Improve support for stateless live components

Stop storing mock state objects in Redis

Author: imankulov

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## UNRELEASED
+
+- Improved support for stateless live components. They don't store mock state objects in Redis anymore.
+
 ## 1.8.0 (2023-12-18)
 
 - Added helper method StateAddress.with_component_id() to create a StateAddress with the same session ID, but a different component ID.

livecomponents/component.py

@@ -45,6 +45,33 @@ def get_command(self, command_name: str) -> Callable:
             )
         return command_func
 
+    def get_state(
+        self, state_manager: StateManager, state_addr: StateAddress
+    ) -> State | None:
+        """Get the state of this component."""
+        return state_manager.get_component_state(state_addr)
+
+    def get_or_create_state(
+        self,
+        state_manager: StateManager,
+        state_addr: StateAddress,
+        request: HttpRequest,
+        component_kwargs: dict[str, Any],
+    ) -> State:
+        """Internal function to get or create the state of this component.
+
+        We used it to override the function for the stateless component
+        where we don't need to store the state in Redis.
+        """
+        return state_manager.get_or_create_component_state(
+            request,
+            state_addr,
+            self.init_state,
+            self.update_state,
+            self.outer_context,
+            component_kwargs,
+        )
+
     def get_context_data(
         self,
         own_id: str = DEFAULT_OWN_ID,
@@ -67,15 +94,9 @@ def get_context_data(
             component_id=component_id,
         )
         state_manager = get_state_manager()
-        state = state_manager.get_or_create_component_state(
-            request,
-            state_addr,
-            self.init_state,
-            self.update_state,
-            self.outer_context,
-            component_kwargs,
+        state = self.get_or_create_state(
+            state_manager, state_addr, request, component_kwargs
         )
-
         extra_context_request: ExtraContextRequest[State] = ExtraContextRequest(
             request=request,
             state=state,
@@ -170,6 +191,20 @@ class StatelessLiveComponent(LiveComponent[StatelessModel]):
     extra_context_request contains the state_manager and state_addr.
     """
 
+    def get_state(
+        self, state_manager: StateManager, state_addr: StateAddress
+    ) -> StatelessModel | None:
+        return StatelessModel()
+
+    def get_or_create_state(
+        self,
+        state_manager: StateManager,
+        state_addr: StateAddress,
+        request: HttpRequest,
+        component_kwargs: dict[str, Any],
+    ) -> StatelessModel:
+        return StatelessModel()
+
     def init_state(self, context: InitStateContext) -> StatelessModel:
         return StatelessModel()
 

livecomponents/manager/manager.py

@@ -200,7 +200,9 @@ def call_component_command(
         component_cls = self.get_component_class(state_addr.get_component_name())
         component_instance = component_cls()
 
-        state = self.get_component_state(state_addr)
+        # Delegate fetching the state to the component instance because it may
+        # want to decide not to fetch the state from Redis.
+        state = component_instance.get_state(self, state_addr)
         if state is None:
             raise ValueError(f"Component state not found: {state_addr}")