An ability to access PubSubHub from outside Flet app (flet-dev#3446)

* An ability to access PubSubHub from outside Flet app

Close flet-dev#3445

* Fix self.__pubsubhubs_lock

* Use "or" instead of "if-else"

sdk/python/packages/flet/src/flet/fastapi/flet_app.py

@@ -33,9 +33,6 @@
 DEFAULT_FLET_SESSION_TIMEOUT = 3600
 DEFAULT_FLET_OAUTH_STATE_TIMEOUT = 600
 
-_pubsubhubs_lock = asyncio.Lock()
-_pubsubhubs = {}
-
 
 class FletApp(LocalConnection):
     def __init__(
@@ -98,13 +95,9 @@ async def handle(self, websocket: WebSocket):
             else ""
         )
 
-        async with _pubsubhubs_lock:
-            psh = _pubsubhubs.get(self.__session_handler, None)
-            if psh is None:
-                psh = PubSubHub(loop=self.__loop, executor=app_manager.executor)
-                _pubsubhubs[self.__session_handler] = psh
-            self.pubsubhub = psh
-
+        self.pubsubhub = app_manager.get_pubsubhub(
+            self.__session_handler, loop=self.__loop
+        )
         self.page_url = str(websocket.url).rsplit("/", 1)[0]
         self.page_name = websocket.url.path.rsplit("/", 1)[0].lstrip("/")
 

sdk/python/packages/flet/src/flet/fastapi/flet_app_manager.py

@@ -12,6 +12,7 @@
 from flet_core.connection import Connection
 from flet_core.locks import NopeLock
 from flet_core.page import Page
+from flet_core.pubsub.pubsub_hub import PubSubHub
 from flet_core.utils.concurrency_utils import is_pyodide
 
 logger = logging.getLogger(flet_fastapi.__name__)
@@ -31,11 +32,26 @@ def __init__(self):
         self.__evict_oauth_states_task = None
         self.__temp_dirs = {}
         self.__executor = ThreadPoolExecutor(thread_name_prefix="flet_fastapi")
+        self.__pubsubhubs_lock = threading.Lock() if not is_pyodide() else NopeLock()
+        self.__pubsubhubs = {}
 
     @property
     def executor(self):
         return self.__executor
 
+    def get_pubsubhub(
+        self, session_handler, loop: Optional[asyncio.AbstractEventLoop] = None
+    ):
+        with self.__pubsubhubs_lock:
+            psh = self.__pubsubhubs.get(session_handler, None)
+            if psh is None:
+                psh = PubSubHub(
+                    loop=loop or asyncio.get_running_loop(),
+                    executor=self.__executor,
+                )
+                self.__pubsubhubs[session_handler] = psh
+            return psh
+
     async def start(self):
         """
         Background task evicting expired app data. Must be called at FastAPI application startup.