Method emit_update

reflex/app.py:1676–1702

Emit an update to the client. Args: update: The state update to send. token: The client token (tab) associated with the event.

(self, update: StateUpdate, token: str)

        return None

    async def emit_update(self, update: StateUpdate, token: str) -> None:
        """Emit an update to the client.

        Args:
            update: The state update to send.
            token: The client token (tab) associated with the event.
        """
        socket_record = self._token_manager.token_to_socket.get(token)
        if (
            socket_record is None
            or socket_record.instance_id != self._token_manager.instance_id
        ):
            if isinstance(self._token_manager, RedisTokenManager):
                # The socket belongs to another instance of the app, send it to the lost and found.
                await self._token_manager.emit_lost_and_found(token, update)
            else:
                # If the socket record is None, we are not connected to a client. Prevent sending
                # updates to all clients.
                console.warn(
                    f"Attempting to send delta to disconnected client {token!r}"
                )
            return
        # Creating a task prevents the update from being blocked behind other coroutines.
        await asyncio.create_task(
            self.emit(str(constants.SocketEvent.EVENT), update, to=socket_record.sid),
            name=f"reflex_emit_event|{token}|{socket_record.sid}|{time.time()}",
        )

    async def on_event(self, sid: str, data: Any):
        """Event for receiving front-end websocket events.