v0.5.2 Pre-release Thread

[masenf]

Try out the Prerelease

Please report any problems you encounter in this discussion thread or as separate issues on reflex-dev/reflex.

pip install 'reflex~=0.5.2a'

Schedule

2024-05-26 14:35 PDT: 0.5.2a1 pre-release published for testing
2024-05-30 17:00 PDT: Public Release of 0.5.2

Release Notes

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 is 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 add support for lifespan tasks #3312

Improvements

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

Bug Fixes

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

Readme Updates

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

Other Changes

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

New Contributors

• @owlur made their first contribution in Update Korean README.md #3337

Full Changelog: https://github.com/reflex-dev/reflex/compare/v0.5.1..reflex-0.5.2

[masenf]

Release is published