get_slot_to_fill

def get_slot_to_fill(tracker: "DialogueStateTracker") -> Optional[str]

Gets the name of the slot which should be filled next.

When switching to another form, the requested slot setting is still from the previous form and must be ignored.

Returns:

The slot name or None

extract_requested_slot

def extract_requested_slot(tracker: "DialogueStateTracker", domain: Domain, slot_to_fill: Text) -> Dict[Text, Any]

Extract the value of requested slot from a user input else return None.

Arguments:

  • tracker - a DialogueStateTracker instance
  • domain - the current domain
  • slot_to_fill - the name of the slot to fill

Returns:

a dictionary with one key being the name of the slot to fill and its value being the slot value, or an empty dictionary if no slot value was found.

validate_slots

async def validate_slots(slot_candidates: Dict[Text, Any], tracker: "DialogueStateTracker", domain: Domain, output_channel: OutputChannel, nlg: NaturalLanguageGenerator) -> List[Union[SlotSet, Event]]

Validate the extracted slots.

If a custom action is available for validating the slots, we call it to validate them. Otherwise there is no validation.

Arguments:

  • slot_candidates - Extracted slots which are candidates to fill the slots required by the form.
  • tracker - The current conversation tracker.
  • domain - The current model domain.
  • output_channel - The output channel which can be used to send messages to the user.
  • nlg - NaturalLanguageGenerator to use for response generation.

Returns:

The validation events including potential bot messages and SlotSet events for the validated slots.

validate

async def validate(tracker: "DialogueStateTracker", domain: Domain, output_channel: OutputChannel, nlg: NaturalLanguageGenerator) -> List[Union[SlotSet, Event]]

Extract and validate value of requested slot.

If nothing was extracted reject execution of the form action. Subclass this method to add custom validation and rejection logic

request_next_slot

async def request_next_slot(tracker: "DialogueStateTracker", domain: Domain, output_channel: OutputChannel, nlg: NaturalLanguageGenerator, events_so_far: List[Event]) -> List[Union[SlotSet, Event]]

Request the next slot and response if needed, else return None.

activate

async def activate(output_channel: "OutputChannel", nlg: "NaturalLanguageGenerator", tracker: "DialogueStateTracker", domain: "Domain") -> List[Event]

Activate form if the form is called for the first time.

If activating, validate any required slots that were filled before form activation and return Form event with the name of the form, as well as any SlotSet events from validation of pre-filled slots.

Arguments:

  • output_channel - The output channel which can be used to send messages to the user.
  • nlg - NaturalLanguageGenerator to use for response generation.
  • tracker - Current conversation tracker of the user.
  • domain - Current model domain.

Returns:

Events from the activation.