Simple heirarchical program isn't picking up sent messages

[fshriver]

Hello,

I'm trying to put together a simple program based on OptionList, however I can't seem to get the parent widget to listen/pick up on messages from child widgets. See below MVE:

from textual.app import App, ComposeResult
from textual.widget import Widget
from textual.widgets import Footer
from textual.widgets import OptionList

class DefaultOptions(Widget):

    def __init__(self) -> None:
        super().__init__()

    def compose(self) -> ComposeResult:
        yield OptionList(
            'Option 1',
            'Option 2'
        )

    def on_option_list_selected(self, event: OptionList.OptionSelected) -> None:
        print('\n\nbark\n\n')


class OptionSelector(App):

    def compose(self) -> ComposeResult:
        yield DefaultOptions()
        yield Footer()

if __name__ == "__main__":
    OptionSelector().run()

In this case, I just need the DefaultOptions widget to "barK' when an option is selected. I've confirmed printing works previously by putting in a print statement in compose() and having it successfully print to the debug console. However, while that worked, and I can see in the debug console that OptionList.OptionSelected event is being sent, on_option_list_selected() is never called as it never prints "bark" to the debug console. Is there something I'm missing or some fundamental problem with this MVE I'm not catching?

Also see below output from the textual console:

[19:10:40] EVENT                                                                                                         message_pump.py:697
Key(key='enter', character='\r', name='enter', is_printable=False, aliases=['enter', 'ctrl+m']) >>> OptionList() method=<Widget.on_key>
[19:10:40] EVENT                                                                                                         message_pump.py:697
Key(key='enter', character='\r', name='enter', is_printable=False, aliases=['enter', 'ctrl+m']) >>> DefaultOptions() method=<Widget.on_key>
[19:10:40] EVENT                                                                                                         message_pump.py:697
Key(key='enter', character='\r', name='enter', is_printable=False, aliases=['enter', 'ctrl+m']) >>> Screen(id='_default') 
method=<Widget.on_key>
[19:10:40] EVENT                                                                                                         message_pump.py:697
Key(key='enter', character='\r', name='enter', is_printable=False, aliases=['enter', 'ctrl+m']) >>> OptionSelector(title='OptionSelector', 
classes={'-dark-mode'}) method=<App.on_key>
[19:10:40] SYSTEM                                                                                                                app.py:2826
<action> namespace=OptionList() action_name='select' params=()
[19:10:40] EVENT                                                                                                         message_pump.py:706
OptionSelected(option_list=OptionList(), option=<textual.widgets._option_list.Option object at 0x7f6f294fe750>, option_id=None, 
option_index=1) >>> OptionList() method=None
[19:10:40] EVENT                                                                                                         message_pump.py:706
OptionSelected(option_list=OptionList(), option=<textual.widgets._option_list.Option object at 0x7f6f294fe750>, option_id=None, 
option_index=1) >>> DefaultOptions() method=None
[19:10:40] EVENT                                                                                                         message_pump.py:706
OptionSelected(option_list=OptionList(), option=<textual.widgets._option_list.Option object at 0x7f6f294fe750>, option_id=None, 
option_index=1) >>> Screen(id='_default') method=None
[19:10:40] EVENT                                                                                                         message_pump.py:706
OptionSelected(option_list=OptionList(), option=<textual.widgets._option_list.Option object at 0x7f6f294fe750>, option_id=None, 
option_index=1) >>> OptionSelector(title='OptionSelector', classes={'-dark-mode'}) method=None

[davep]

The problem is the handler should be called on_option_list_option_selected. It might be worth having a look back over the documentation for how handlers are named. You may also find that you prefer to use the @on decorator to create handlers as you'll then have the typing system on your side (if you use any sort of type checking).