use module/global variable instead of ClassVar

reflex/app.py

@@ -46,7 +46,7 @@
     Default404Page,
     wait_for_client_redirect,
 )
-from reflex.components.core.upload import Upload
+from reflex.components.core.upload import upload_component_used
 from reflex.config import get_config
 from reflex.event import Event, EventHandler, EventSpec
 from reflex.middleware import HydrateMiddleware, Middleware
@@ -245,7 +245,7 @@ def add_default_endpoints(self):
         self.api.get(str(constants.Endpoint.PING))(ping)
 
         # To upload files.
-        if Upload._used:
+        if upload_component_used:
             self.api.post(str(constants.Endpoint.UPLOAD))(upload(self))
 
     def add_cors(self):

reflex/components/core/upload.py

@@ -1,7 +1,7 @@
 """A file upload component."""
 from __future__ import annotations
 
-from typing import Any, ClassVar, Dict, List, Optional, Union
+from typing import Any, Dict, List, Optional, Union
 
 from reflex import constants
 from reflex.components.chakra.forms.input import Input
@@ -99,12 +99,13 @@ class UploadFilesProvider(Component):
     tag = "UploadFilesProvider"
 
 
+# Indicate at least one Upload component is used, to enable the /_upload endpoint.
+upload_component_used: bool = False
+
+
 class Upload(Component):
     """A file upload component."""
 
-    # Indicate at least one Upload component is used, to enable the /_upload endpoint.
-    _used: ClassVar[bool] = False
-
     library = "react-dropzone@14.2.3"
 
     tag = "ReactDropzone"
@@ -151,7 +152,8 @@ def create(cls, *children, **props) -> Component:
         Returns:
             The upload component.
         """
-        cls._used = True
+        global upload_component_used
+        upload_component_used = True
 
         # get only upload component props
         supported_props = cls.get_props()

reflex/components/core/upload.pyi

@@ -7,7 +7,7 @@ from typing import Any, Dict, Literal, Optional, Union, overload
 from reflex.vars import Var, BaseVar, ComputedVar
 from reflex.event import EventChain, EventHandler, EventSpec
 from reflex.style import Style
-from typing import Any, ClassVar, Dict, List, Optional, Union
+from typing import Any, Dict, List, Optional, Union
 from reflex import constants
 from reflex.components.chakra.forms.input import Input
 from reflex.components.chakra.layout.box import Box
@@ -107,13 +107,14 @@ class UploadFilesProvider(Component):
         """
         ...
 
+upload_component_used: bool
+
 class Upload(Component):
     @overload
     @classmethod
     def create(  # type: ignore
         cls,
         *children,
-        _used: Optional[ClassVar[bool]] = None,
         accept: Optional[
             Union[Var[Optional[Dict[str, List]]], Optional[Dict[str, List]]]
         ] = None,
@@ -185,7 +186,6 @@ class Upload(Component):
 
         Args:
             *children: The children of the component.
-            _used: Indicate at least one Upload component is used, to enable the /_upload endpoint.
             accept: The list of accepted file types. This should be a dictionary of MIME types as keys and array of file formats as  values.  supported MIME types: https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types
             disabled: Whether the dropzone is disabled.
             max_files: The maximum number of files that can be uploaded.