Example: Chat¶

A multi-user chat room powered entirely by Pyplet. Messages arrive over WebSockets, the UI updates through Pyodide DOM calls, and no JavaScript is required.

Location¶

• Repository: https://github.com/cetic/pyplet_examples
• Path: apps/pyplet_examples/examples/chat_*
• Client entry point: chat_client.py
• Server loop: chat_server.py

Fetch or refresh the examples submodule:

git submodule update --init --recursive

Highlights¶

• chat_client.py:26 unwraps the handshake payload to display the assigned username.

async def websocket_client_loop(ws: pyplet.WebSocket):
    init = decode(await ws.receive())
    assert init["type"] == "init"
    render(f"<b>Logged in as {init['name']}</b>")

• chat_client.py:31 uses pyodide.create_proxy to wire DOM events directly to the WebSocket.

    @create_proxy
    async def submit(_):
        message = input.value
        input.value = ""
        await ws.send(message)

    input.addEventListener("change", submit)

• chat_server.py:35 rebroadcasts every message to all connected clients.

    while True:
        msg = await ws.receive()
        if msg is ws.closing_message:
            break
        msg = json.dumps({"type": "message", "name": name, "message": msg})
        await asyncio.gather(*(s.send(msg) for s in sockets.values()))

• chat_server.py:42 manages the user pool, removing sockets when clients disconnect.

    del sockets[name]
    available.insert(0, name)

This example demonstrates two-way real-time messaging with minimal boilerplate—ideal for exploring Pyplet’s WebSocket helpers.