9.5. Textual Integration

Wire a ComponentVMOf[M] to a Textual TUI widget through Textual's reactive descriptors.

9.5.1. Reactivity primitive

Textual widgets re-render when a reactive(...) attribute changes. VMx VMs publish PropertyChangedMessage[T] to their MessageHub. The adapter subscribes to the hub and forwards changes into the widget's reactive attributes.

9.5.2. Mapping

Textual	VMx
reactive("value")	PropertyChangedMessage[T] on MessageHub
Button.action_press	RelayCommand.execute()
ListView items	ObservableList[T] + CollectionChangedMessage
App.call_from_thread	RxDispatcher.asyncio(loop).foreground

9.5.3. Adapter skeleton

from textual.widget import Widget
from textual.reactive import reactive
import reactivex.operators as ops
from vmx import ComponentVMOf, Message, MessageHubProto, PropertyChangedMessage, RelayCommand

class BindableWidget(Widget):
    title: reactive[str] = reactive("")
    status_text: reactive[str] = reactive("")

    def __init__(self, vm: ComponentVMOf[Note], hub: MessageHubProto[Message],
                 save_command: RelayCommand):
        super().__init__()
        self._vm = vm
        self._save_command = save_command
        self._sub = hub.messages.pipe(
            ops.filter(lambda m: isinstance(m, PropertyChangedMessage)
                                 and m.sender is vm),
        ).subscribe(self._on_property_changed)

    def _on_property_changed(self, msg: PropertyChangedMessage[object]) -> None:
        if msg.property_name == "model":
            self.title = self._vm.model.title
        elif msg.property_name == "status":
            self.status_text = str(self._vm.status)

    def on_unmount(self) -> None:
        self._sub.dispose()

For buttons: bind the widget's action_* handler to call self._save_command.execute(None).

9.5.4. Fuller example

• examples/python/textual/inspector/ — a Textual viewer for any VMx tree, demonstrating the hub-subscription pattern at scale.
• examples/python/textual/notes_showcase/ — the Notes-Showcase Textual flagship: full WorkspaceVM with bind_property / bind_command helpers (shipped in v2.2.0; ThemeVM added in v2.4.0).