Having trouble pushing and getting data from multiple screens

[sid-rotor]

Hello,
I am new to using textual and am running into an issue. I would like to have some screens that let the user configure options. At the start of the app, I want these screens to pop up, then later I will bind some buttons to them so that the user can change these settings. I have tried to implement it by pushing the screens in on_mount, but am having trouble getting the data out. My statics on the main app both show None.
I am using the await call to push_screen as per this example: https://textual.textualize.io/guide/screens/#waiting-for-screens. When I tried two callback versions commented out, I only got the data for one or the other widgets. What might I be doing wrong? I've copied my runnable example below, thanks for any advice.

from textual import on, work
from textual.reactive import reactive
from textual.screen import Screen
from textual.app import App, ComposeResult
from textual.widgets import Button, Footer, Header, Static, Input

from typing import Optional


class ScreenA(Screen[int]):
    @on(Input.Submitted)
    def handle_input_submit(self, event: Input.Submitted) -> None:
        self.dismiss(7)

    def compose(self) -> ComposeResult:
        yield Input()


class ScreenB(Screen[str]):

    def on_button_pressed(self, event: Button.Pressed) -> None:
        self.dismiss("screenb")

    def compose(self) -> ComposeResult:
        yield Button("Dismiss ScreenB")


class TestApp(App):
    int_output: reactive[Optional[int]] = reactive(None, recompose=True)
    str_output: reactive[Optional[str]] = reactive(None, recompose=True)

    @work
    async def on_mount(self) -> None:
        self.int_output = await self.push_screen(ScreenA())
        self.str_output = await self.push_screen(ScreenB())

    # Version A
    # def on_mount(self) -> None:
    #     def cbA(value: Optional[int]) -> None:
    #         self.int_output = value
    #
    #     def cbB(value: Optional[str]) -> None:
    #         self.str_output = value
    #
    #     self.push_screen(ScreenA(), cbA)
    #     self.push_screen(ScreenB(), cbB)

    # Version B
    # def on_mount(self) -> None:
    #     def cbA(value: Optional[int]) -> None:
    #         self.int_output = value
    #
    #         def cbB(value: Optional[str]) -> None:
    #             self.str_output = value
    #
    #         self.push_screen(ScreenB(), cbB)
    #
    #     self.push_screen(ScreenA(), cbA)

    def compose(self) -> ComposeResult:
        yield Header()
        yield Static(str(self.int_output))
        yield Static(str(self.str_output))
        yield Footer()


app = TestApp()
app.run()

[davep]

I am using the await call to push_screen as per this example: textual.textualize.io/guide/screens#waiting-for-screens.

Note that that example doesn't use push_screen, it uses push_screen_wait.

[sid-rotor]

Well that is quite embarrassing. Thank you, the await implementation with push_screen_wait works as expected.

More for curiosity than anything else, do you have an idea of why the callback versions don't work as expected?

[davep]

I didn't really look at that; but at a quick glance the issue is you're pushing two screens at once -- the callback version isn't going to wait for the first callback to fire before pushing the second screen. If you're wanting one screen after another to pop up using the callback method you'd probably want to be pushing the second screen in the callback of the first.