FastAPI SocketIO

[Forceres]

I've seen some kinds of SocketIO and FastAPI integrations, but all of them used a lot of global variables (objects). And I would like to know how can we avoid them or fully refuse to use them in that case?

[miguelgrinberg]

Not sure what integrations you have seen, but to use Socket.IO you need just a Server or AsyncServer instance. This is typically a global variable, but you can also embed it in a class, along with all the event handlers.

[Forceres]

Thanks for the answer, but can I embed it in a class, and then register events without global instance, for example, by class static method?

[miguelgrinberg]

Let me show you a couple of options.

Here is a standard mini-server, using a global sio variable:

sio = socketio.AsyncServer()

@sio.event
async def connect(sid, environ, auth):
    print('incoming connection')

Here is the same using the factory function pattern:

def create_socketio_server():
    sio = socketio.AsyncServer()

    @sio.event
    async def connect(sid, environ, auth):
        print('incoming connection')

    return sio

And here is an OOP version:

class SocketIOServer:
    def __init__(self):
        self.sio = socketio.AsyncServer()
        self.sio.on('connect', self.on_connect)

    async def on_connect(self, sid, environ, auth):
        print('incoming connection')