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390792a Nov 16, 2018
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@Ghostvv @tmbo @akelad
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# -*- coding: utf-8 -*-
from typing import Dict, Text, Any, List, Union
from rasa_core_sdk import ActionExecutionRejection
from rasa_core_sdk import Tracker
from rasa_core_sdk.events import SlotSet
from rasa_core_sdk.executor import CollectingDispatcher
from rasa_core_sdk.forms import FormAction, REQUESTED_SLOT
class RestaurantForm(FormAction):
"""Example of a custom form action"""
def name(self):
# type: () -> Text
"""Unique identifier of the form"""
return "restaurant_form"
@staticmethod
def required_slots(tracker: Tracker) -> List[Text]:
"""A list of required slots that the form has to fill"""
return ["cuisine", "num_people", "outdoor_seating",
"preferences", "feedback"]
def slot_mappings(self):
# type: () -> Dict[Text: Union[Dict, List[Dict]]]
"""A dictionary to map required slots to
- an extracted entity
- intent: value pairs
- a whole message
or a list of them, where a first match will be picked"""
return {"cuisine": self.from_entity(entity="cuisine",
not_intent="chitchat"),
"num_people": [self.from_entity(entity="num_people",
intent=["inform",
"request_restaurant"]),
self.from_entity(entity="number")],
"outdoor_seating": [self.from_entity(entity="seating"),
self.from_intent(intent='affirm',
value=True),
self.from_intent(intent='deny',
value=False)],
"preferences": [self.from_intent(intent='deny',
value="no additional "
"preferences"),
self.from_text(not_intent="affirm")],
"feedback": [self.from_entity(entity="feedback"),
self.from_text()]}
@staticmethod
def cuisine_db():
# type: () -> List[Text]
"""Database of supported cuisines"""
return ["caribbean",
"chinese",
"french",
"greek",
"indian",
"italian",
"mexican"]
@staticmethod
def is_int(string: Text) -> bool:
"""Check if a string is an integer"""
try:
int(string)
return True
except ValueError:
return False
def validate(self,
dispatcher: CollectingDispatcher,
tracker: Tracker,
domain: Dict[Text, Any]) -> List[Dict]:
"""Validate extracted requested slot
else reject the execution of the form action
"""
# extract other slots that were not requested
# but set by corresponding entity
slot_values = self.extract_other_slots(dispatcher, tracker, domain)
# extract requested slot
slot_to_fill = tracker.get_slot(REQUESTED_SLOT)
if slot_to_fill:
slot_values.update(self.extract_requested_slot(dispatcher,
tracker, domain))
if not slot_values:
# reject form action execution
# if some slot was requested but nothing was extracted
# it will allow other policies to predict another action
raise ActionExecutionRejection(self.name(),
"Failed to validate slot {0} "
"with action {1}"
"".format(slot_to_fill,
self.name()))
# we'll check when validation failed in order
# to add appropriate utterances
for slot, value in slot_values.items():
if slot == 'cuisine':
if value.lower() not in self.cuisine_db():
dispatcher.utter_template('utter_wrong_cuisine', tracker)
# validation failed, set slot to None
slot_values[slot] = None
elif slot == 'num_people':
if not self.is_int(value) or int(value) <= 0:
dispatcher.utter_template('utter_wrong_num_people',
tracker)
# validation failed, set slot to None
slot_values[slot] = None
elif slot == 'outdoor_seating':
if isinstance(value, str):
if 'out' in value:
# convert "out..." to True
slot_values[slot] = True
elif 'in' in value:
# convert "in..." to False
slot_values[slot] = False
else:
dispatcher.utter_template('utter_wrong_outdoor_seating',
tracker)
# validation failed, set slot to None
slot_values[slot] = None
# validation succeed, set the slots values to the extracted values
return [SlotSet(slot, value) for slot, value in slot_values.items()]
def submit(self,
dispatcher: CollectingDispatcher,
tracker: Tracker,
domain: Dict[Text, Any]) -> List[Dict]:
"""Define what the form has to do
after all required slots are filled"""
# utter submit template
dispatcher.utter_template('utter_submit', tracker)
return []