Add filter_by kwarg to serialize for ChatFeed

examples/reference/chat/ChatFeed.ipynb

@@ -604,6 +604,30 @@
  ")"
  ]
  },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "The messages can be filtered by using a custom `filter_by` function."
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": null,
+ "metadata": {},
+ "outputs": [],
+ "source": [
+ "def filter_by_reactions(messages):\n",
+ " return [message for message in messages if \"favorite\" in message.reactions]\n",
+ "\n",
+ "\n",
+ "chat_feed.send(\n",
+ " pn.chat.ChatMessage(\"I'm a message with a reaction!\", reactions=[\"favorite\"])\n",
+ ")\n",
+ "\n",
+ "chat_feed.serialize(filter_by=filter_by_reactions)"
+ ]
+ },
  {
  "cell_type": "markdown",
  "metadata": {},

panel/chat/feed.py

@@ -659,6 +659,7 @@ def clear(self) -> List[Any]:
 
  def _serialize_for_transformers(
  self,
+ messages: List[ChatMessage],
  role_names: Dict[str, str | List[str]] | None = None,
  default_role: str | None = "assistant",
  custom_serializer: Callable = None
@@ -681,8 +682,8 @@ def _serialize_for_transformers(
  for name in names:
  names_role[name.lower()] = role
 
- messages = []
- for message in self._chat_log.objects:
+ serialized_messages = []
+ for message in messages:
 
  lowercase_name = message.user.lower()
  if lowercase_name not in names_role and not default_role:
@@ -703,11 +704,12 @@ def _serialize_for_transformers(
  else:
  content = str(message)
 
- messages.append({"role": role, "content": content})
- return messages
+ serialized_messages.append({"role": role, "content": content})
+ return serialized_messages
 
  def serialize(
  self,
+ filter_by: Callable | None = None,
  format: Literal["transformers"] = "transformers",
  custom_serializer: Callable | None = None,
  **serialize_kwargs
@@ -720,10 +722,13 @@ def serialize(
  format : str
  The format to export the chat log as; currently only
  supports "transformers".
+ filter_by : callable
+ A function to filter the chat log by.
+ The function must accept and return a list of ChatMessage objects.
  custom_serializer : callable
  A custom function to format the ChatMessage's object. The function must
- accept one positional argument. If not provided,
- uses the serialize method on ChatMessage.
+ accept one positional argument, the ChatMessage object, and return a string.
+ If not provided, uses the serialize method on ChatMessage.
  **serialize_kwargs
  Additional keyword arguments to use for the specified format.
 
@@ -742,9 +747,13 @@ def serialize(
  -------
  The chat log serialized in the specified format.
  """
+ messages = self._chat_log.objects.copy()
+ if filter_by is not None:
+ messages = filter_by(messages)
+
  if format == "transformers":
  return self._serialize_for_transformers(
- custom_serializer=custom_serializer, **serialize_kwargs
+ messages, custom_serializer=custom_serializer, **serialize_kwargs
  )
  raise NotImplementedError(f"Format {format!r} is not supported.")
 

panel/chat/interface.py

@@ -23,7 +23,7 @@
 from ..widgets.button import Button
 from ..widgets.input import FileInput, TextInput
 from .feed import CallbackState, ChatFeed
-from .message import _FileInputMessage
+from .message import ChatMessage, _FileInputMessage
 
 
 @dataclass
@@ -543,6 +543,7 @@ def active(self, index: int) -> None:
 
  def _serialize_for_transformers(
  self,
+ messages: List[ChatMessage],
  role_names: Dict[str, str | List[str]] | None = None,
  default_role: str | None = "assistant",
  custom_serializer: Callable = None
@@ -552,6 +553,8 @@ def _serialize_for_transformers(
 
  Arguments
  ---------
+ messages : list(ChatMessage)
+ A list of ChatMessage objects to serialize.
  role_names : dict(str, str | list(str)) | None
  A dictionary mapping the role to the ChatMessage's user name.
  Defaults to `{"user": [self.user], "assistant": [self.callback_user]}`
@@ -563,8 +566,8 @@ def _serialize_for_transformers(
  If this is set to None, raises a ValueError if the user name is not found.
  custom_serializer : callable
  A custom function to format the ChatMessage's object. The function must
- accept one positional argument and return a string. If not provided,
- uses the serialize method on ChatMessage.
+ accept one positional argument, the ChatMessage object, and return a string.
+ If not provided, uses the serialize method on ChatMessage.
 
  Returns
  -------
@@ -575,7 +578,7 @@ def _serialize_for_transformers(
  "user": [self.user],
  "assistant": [self.callback_user],
  }
- return super()._serialize_for_transformers(role_names, default_role, custom_serializer)
+ return super()._serialize_for_transformers(messages, role_names, default_role, custom_serializer)
 
  @param.depends("_callback_state", watch=True)
  async def _update_input_disabled(self):

panel/tests/chat/test_feed.py

@@ -799,6 +799,16 @@ def custom_serializer(obj):
  with pytest.raises(ValueError, match="must return a string"):
  chat_feed.serialize(custom_serializer=custom_serializer)
 
+ def test_serialize_filter_by(self, chat_feed):
+ def filter_by_reactions(messages):
+ return [obj for obj in messages if "favorite" in obj.reactions]
+
+ chat_feed.send(ChatMessage("no"))
+ chat_feed.send(ChatMessage("yes", reactions=["favorite"]))
+ filtered = chat_feed.serialize(filter_by=filter_by_reactions)
+ assert len(filtered) == 1
+ assert filtered[0]["content"] == "yes"
+
 
 @pytest.mark.xdist_group("chat")
 class TestChatFeedSerializeBase: