websocket client

client.py

#!/usr/bin/env python3
import sys

import asyncio
import json
import websockets

async def hello():
    uri = "ws://localhost:8888"

    async with websockets.connect(uri) as websocket:
        try:
            while True:
                await websocket.send(json.dumps({"type": "info", 'action': 'minus'}))
                await websocket.recv()
                await asyncio.sleep(0.5)
        finally:
            await websocket.send(json.dumps({"type": "disconnect"}))


async def amain():
    await hello()
    return 0


def main():
    asyncio.run(hello())


if __name__ == "__main__":
    sys.exit(main())

server.py

#!/usr/bin/env python

# WS server example that synchronizes state across clients

import asyncio
import json
import logging
import websockets
from rich.console import Console

console = Console()


logging.basicConfig()

STATE = {"value": 0}

USERS = set()


def state_event():
    return json.dumps({"type": "state", **STATE})


def users_event():
    return json.dumps({"type": "users", "count": len(USERS)})


async def notify_state():
    if USERS:  # asyncio.wait doesn't accept an empty list
        message = state_event()
        await asyncio.wait([user.send(message) for user in USERS])


async def notify_users():
    if USERS:  # asyncio.wait doesn't accept an empty list
        message = users_event()
        await asyncio.wait([user.send(message) for user in USERS])


async def register(websocket):
    USERS.add(websocket)
    await notify_users()


async def unregister(websocket):
    USERS.remove(websocket)
    await notify_users()


async def counter(websocket, path):
    # register(websocket) sends user_event() to websocket
    await register(websocket)
    try:
        await websocket.send(state_event())
        async for message in websocket:
            console.print(message)
            data = json.loads(message)
            if data["action"] == "minus":
                STATE["value"] -= 1
                await notify_state()
            elif data["action"] == "plus":
                STATE["value"] += 1
                await notify_state()
            else:
                logging.error("unsupported event: %s", data)
    finally:
        await unregister(websocket)


start_server = websockets.serve(counter, "localhost", 8888)
console.print("serveur demarre")
asyncio.get_event_loop().run_until_complete(start_server)
asyncio.get_event_loop().run_forever()

server_starlette.py

from starlette.applications import Starlette
import starlette.websockets
import uvicorn
from rich.console import Console

console = Console()

app = Starlette()


@app.websocket_route('/')
async def websocket_endpoint(websocket):
    await websocket.accept()
    try:
        # Process incoming messages
        while True:
            mesg = await websocket.receive_json(mode="text")
            if mesg["type"] == "disconnect":
                try:
                    await websocket.receive_bytes()
                except starlette.websockets.WebSocketDisconnect:
                    return
                else:
                    raise Exception("client did not disconnect")

            console.print(f"messsage to submit {mesg}")
            hmm = await websocket.send_json(mesg)
            console.print(f"hmmm {hmm}")
            console.print(f"messsage submitted {mesg}")
    finally:
        await websocket.close()

if __name__ == '__main__':
    uvicorn.run(app, host='127.0.0.1', port=8888)