Skip to content

feat: nullable exception handlers #5703

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 4 commits into
base: main
Choose a base branch
from
Open

feat: nullable exception handlers #5703

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
ff9323d
feat: nullable exception handlers
Aug 11, 2025
5e77d17
fix: fixed validation of handlers
Aug 11, 2025
20b467f
fix: pyright fixes
Aug 11, 2025
7ceac10
fix: use is not None
Aug 13, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
15 changes: 10 additions & 5 deletions reflex/app.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -422,14 +422,14 @@ class App(MiddlewareMixin, LifespanMixin):
_background_tasks: set[asyncio.Task] = dataclasses.field(default_factory=set)

# Frontend Error Handler Function
frontend_exception_handler: Callable[[Exception], None] = (
frontend_exception_handler: Callable[[Exception], None] | None = (
default_frontend_exception_handler
)

# Backend Error Handler Function
backend_exception_handler: Callable[
[Exception], EventSpec | list[EventSpec] | None
] = default_backend_exception_handler
backend_exception_handler: (
Callable[[Exception], EventSpec | list[EventSpec] | None] | None
) = default_backend_exception_handler

# Put the toast provider in the app wrap.
toaster: Component | None = dataclasses.field(default_factory=toast.provider)
Expand Down Expand Up @@ -1620,6 +1620,10 @@ def _validate_exception_handlers(self):
],
strict=True,
):
if handler_fn is None:
# If the handler is None, skip validation.
continue

if hasattr(handler_fn, "__name__"):
_fn_name = handler_fn.__name__
else:
Expand Down Expand Up @@ -1773,7 +1777,8 @@ async def process(
except Exception as ex:
telemetry.send_error(ex, context="backend")

app.backend_exception_handler(ex)
if app.backend_exception_handler is not None:
app.backend_exception_handler(ex)
raise


Expand Down
13 changes: 9 additions & 4 deletions reflex/state.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1880,8 +1880,12 @@ async def _process_event(
except Exception as ex:
telemetry.send_error(ex, context="backend")

app = prerequisites.get_and_validate_app().app

event_specs = (
prerequisites.get_and_validate_app().app.backend_exception_handler(ex)
app.backend_exception_handler(ex)
if app.backend_exception_handler
else None
)

yield await state._as_state_update(
Expand Down Expand Up @@ -2433,9 +2437,10 @@ def handle_frontend_exception(self, info: str, component_stack: str) -> None:
component_stack: The stack trace of the component where the exception occurred.

"""
prerequisites.get_and_validate_app().app.frontend_exception_handler(
Exception(info)
)
app = prerequisites.get_and_validate_app().app

if app.frontend_exception_handler is not None:
app.frontend_exception_handler(Exception(info))


class UpdateVarsInternalState(State):
Expand Down
Loading