Merge pull request #26 from Amirali-Shirkh/feature/url-rewriting-for-images

feat: support for image url text replacements in BotfrontTemplatedNaturalLanguageGenerator and GraphQLNaturalLanguageGenerator

Author: pheel

rasa_addons/core/nlg/bftemplate.py

@@ -1,7 +1,7 @@
 import copy
 import logging
 from collections import defaultdict
-
+from rasa_addons.core.nlg.nlg_helper import rewrite_url
 from rasa.core.trackers import DialogueStateTracker
 from typing import Text, Any, Dict, Optional, List
 
@@ -14,6 +14,8 @@
 class BotfrontTemplatedNaturalLanguageGenerator(NaturalLanguageGenerator):
     def __init__(self, **kwargs) -> None:
         domain = kwargs.get("domain")
+        templated_endpoint = kwargs.get("endpoint_config")
+        self.url_substitution_pattern = templated_endpoint.kwargs.get('url_substitutions') or []
         self.templates = domain.templates if domain else []
 
     def _templates_for_utter_action(self, utter_action, output_channel, **kwargs):
@@ -85,11 +87,13 @@ async def generate(
             fallback_language=fallback_language,
         )
         if "language" in message: del message["language"]
+        rewrite_url(message, self.url_substitution_pattern)
         metadata = message.pop("metadata", {}) or {}
         for key in metadata: message[key] = metadata[key]
 
         return message
 
+
     def generate_from_slots(
         self,
         template_name: Text,

rasa_addons/core/nlg/constants.py

@@ -0,0 +1,10 @@
+from enum import Enum
+
+class NlgEnum(Enum):
+    """A class to represent constants for enum values for nlg classes."""
+
+    IMAGE = "image"
+    IMAGE_URL = "image_url"
+    ELEMENTS = "elements"
+    PATTERN = "pattern"
+    REPLACEMENT = "replacement"

rasa_addons/core/nlg/graphql.py

@@ -1,6 +1,6 @@
 import logging
 from typing import Text, Any, Dict, Optional, List
-
+from rasa_addons.core.nlg.nlg_helper import rewrite_url
 from rasa.core.constants import DEFAULT_REQUEST_TIMEOUT
 from rasa.core.nlg.generator import NaturalLanguageGenerator
 from rasa.core.trackers import DialogueStateTracker, EventVerbosity
@@ -100,13 +100,13 @@ def nlg_request_format(
         "channel": {"name": output_channel},
     }
 
-
 class GraphQLNaturalLanguageGenerator(NaturalLanguageGenerator):
     """Like Rasa's CallbackNLG, but queries Botfront's GraphQL endpoint"""
 
     def __init__(self, **kwargs) -> None:
         endpoint_config = kwargs.get("endpoint_config")
         self.nlg_endpoint = endpoint_config
+        self.url_substitution_pattern = endpoint_config.kwargs.get('url_substitutions') or []
 
     async def generate(
         self,
@@ -152,6 +152,7 @@ async def generate(
                         ", ".join([e.get("message") for e in response.get("errors")])
                     )
                 response = response.get("data", {}).get("getResponse", {})
+                rewrite_url(response, self.url_substitution_pattern)
                 if "customText" in response:
                     response["text"] = response.pop("customText")
                 if "customImage" in response:

rasa_addons/core/nlg/nlg_helper.py

@@ -0,0 +1,23 @@
+import re
+from rasa_addons.core.nlg.constants import NlgEnum
+
+def rewrite_url(message: dict, url_substitution_pattern: list):
+    """Rewrite image url with the pattern found in endpoint."""
+    
+    if url_substitution_pattern:
+        if NlgEnum.IMAGE.value in message.keys():
+            substitute(message, NlgEnum.IMAGE.value, url_substitution_pattern)
+        elif NlgEnum.ELEMENTS.value in message.keys():
+            for element in message[NlgEnum.ELEMENTS.value]:
+                substitute(element, NlgEnum.IMAGE_URL.value, url_substitution_pattern)
+
+def substitute(message: dict, key: str, url_substitution_pattern: list):
+    """Substitute rewritten url."""
+
+    url = message[key]
+    for item in url_substitution_pattern:
+        substitute = re.sub(item.get(NlgEnum.PATTERN.value), item.get(NlgEnum.REPLACEMENT.value), message[key])
+        if substitute != url:
+            message[key] = substitute
+            return
+    return