reflex-dev/reflex v0.5.2 on GitHub

New Features

Lifespan Tasks

A lifespan task is either a coroutine which runs while the backend server is running and is cancelled when the server stops, or it can be an asynccontextmanager in which case it will run at server startup until yield is called, then it will resume as the server is shutting down. In either case, the task is started and stopped during hot reload.

Any keyword arguments passed to app.register_lifespan_task will be passed to the coroutine/contextmanager. If the coroutine takes a parameter called app, this will be an instance of the underlying FastAPI object.

Sample Code

import asyncio
from contextlib import asynccontextmanager


def fake_answer_to_everything_ml_model(x: float):
    return x * 42


ml_models = {}


@asynccontextmanager
async def setup_model(app: FastAPI):
    # Load the ML model
    ml_models["answer_to_everything"] = fake_answer_to_everything_ml_model
    yield
    # Clean up the ML models and release the resources
    ml_models.clear()


async def long_running_task(foo, bar):
    print(f"Starting {foo} {bar} task")
    some_api = SomeApi(foo)
    try:
        while True:
            updates = some_api.poll_for_updates()
            other_api.push_changes(updates, bar)
            await asyncio.sleep(5)  # add some polling delay to avoid running too often
    except asyncio.CancelledError:
        some_api.close()  # clean up the API if needed
        print("Task was stopped")


app = rx.App()
app.register_lifespan_task(setup_model)
app.register_lifespan_task(long_running_task, foo=42, bar=os.environ["BAR_PARAM"])

add support for lifespan tasks by @Lendemor in #3312

Improvements

Catch more errors in frontend/backend by @picklelo in #3346
Use twine environment variables if set by @ericwb in #3353
add style for orientation=vertical in tabs by @Lendemor in #3332
Added config for number of gunicorn workers by @Snaipergelka in #3351
feat: Optionally comparing fields in Var.contains, e.g. on rx.Base based types. by @abulvenz in #3375

Bug Fixes

fix rx.cond with ComputedVars and use union type by @benedikt-bartscher in #3336
do not check attribute type for var internals by @benedikt-bartscher in #3357
[REF-2915] ComponentState subclasses are always treated as mixin by @masenf in #3372
- Fix regression when subclassing a ComponentState subclass.
set config.deploy_url during AppHarness tests by @benedikt-bartscher in #3359
[REF-2878] Map fontFamily to fontFamily and --default-font-family by @masenf in #3380
url quote the str data passed to rx.download by @masenf in #3381

Readme Updates

update README to use 0.5.0 by @Lendemor in #3313
#3321: Update Chinese README.md by @seewindcn in #3350
Update Spanish README.md by @boterop in #3330
Update Korean README.md by @owlur in #3337

Other Changes

Add some minimal validation of pyproject.toml by @ericwb in #3339
Suppress runtime warnings by @picklelo in #3354

New Contributors

@owlur made their first contribution in #3337

Full Changelog: https://github.com/reflex-dev/reflex/compare/v0.5.1..v0.5.2