feat(bookmarking): Use version info when un/serializing ui.Chat() messages (#1954)

Author: schloerke

CHANGELOG.md

@@ -13,7 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   * To enable bookmarking in Express mode, set `shiny.express.app_opts(bookmark_store=)` during the app's initial construction.
   * To enable bookmarking in Core mode, set `shiny.App(bookmark_store=)` when constructing the `app` object.
 
-* Added a new `.enable_bookmarking(client)` method to `ui.Chat()`. This method will attach bookmark hooks to save and restore the chat's messages and client state. (#1951)
+* Added a new `.enable_bookmarking(client)` method to `ui.Chat()`. This method will attach bookmark hooks to save and restore the chat's messages and client state. (#1951, #1954)
 
 * Both `ui.Chat()` and `ui.MarkdownStream()` now support the inclusion of Shiny UI elements inside of messages. This allows for gathering input from the user (e.g., `ui.input_select()`), displaying of rich output (e.g., `render.DataGrid()`), and more. (#1868)
 

shiny/ui/_chat_bookmark.py

@@ -72,7 +72,10 @@ def get_chatlas_state(
     async def get_state() -> Jsonifiable:
 
         turns: list[Turn[Any]] = client.get_turns()
-        return [turn.model_dump(mode="json") for turn in turns]
+        return {
+            "version": 1,
+            "turns": [turn.model_dump(mode="json") for turn in turns],
+        }
 
     return get_state
 
@@ -84,12 +87,26 @@ def set_chatlas_state(
 
     assert isinstance(client, Chat)
 
+    # TODO-future: Use pydantic model for validation
+    # instead of manual validation
     async def set_state(value: Jsonifiable) -> None:
 
-        if not isinstance(value, list):
-            raise ValueError("Chatlas bookmark value was not a list of objects")
+        if not isinstance(value, dict):
+            raise ValueError("Chatlas bookmark value was not a dictionary")
 
-        turns: list[Turn[Any]] = [Turn.model_validate(turn_obj) for turn_obj in value]
+        version = value.get("version")
+        if version != 1:
+            raise ValueError(f"Unsupported Chatlas bookmark version: {version}")
+        turns_arr = value.get("turns")
+
+        if not isinstance(turns_arr, list):
+            raise ValueError(
+                "Chatlas bookmark value was not a list of chat message information"
+            )
+
+        turns: list[Turn[Any]] = [
+            Turn.model_validate(turn_obj) for turn_obj in turns_arr
+        ]
         client.set_turns(turns)  # pyright: ignore[reportUnknownMemberType]
 
     return set_state