Async support

[Ventura94]

it would be great if it had async support

[FeodorFitsner]

Like what part of the framework, could you please elaborate?

[Ventura94]

I say it for example, when we need in our app, to make several requests to an API, or we integrate with an asynchronous database, we can make better use of the time it takes for a response

[Ventura94]

In addition, we could take advantage of the ListView and other widgets such as flutter, which until it has the information to display, place the gif loader or temporary images

[keyiflerolsun]

i can use async like this;

Async Things

from aiohttp import ClientSession
from asyncio import new_event_loop, run
from atexit  import register as to_exit

class WeatherData:
    def __close_session(self):
        run(self.session.close())

    def __init__(self, city:str):
        self.session = ClientSession()
        to_exit(self.__close_session)

        self.__api_key = "2a7db0585e7541018229c17efb2efa94"
        self.city      = city

    async def get_data(self):
        async with self.session.get(
            url     = "https://api.weatherbit.io/v2.0/current/weather",
            params  = {
                "city" : self.city,
                "key"  : self.__api_key
            },
        ) as response:
            return await response.json()


async def get_weather(city:str):
    weather_api = WeatherData(city)
    data = (await weather_api.get_data())["data"][0]
    return f"{data['ob_time']} » [{data['country_code']}] {data['city_name']} - {data['weather']['description']}"

Flet Things

from flet      import app as flet
from flet.page import Page, ControlEvent
from flet      import (
    ElevatedButton, Text, TextField, icons, ProgressBar, ProgressRing, Row, Switch
)

def main_page(page:Page):
    page.title = "Async OpenWeather"
    page.horizontal_alignment = "center"

    def change_theme_func(_:ControlEvent):
        page.theme_mode    = "dark" if page.theme_mode == "light" else "light"
        change_theme.label = "Light" if page.theme_mode == "light" else "Dark"
        page.update()

    page.theme_mode = "dark"
    change_theme    = Switch(label="Dark", on_change=change_theme_func)

    def search_func(_:ControlEvent):
        if not search_field.value:
            search_field.error_text = "Please Enter City!"
            return page.update()

        page.splash         = ProgressBar()
        search_btn.disabled = True
        page.add(loading)
        page.update()

        search_value = search_field.value
        search_data  = new_event_loop().run_until_complete(get_weather(search_value))
        search_row   = Row([Text(search_data)], alignment="start")

        page.splash         = None
        search_btn.disabled = False
        page.remove(loading)
        page.update()

        page.add(search_row)

    search_field = TextField(label="Enter the City Name", width=300, tooltip="eg.: Seattle", hint_text="Ankara, Turkiye")
    search_btn   = ElevatedButton("Search", icon=icons.SEARCH, on_click=search_func)
    loading      = Row([ProgressRing()], alignment="start")

    page.add(Row([Row([search_field, search_btn]), change_theme], alignment="spaceBetween"))


flet(target=main_page)

Magic

search_data  = new_event_loop().run_until_complete(get_weather(search_value))

[FeodorFitsner]

So, this new_event_loop().run_until_complete() construct is needed to call async method from a sync one?

[keyiflerolsun]

asynchronous function can only be called inside an asynchronous function. Otherwise, it is necessary to create a new coroutine loop in this way.

[FeodorFitsner]

I see. Will dig into that, to see how to support asyncio in Flet.

[FeodorFitsner]

#128