How can I create a websocket JSObject in brython?

Question

I'm trying to use Brython to run Python code in the browser, and to use websockets in that Python code.

I have working JavaScript code that can connect to the Websocket echo server at http://www.websocket.org/echo.html.

According to the documentation, the function JSObject can be used to manipulate JavaScript objects in Brython, but I can't get it to work using either ws = JSObject(WebSocket("ws://echo.websocket.org/")) or ws = JSObject(new WebSocket("ws://echo.websocket.org/")).

How can I make a simple "Hello World" example connecting to the echo server, in Python code, using Brython?

_{See also How to import library using Brython for using libraries that aren't built in to Brython (including the usual Python standard library).}

score 5 · Accepted Answer · answered Jul 29 '13 at 12:54

Here is an example using the built-in websocket() function, included in py_websocket, and the server echo.websocket.org :

<html>
<head>
<meta charset="iso-8859-1">
<script src="/src/brython.js"></script>

<script type="text/python3">
def on_open():
    # Web Socket is connected, send data using send()
    data = doc["data"].value
    if data:
        ws.send(data)
        alert("Message is sent")

def on_message(evt):
    # message received from server
    alert("Message received : %s" %evt.data)

def on_close(evt):
    # websocket is closed
    alert("Connection is closed")

ws = None
def _test():
    global ws
    # open a web socket
    ws = websocket("wss://echo.websocket.org")
    # attach functions to web sockets events
    ws.on_open = on_open
    ws.on_message = on_message
    ws.on_close= on_close

def close_connection():
    ws.close()
</script>
</head>
<body onload="brython(1)">
<input id="data">
<button onclick="_test()">Run WebSocket</button>
<p><button onclick="close_connection()">Close connection</button>
</body>
</html>

The code should be self-explanatory. The Brython site needs to be completed with more documentation about web sockets

How can I create a websocket JSObject in brython?

1 Answers1