How do I create an interactive button?

[ethansocal]

Is it possible to create a button that when pressed, triggers an event?

[willmcgugan]

Documentation is coming, but the basic principle is you have a widget with an on_click method and you emit a message.

from textual.message import Message

class ButtonPressed(Message, bubble=True):
    pass

class Button(Widget):
    async def on_click(self, event: events.Click) -> None:
        await self.emit(ButtonPressed(self))

Then in the parent view / app you can catch the message with the following:

async def message_button_event(self, message: ButtonPressed) -> None:
    # button handler

[willmcgugan]

Check out the updated calculator example.

[ThatXliner]

How about on a custom Widget?

[Raphasha27]

Use the @on.button decorator with a Button widget:

from textual.app import App, ComposeResult
from textual.widgets import Button, Static

class CounterApp(App):
    def compose(self) -> ComposeResult:
        yield Button("Click me!", id="my-button", variant="primary")
        yield Static("Clicks: 0", id="counter")

    def on_button_pressed(self, event: Button.Pressed) -> None:
        """Handle button press."""
        counter = self.query_one("#counter", Static)
        current = int(counter.renderable.split(": ")[1])
        counter.update(f"Clicks: {current + 1}")

app = CounterApp()
app.run()

For a styled button:

yield Button("Submit", variant="success")    # green
yield Button("Cancel", variant="error")      # red
yield Button("Info", variant="primary")      # blue
yield Button("Default", variant="default")   # gray

To dynamically create buttons:

from textual.widgets import Button

class DynamicApp(App):
    def on_mount(self) -> None:
        for i in range(5):
            btn = Button(f"Item {i + 1}", id=f"btn-{i}")
            self.mount(btn)

    def on_button_pressed(self, event: Button.Pressed) -> None:
        self.notify(f"Pressed: {event.button.label}")

Buttons respond to click, keyboard focus (Enter/Space), and emit Button.Pressed messages that you handle with on_button_pressed().