Multiple answers in callback from ModalScreen?

[dirkpetersen]

I used this excellent example #2321 to create Yes/No Modal screen with callback, Now I would like do have 3 choices (Yes, No, Cancel) and tried to change the class to int instead of bool but that did not work. I want to confirm the row selection in a DataTable. Here is my code

class ScreenConfirm(ModalScreen[bool]):
    DEFAULT_CSS = """
    ScreenConfirm {
        align: center middle;
    }

    ScreenConfirm > Vertical {
        background: $secondary;
        width: auto;
        height: auto;
        border: thick $primary;
        padding: 2 4;
    }

    ScreenConfirm > Vertical > * {
        width: auto;
        height: auto;
    }

    ScreenConfirm > Vertical > Label {
        padding-bottom: 2;
    }

    ScreenConfirm > Vertical > Horizontal {
        align: right middle;
    }

    ScreenConfirm Button {
        margin-left: 2;
    }
    """

    def compose(self) -> ComposeResult:
        with Vertical():
            yield Label("Do you want to start this archiving job now?")
            with Horizontal():
                yield Button("Continue", id="continue")
                yield Button("Quit", id="quit")
                #yield Button("Return", id="return")

    def on_button_pressed(self, event: Button.Pressed) -> None:
        self.dismiss(result=event.button.id == "continue")

class TableHotspots(App[list]):

    BINDINGS = [("q", "request_quit", "Quit")]

    def __init__(self):
        super().__init__()
        self.myrow = []

    def compose(self) -> ComposeResult:
        table = DataTable()
        table.focus()
        table.zebra_stripes = True    
        table.cursor_type = "row"
        table.styles.max_height = "99vh"
        yield table
        #yield Footer()

    def on_mount(self) -> None:
        table = self.query_one(DataTable)
        fh = open(SELECTEDFILE, 'r')
        rows = csv.reader(fh)
        table.add_columns(*next(rows))
        table.add_rows(itertools.islice(rows,MAXHOTSPOTS))

    def accept_answer(self, answer: bool) -> None:
        # adds yesno answer as last element in list 
        if answer:
            self.exit(self.myrow+[True])
        else:
            self.exit(self.myrow+[False])

    def on_data_table_row_selected(self, event: DataTable.RowSelected) -> None:
        self.myrow = self.query_one(DataTable).get_row(event.row_key)
        #self.exit(self.query_one(DataTable).get_row(event.row_key))
        self.push_screen(ScreenConfirm(), callback=self.accept_answer)
        
    def action_request_quit(self) -> None:
        self.app.exit()

[davep]

When you say that you:

tried to change the class to int instead of bool but that did not work

how did it not work?

More generally though, you can return any value you like via dismiss; it's then down to how the callback function makes use of it. For example, in the above, you could type ScreenConfirm as str and then make the button handler as simple as:

    def on_button_pressed(self, event: Button.Pressed) -> None:
        self.dismiss(result=event.button.id)

and then your callback handler method could be:

    def accept_answer(self, answer: str) -> None:
        if answer == "continue":
            # do the continue thing
        elif answer == "quit":
            # do the quit thing
        else:
            # do the return thing

This is one of a number of different approaches you could use.

[dirkpetersen]

Ah, awesome, somehow I did not understand what

    self.dismiss(result=event.button.id == "continue")
    
    vs
    
    self.dismiss(result=event.button.id)
    
    did 

but now it is obvious .... Thanks very much