Cancel initiated slot correction - [ENG 414]

docs/docs/llms/flow-policy.mdx

@@ -170,6 +170,67 @@ prior input. The `FlowPolicy` depends on another component, like the
 and set the corresponding slots. Based on this, the `FlowPolicy` initiates the
 correction flow.
 
+### Cancelling an initiated correction
+
+Users have the option to cancel a correction initiated by them by adjusting the default
+ flow for pattern correction. The provided example demonstrates how to modify the 
+ default flow effectively. The confirm_correction question can be used to confirm if 
+ the user wants to accept the correction that was initiated. A custom action is 
+ used to set the values of the slot before correction.
+
+````yaml title="flows.yml"
+flows:
+  pattern_correction:
+    description: A meta flow that should be started to correct a previous user input.
+
+    steps:
+      - id: "0"
+        question: confirm_correction
+        next:
+          - if: confirm_correction
+            then: "1"
+          - else: "2"
+      - id: "1"
+        action: utter_corrected_previous_input
+      - id: "2"
+        action: action_cancel_correction
+        next: "3"
+      - id: "3"
+        action: utter_not_corrected_previous_input
+```
+
+```python
+from typing import Any, Dict
+from rasa_sdk import Action, Tracker
+from rasa_sdk.events import SlotSet
+from rasa_sdk.executor import CollectingDispatcher
+
+
+class CancelCorrectionTemplate(Action):
+
+    def name(self) -> str:
+        return "action_cancel_correction"
+
+    def run(self, dispatcher: CollectingDispatcher,
+            tracker: Tracker, domain: Dict[str, Any]):
+        events = []
+        CORRECTED_SLOTS_SLOT = "rasa_corrected_slots"
+        corrected_slots = tracker.get_slot(CORRECTED_SLOTS_SLOT)
+        if corrected_slots and tracker.latest_message.intent["name"] == "deny":
+            for corrected_slot in corrected_slots:
+                found_first_event = False
+                for event in reversed(tracker.events):
+                    if isinstance(event, SlotSet) and event.key == corrected_slot:
+                        if not found_first_event:
+                            found_first_event = True
+                        else:
+                            events.append(SlotSet(event.key, event.value))
+                            break
+        events.append(SlotSet(CORRECTED_SLOTS_SLOT, None))
+        return events
+
+```
+
 ## Configuration
 
 No additional configuration is required for the FlowPolicy beyond what's already

rasa/core/policies/default_flows.yml

@@ -4,26 +4,11 @@ responses:
     - text: Let's continue with the topic {rasa_previous_flow}.
       metadata: 
         rephrase: True
-
-  utter_ask_confirm_correction:
-    - text: "Do you want to update your information?"
-      buttons:
-        - payload: yes
-          title: Yes
-        - payload: no
-          title: No, please keep the previous information
-      metadata: 
-        rephrase: True
 
   utter_corrected_previous_input:
     - text: "Ok, I corrected the previous input."
       metadata: 
         rephrase: True
-
-  utter_not_corrected_previous_input:
-    - text: "Ok, I did not correct the previous input."
-      metadata: 
-        rephrase: True
 
   utter_flow_cancelled_rasa:
     - text: Okay, stopping the flow {rasa_cancelled_flow}.
@@ -36,12 +21,6 @@ responses:
   utter_internal_error_rasa:
     - text: Sorry, I'm having trouble understanding you right now. Please try again later.
 
-slots:
-  confirm_correction:
-    type: bool
-    mappings:
-      - type: custom
-
 flows:  
   pattern_continue_interrupted:
     description: A meta flow that should be started to continue an interrupted flow. 
@@ -55,19 +34,7 @@ flows:
 
     steps:
       - id: "0"
-        question: confirm_correction
-        next:
-          - if: confirm_correction
-            then: "1"
-          - else: "2"
-      - id: "1"
         action: utter_corrected_previous_input
-      - id: "2"
-        set_slots:
-          - rasa_corrected_slots: None
-        next: "3"
-      - id: "3"
-        action: utter_not_corrected_previous_input
 
   pattern_cancel_flow:
     description: A meta flow that's started when a flow is cancelled.

rasa/core/policies/flow_policy.py

@@ -695,17 +695,12 @@ def _run_step(
                     and previous_flow_step
                     and current_frame.frame_type == StackFrameType.CORRECTION
                 ):
-                    # TODO: we need to figure out how to actually
-                    #    "undo" the changed slots
                     corrected_slots = tracker.get_slot(CORRECTED_SLOTS_SLOT)
                     if corrected_slots:
                         self._correct_flow_position(
                             corrected_slots, previous_flow_step, previous_flow, tracker
                         )
-                    else:
-                        # TODO: we need to figure out how to actually "undo" the
-                        #    changed slots
-                        pass
+
             return ActionPrediction(None, 0.0, events=events)
         else:
             raise FlowException(f"Unknown flow step type {type(step)}")