Run event after window close

[certainlyWrong]

Hello everyone, I would like to know if it is possible to register an event to be executed after closing the window.

[FeodorFitsner]

Would checking for close on Page.on_window_event work?

[dd-rongfa]

Do Not Work

[ndonkoHenri]

Follow the example here: https://flet.dev/docs/controls/page/#window_destroy. Inside the window_event callback, register your said event in a thread, then explicitly call the window_destroy.

[certainlyWrong]

Thank you, this was exactly what I wanted.

[certainlyWrong]

Just to clarify, I didn't find anything talking about this in the Flet documentation. Is the documentation out of date or did I miss it?

[ndonkoHenri]

Talking about what?
I gave you links right?

[3mora2]

please add This method could be used with page.window_prevent_close = True to implement app exit confirmation also with on_window_event in documentation

[torablien]

hey @FeodorFitsner @ndonkoHenri, is it expected that Page.on_window_event only emits the close event if page.window_prevent_close = True?

It feels a bit confusing to set window_prevent_close = True if you don't actually want to prevent close, but just listen for the close event so you can do something else (e.g. gracefully close threads). I initially thought it was a bug but wanted to check if this was behavior you intended before opening an issue. Thanks!

[dd-rongfa]

So what’s the finally anwser？

[ez404-36]

В документации flet (я использую 0.28.3) сказано сделать так:

def on_event(e):
    if e.data == 'close':
       # bla-bla-bla your code before closing app
       page.window.destroy()

page.window.prevent_close = True
page.window.on_event = on_event

Это работает, но есть нюанс - процесс закрытия приложения занимает около 10 секунд, что не позволительно.
В моем случае мне надо было всего лишь сделать пару записей в БД перед закрытием,
и проблема решилась следующим способом:

page.on_disconnect = on_disconnect # coroutine

async def on_disconnect(e):
    # your awesome code (will be executed after closing flet window)