how to get result from document.addEventListener("keydown")?

[wcarvalho]

I want to have python functions which respond to different key presses. I'm trying to add an event listener but I can't figure out how to route it to a python function. This is what I have so far...

python:

from fasthtml.common import *

secret_key = "your-secret-key-here"

app = FastHTML(
    ws_hdr=True,
    middleware=[
        Middleware(SessionMiddleware, secret_key=secret_key)
    ],
)
async def on_connect(self, send):
    pass

async def on_disconnect(self):
    pass

@app.ws('/ws', conn=on_connect, disconn=on_disconnect)
async def ws(msg: str, send):
    print(msg)

@app.route("/")
async def get(request: Request):
   return Div(
            Script("""
                const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:';
                const host = window.location.host;
                const wsUrl = `${protocol}//${host}/ws`;

                const socket = new WebSocket(wsUrl);
                console.log('socket created');
                document.addEventListener("keydown", function(event) {
                    console.log(event.key);
                    socket.send(JSON.stringify({key: event.key}));
                });
            """)
)

I get the following error:

Traceback (most recent call last):
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/uvicorn/protocols/websockets/websockets_impl.py", line 244, in run_asgi
    result = await self.app(self.scope, self.asgi_receive, self.asgi_send)  # type: ignore[func-returns-value]
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/uvicorn/middleware/proxy_headers.py", line 70, in __call__
    return await self.app(scope, receive, send)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/applications.py", line 123, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/middleware/errors.py", line 151, in __call__
    await self.app(scope, receive, send)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/middleware/sessions.py", line 85, in __call__
    await self.app(scope, receive, send_wrapper)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/middleware/sessions.py", line 85, in __call__
    await self.app(scope, receive, send_wrapper)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/middleware/exceptions.py", line 65, in __call__
    await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/_exception_handler.py", line 64, in wrapped_app
    raise exc
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    await app(scope, receive, sender)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/routing.py", line 756, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/routing.py", line 776, in app
    await route.handle(scope, receive, send)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/routing.py", line 373, in handle
    await self.app(scope, receive, send)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/endpoints.py", line 90, in dispatch
    raise exc
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/starlette/endpoints.py", line 82, in dispatch
    await self.on_receive(websocket, data)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/fasthtml/core.py", line 237, in _recv
    async def _recv(self, ws, data): await _generic_handler(recv, ws, data)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/fasthtml/core.py", line 227, in _generic_handler
    wd = _wrap_ws(ws, loads(data) if data else {}, signature(handler).parameters)
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/fasthtml/core.py", line 215, in _wrap_ws
    return [_find_wsp(ws, data, hdrs, arg, p) for arg,p in params.items()]
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/fasthtml/core.py", line 215, in <listcomp>
    return [_find_wsp(ws, data, hdrs, arg, p) for arg,p in params.items()]
  File "/Users/wilka/miniforge3/envs/web-dev/lib/python3.10/site-packages/fasthtml/core.py", line 206, in _find_wsp
    if res is empty or res is None: res = headers.get(snake2hyphens(arg), None)
NameError: name 'headers' is not defined. Did you mean: 'Header'?

am I doing something wrong or is this a bug in the library?