testbed/Textualize__textual/docs/examples/events/dictionary.py

import asyncio

try:
    import httpx
except ImportError:
    raise ImportError("Please install httpx with 'pip install httpx' ")

from rich.json import JSON
from textual.app import App, ComposeResult
from textual.containers import Vertical
from textual.widgets import Static, Input


class DictionaryApp(App):
    """Searches ab dictionary API as-you-type."""

    CSS_PATH = "dictionary.css"

    def compose(self) -> ComposeResult:
        yield Input(placeholder="Search for a word")
        yield Vertical(Static(id="results"), id="results-container")

    async def on_input_changed(self, message: Input.Changed) -> None:
        """A coroutine to handle a text changed message."""
        if message.value:
            # Look up the word in the background
            asyncio.create_task(self.lookup_word(message.value))
        else:
            # Clear the results
            self.query_one("#results", Static).update()

    async def lookup_word(self, word: str) -> None:
        """Looks up a word."""
        url = f"https://api.dictionaryapi.dev/api/v2/entries/en/{word}"
        async with httpx.AsyncClient() as client:
            results = (await client.get(url)).text

        if word == self.query_one(Input).value:
            self.query_one("#results", Static).update(JSON(results))


if __name__ == "__main__":
    app = DictionaryApp()
    app.run()