use background task to cancel content deletion on handshake

nicegui/air.py

@@ -139,12 +139,12 @@ def _handle_handshake(data: Dict[str, Any]) -> bool:
             return True
 
         @self.relay.on('client_disconnect')
-        async def _handle_client_disconnect(data: Dict[str, Any]) -> None:
+        def _handle_client_disconnect(data: Dict[str, Any]) -> None:
             self.log.debug('client disconnected.')
             client_id = data['client_id']
             if client_id not in Client.instances:
                 return
-            await Client.instances[client_id].handle_disconnect()
+            Client.instances[client_id].handle_disconnect()
 
         @self.relay.on('connect')
         async def _handle_connect() -> None:

nicegui/client.py

@@ -60,6 +60,7 @@ def __init__(self, page: page, *, request: Optional[Request]) -> None:
         self.shared = request is None
         self.on_air = False
         self._num_connections = 0
+        self._delete_task: Optional[asyncio.Task] = None
         self._deleted = False
         self.tab_id: Optional[str] = None
 
@@ -236,6 +237,9 @@ def on_disconnect(self, handler: Union[Callable[..., Any], Awaitable]) -> None:
 
     def handle_handshake(self, next_message_id: Optional[int]) -> None:
         """Cancel pending disconnect task and invoke connect handlers."""
+        if self._delete_task:
+            self._delete_task.cancel()
+            self._delete_task = None
         self._num_connections += 1
         if next_message_id is not None:
             self.outbox.try_rewind(next_message_id)
@@ -245,16 +249,19 @@ def handle_handshake(self, next_message_id: Optional[int]) -> None:
         for t in core.app._connect_handlers:  # pylint: disable=protected-access
             self.safe_invoke(t)
 
-    async def handle_disconnect(self) -> None:
+    def handle_disconnect(self) -> None:
         """Wait for the browser to reconnect; invoke disconnect handlers if it doesn't."""
+        async def delete_content() -> None:
+            await asyncio.sleep(self.page.resolve_reconnect_timeout())
+            if self._num_connections == 0:
+                self.delete()
         self._num_connections -= 1
         for t in self.disconnect_handlers:
             self.safe_invoke(t)
         for t in core.app._disconnect_handlers:  # pylint: disable=protected-access
             self.safe_invoke(t)
-        await asyncio.sleep(self.page.resolve_reconnect_timeout())
-        if self._num_connections == 0 and not self.shared:
-            self.delete()
+        if not self.shared:
+            self._delete_task = background_tasks.create(delete_content())
 
     def handle_event(self, msg: Dict) -> None:
         """Forward an event to the corresponding element."""

nicegui/nicegui.py

@@ -178,13 +178,13 @@ async def _on_handshake(sid: str, data: Dict[str, Any]) -> bool:
 
 
 @sio.on('disconnect')
-async def _on_disconnect(sid: str) -> None:
+def _on_disconnect(sid: str) -> None:
     query_bytes: bytearray = sio.get_environ(sid)['asgi.scope']['query_string']
     query = urllib.parse.parse_qs(query_bytes.decode())
     client_id = query['client_id'][0]
     client = Client.instances.get(client_id)
     if client:
-        await client.handle_disconnect()
+        client.handle_disconnect()
 
 
 @sio.on('event')