v0.6.4 Pre-release thread

[masenf]

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

pip install 'reflex~=0.6.4a'

Schedule

2024-10-25 09:30 PDT: 0.6.4a1 pre-release published for testing
2024-10-28 17:10 PDT: 0.6.4a2 pre-release published
2024-10-29 13:09 PDT: 0.6.4a3 pre-release published
2024-10-29: Planned Public release of 0.6.4

Release Notes

Changes in 0.6.4a3

• add existing path subclass for env checks by @adhami3310 in add existing path subclass for env checks #4260
• port enum env var support from More env var cleanup #4248 by @benedikt-bartscher in port enum env var support from #4248 #4251

Changes in 0.6.4a2

• Handle props annotated as list/dict of EventHandler (Handle props annotated as list/dict of EventHandler #4257)

New Features

Make Var System Expandable

A new dispatch mechanism for converting python values into Var and LiteralVar subclasses. This allows component authors and downstream applications to better support custom frontend operations on Python values converted to Javascript values

See Example

This example allows for near drop-in support for working with SQLAlchemy DeclarativeBase models and will likely be included in a future release:

from collections.abc import Mapping, MutableSet, Sequence
from typing import TypeVar
import dataclasses
import sys

import reflex as rx
import sqlalchemy
import sqlalchemy.orm.exc
from sqlalchemy.orm import DeclarativeBase


class DeclarativeBaseVar(rx.vars.ObjectVar, python_types=DeclarativeBase):
    pass


@dataclasses.dataclass(
    eq=False,
    frozen=True,
    **{"slots": True} if sys.version_info >= (3, 10) else {},
)
class LiteralDeclarativeBaseVar(rx.vars.LiteralObjectVar, DeclarativeBaseVar):
    _var_value: DeclarativeBase | None = None


T = TypeVar("T")
K = TypeVar("K")
V = TypeVar("V")


@rx.serializer
def serialize_Sequence(s: Sequence[T] | MutableSet[T]) -> list[T]:
    return list(s)


@rx.serializer
def serialize_Mapping(m: Mapping[K, V]) -> dict[K, V]:
    return dict(m)


@rx.serializer
def serialize_DeclarativeBase(obj: DeclarativeBase) -> dict[str, str]:
    s = {}
    for attr in sqlalchemy.inspect(type(obj)).all_orm_descriptors.keys():
        try:
            s[attr] = getattr(obj, attr)
        except sqlalchemy.orm.exc.DetachedInstanceError:
            # This happens when the relationship was never loaded and the session is closed.
            continue
    return s

• make var system expandable by @adhami3310 in make var system expandable #4175

max-requests support to gunicorn (fixed memory leak)

This is a new configurable option in the rx.config but also now has default values.
gunicorn_max_requests - ( gunicorn / uvicorn )max requests per worker
Defaults value - 100
gunicorn_max_requests_jitter - (gunicorn only) variance in the max request limit. To prevent all workers restarting at same time
Defaults value - 25

What is max_requests?

max_requests is a the maximum number of requests a worker can serve before the manager will kill the worker and restart.

Why is this needed?

gunicorn workers don't release memory after a request. This can cause for a workers to hold on to more and more memory over time. Setting this flag means that after serving N requests the worker is killed, thus releasing the memory, and a new worker is spun up.

How to configure

rx.config(
    ...
     gunicorn_max_requests=50
    ...
)

Experimental Shiki Codeblock

rx._x.code_block(
"""
print("Original text")   # [!code --]
print("Replace original with this") # [!code ++]

name = "John Doe"  # [!code highlight]
""",
    language="python",
    theme="dracula",
    use_transformers=True,
    can_copy=True,
    show_line_numbers=True
)

• [ENG-3848][ENG-3861]Shiki Code block Experimental by @ElijahAhianyo in [ENG-3848][ENG-3861]Shiki Code block Experimental #4030

dotenv support added

To use this feature, you must install python-dotenv separately from reflex.

import reflex as rx

config = rx.Config(
    app_name="mycoolapp",
    env_file=".env",
)

• HOS-93: add support for .env file by @Kastier1 in HOS-93: add support for .env file #4219
• make python-dotenv optional by @Lendemor in make python-dotenv optional #4222

New rx.dynamic decorator

Unlike normal UI functions, this decorator allows UI code to directly access State instance values, Python-only APIs, and typical for and if statements.

See Example

We can implement a simple Reflex fiddle, that evaluates component strings into UI components and render them. This was previously difficult, as all UI had to compile into react code in the .web folder. This works by dynamically compiling a JavaScript module using in-window react.

import reflex as rx


class State(rx.State):
    component_str = "rx.button('login')"


@rx.dynamic
def evaluated_component(state: State):
    try:
        component = eval(
            state.component_str,
            {
                "rx": rx,
                "State": State,
            },
        )
    except Exception as e:
        return rx.text(f"Error: {e}")
    if not isinstance(component, rx.Component):
        return rx.text("Invalid component")
    return component


def index():
    return (
        rx.hstack(
            rx.text_area(
                value=State.component_str,
                on_change=State.set_component_str,
                height="100%",
                flex="1",
            ),
            rx.card(evaluated_component(), height="100%", flex="1"),
            height="100vh",
            padding="1rem",
            box_size="border-box",
        ),
    )

• implement rx dynamic by @adhami3310 in implement rx dynamic #4195

Improvements

Better Type Hinting for Built in Components

• add type hinting to error boundary by @adhami3310 in add type hinting to error boundary #4182
• add event types to suneditor by @adhami3310 in add event types to suneditor #4209
• Add type hinting to dataeditor events by @adhami3310 in Add type hinting to dataeditor events #4210
• Add on progress typing to react player by @adhami3310 in Add on progress typing to react player #4211
• add additional typing for calling events by @adhami3310 in add additional typing for calling events #4218

Other Improvements

• allow setting run mode via env, add helpers to determine it by @benedikt-bartscher in allow setting run mode via env, add helpers to determine it #4168
• Raise TypeError when ComputedVar.__init__ gets bad kwargs by @masenf in Raise TypeError when ComputedVar.__init__ gets bad kwargs #4199
• move all environment variables to the same place by @adhami3310 in move all environment variables to the same place #4192
• [ENG-3970] When normal pickle fails, try dill by @masenf in [ENG-3970] When normal pickle fails, try dill #4239

Bug Fixes

• use larger or equal for node version check by @adhami3310 in use larger or equal for node version check #4189
• check for none before returning which by @adhami3310 in check for none before returning which #4187
• fix and test bug in config env loading by @benedikt-bartscher in fix and test bug in config env loading #4205
• fix inverted alembic file check by @adhami3310 in fix inverted alembic file check #4238
• fix: async default setters break setvar by @benedikt-bartscher in fix: async default setters break setvar #4169
• Fix 'enter_key_submit=True' on 'rx.text_area' by carrying custom_code on debounce by @masenf in Fix 'enter_key_submit=True' on 'rx.text_area' by carrying custom_code on debounce #4142

Version Bumps

• upgrade node to latest lts by @adhami3310 in upgrade node to latest lts #4191
• versions bump before 0.6.4 by @Lendemor in versions bump before 0.6.4 #4208
• bump ruff to 0.7.0 by @Lendemor in bump ruff to 0.7.0 #4213

Other Changes

• pin AppHarness tests to ubuntu-22.04 runner by @masenf in pin AppHarness tests to ubuntu-22.04 runner #4173
• Remove demo command by @Alek99 in Remove demo command #4176
• move client storage classes to their own file by @Lendemor in move client storage classes to their own file #4216
• use $ syntax by @adhami3310 in use $ syntax #4237
• test for stateless apps by @Lendemor in test for stateless apps #3816

Full Changelog: v0.6.3.post1...release/reflex-0.6.4

[masenf]

0.6.4 is released!