Fix modifying config structure

griptape/config/base_structure_config.py

@@ -39,11 +39,8 @@ class BaseStructureConfig(BaseConfig, ABC):
     text_to_speech_driver: BaseTextToSpeechDriver = field(kw_only=True, metadata={"serializable": True})
     audio_transcription_driver: BaseAudioTranscriptionDriver = field(kw_only=True, metadata={"serializable": True})
 
-    _structure: Optional[Structure] = field(default=None, kw_only=True, alias="structure")
-
-    @property
-    def structure(self) -> Optional[Structure]:
-        return self._structure
+    _structure: Structure = field(default=None, kw_only=True, alias="structure")
+    _event_listener: Optional[EventListener] = field(default=None, kw_only=True, alias="event_listener")
 
     @property
     def drivers(self) -> list:
@@ -58,14 +55,26 @@ def drivers(self) -> list:
             self.audio_transcription_driver,
         ]
 
+    @property
+    def structure(self) -> Optional[Structure]:
+        return self._structure
+
     @structure.setter
     def structure(self, structure: Structure) -> None:
-        self._structure = structure
+        if structure != self.structure:
+            event_publisher_drivers = [
+                driver for driver in self.drivers if driver is not None and isinstance(driver, EventPublisherMixin)
+            ]
 
-        event_listener = EventListener(self.structure.publish_event)
-        for driver in self.drivers:
-            if driver is not None and isinstance(driver, EventPublisherMixin):
-                driver.add_event_listener(event_listener)
+            for driver in event_publisher_drivers:
+                if self._event_listener is not None:
+                    driver.remove_event_listener(self._event_listener)
+
+            self._event_listener = EventListener(structure.publish_event)
+            for driver in event_publisher_drivers:
+                driver.add_event_listener(self._event_listener)
+
+        self._structure = structure
 
     def merge_config(self, config: dict) -> BaseStructureConfig:
         base_config = self.to_dict()

griptape/mixins/event_publisher_mixin.py

@@ -28,8 +28,6 @@ def add_event_listener(self, event_listener: EventListener) -> EventListener:
     def remove_event_listener(self, event_listener: EventListener) -> None:
         if event_listener in self.event_listeners:
             self.event_listeners.remove(event_listener)
-        else:
-            raise ValueError("Event Listener not found.")
 
     def publish_event(self, event: BaseEvent, *, flush: bool = False) -> None:
         for event_listener in self.event_listeners:

tests/unit/config/test_structure_config.py

@@ -1,6 +1,7 @@
 import pytest
 
 from griptape.config import StructureConfig
+from griptape.structures import Agent
 
 
 class TestStructureConfig:
@@ -60,3 +61,37 @@ def test_dot_update(self, config):
         config.prompt_driver.max_tokens = 10
 
         assert config.prompt_driver.max_tokens == 10
+
+    def test_drivers(self, config):
+        assert config.drivers == [
+            config.prompt_driver,
+            config.image_generation_driver,
+            config.image_query_driver,
+            config.embedding_driver,
+            config.vector_store_driver,
+            config.conversation_memory_driver,
+            config.text_to_speech_driver,
+            config.audio_transcription_driver,
+        ]
+
+    def test_structure(self, config):
+        structure_1 = Agent(
+            config=config,
+        )
+
+        assert config.structure == structure_1
+        assert config._event_listener is not None
+        for driver in config.drivers:
+            if driver is not None:
+                assert config._event_listener in driver.event_listeners
+                assert len(driver.event_listeners) == 1
+
+        structure_2 = Agent(
+            config=config,
+        )
+        assert config.structure == structure_2
+        assert config._event_listener is not None
+        for driver in config.drivers:
+            if driver is not None:
+                assert config._event_listener in driver.event_listeners
+                assert len(driver.event_listeners) == 1