Run NiceGUI in a already created asyncio loop

[swaiku]

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Example Code

import asyncio
import logging
import signal

logger = logging.getLogger(__name__)
logging.basicConfig(level=logging.INFO)

# --- mocks minimalistes pour la repro ---
class DummyUART:
    async def connect(self):
        logger.info("UART connected")
    async def disconnect(self):
        logger.info("UART disconnected")

class DummyWindow:
    async def hardware_monitor_loop(self):
        while True:
            await asyncio.sleep(1)

    async def stop(self):
        logger.info("Window stopped")

async def main():
    logger.info("Starting application")

    uart = DummyUART()
    window = DummyWindow()

    await uart.connect()
    monitor_task = asyncio.create_task(window.hardware_monitor_loop())

    loop = asyncio.get_running_loop()
    stop_event = asyncio.Event()

    def shutdown():
        logger.info("Signal received, stopping...")
        stop_event.set()

    loop.add_signal_handler(signal.SIGINT, shutdown)
    loop.add_signal_handler(signal.SIGTERM, shutdown)

    @ui.page("/")
    def main_page():
        ui.button("click me")


    # here start the ui
    ui.run()

    await stop_event.wait()

    logger.info("Stopping tasks...")
    monitor_task.cancel()
    try:
        await monitor_task
    except asyncio.CancelledError:
        pass

    await window.stop()
    await uart.disconnect()
    logger.info("Clean exit done.")

if __name__ in {"__main__", "__mp_main__"}:
    asyncio.run(main())

Description

I would like to run NiceGUI in parallel, as if it did not have to manage my async loop. I would use the UI to configure and monitor my system, but I would like to be able to stop only the UI once it has been configured and have the program continue to run. I have not been able to find an example that does what I would like.

In my project, I use pyserial-asyncio for the uart communication. gpiod for controlling GPIOs pins, and later I gonna use aiomqtt for mqtt communication.

NiceGUI Version

2.23

Python Version

3.11

Browser

Firefox

Operating System

Linux

Additional Context

No response

[rodja]

Yes, you should be able to do it with hypercorn or uvicorn if you start the server yourself. You just need to configure middlewares etc similar to what run_with or run does beforehand.