我已经实现了 tutorial 中给出的 Django Channels 。聊天工作正常，我可以在群组中发送和接收消息。
但是当我尝试从网络套接字向聊天 channel 发送消息时，它不会显示该消息。相反，会填充错误。但是，我能够从 Channels chat 接收消息到我的 Web 套接字 html 页面。
websocket.html
<!DOCTYPE html>
<meta charset="utf-8" />
<title>WebSocket Test</title>
<script language="javascript" type="text/javascript">
var wsUri = "ws://localhost:8000/ws/power/room/";
var output;
function init()
{
output = document.getElementById("output");
testWebSocket();
testWebSocket();
}
function testWebSocket()
{
websocket = new WebSocket(wsUri);
websocket.onopen = function(evt) { onOpen(evt) };
websocket.onclose = function(evt) { onClose(evt) };
websocket.onmessage = function(evt) { onMessage(evt) };
websocket.onerror = function(evt) { onError(evt) };
}
function onOpen(evt)
{
writeToScreen("CONNECTED");
doSend("WebSocket rocks");
}
function onClose(evt)
{
writeToScreen("DISCONNECTED");
}
function onMessage(evt)
{
writeToScreen('<span style="color: blue;">RESPONSE: ' + evt.data+'</span>');
websocket.close();
}
function onError(evt)
{
writeToScreen('<span style="color: red;">ERROR:</span> ' + evt.data);
}
function doSend(message)
{
writeToScreen("SENT: " + message);
websocket.send(message);
}
function writeToScreen(message)
{
var pre = document.createElement("p");
pre.style.wordWrap = "break-word";
pre.innerHTML = message;
output.appendChild(pre);
}
window.addEventListener("load", init, false);
</script>
<h2>WebSocket Test</h2>
<div id="output"></div>
consumers.py
class EchoConsumer(AsyncWebsocketConsumer):
async def connect(self):
self.room_name = self.scope['url_route']['kwargs']['room_name']
self.room_group_name = 'chat_%s' % self.room_name
# Join room group
await self.channel_layer.group_add(
self.room_group_name,
self.channel_name
)
await self.accept()
async def disconnect(self, close_code):
# Leave room group
await self.channel_layer.group_discard(
self.room_group_name,
self.channel_name
)
# Receive message from WebSocket
async def receive(self, text_data):
text_data_json = json.loads(text_data)
message = text_data_json['message']
# Send message to room group
await self.channel_layer.group_send(
self.room_group_name,
{
'type': 'chat_message',
'message': message
}
)
# Receive message from room group
async def chat_message(self, event):
message = event['message']
# Send message to WebSocket
await self.send(text_data=json.dumps({
'message': message
}))
我在 channel 服务器上收到的错误是
WebSocket HANDSHAKING /ws/power/room/ [127.0.0.1:56879]
WebSocket CONNECT /ws/power/room/ [127.0.0.1:56879]
Exception inside application: Expecting value: line 1 column 1 (char 0)
File "C:\Program Files\Python37\lib\site-packages\channels\sessions.py", line 179, in __call__
return await self.inner(receive, self.send)
File "C:\Program Files\Python37\lib\site-packages\channels\middleware.py", line 41, in coroutine_call
await inner_instance(receive, send)
File "C:\Program Files\Python37\lib\site-packages\channels\consumer.py", line 59, in __call__
[receive, self.channel_receive], self.dispatch
File "C:\Program Files\Python37\lib\site-packages\channels\utils.py", line 52, in await_many_dispatch
await dispatch(result)
File "C:\Program Files\Python37\lib\site-packages\channels\consumer.py", line 73, in dispatch
await handler(message)
File "C:\Program Files\Python37\lib\site-packages\channels\generic\websocket.py", line 196, in websocket_receive
await self.receive(text_data=message["text"])
File "C:\Users\Suleman\PycharmProjects\power\myChannels\consumers.py", line 39, in receive
text_data_json = json.loads(text_data)
File "C:\Program Files\Python37\lib\json\__init__.py", line 348, in loads
return _default_decoder.decode(s)
File "C:\Program Files\Python37\lib\json\decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "C:\Program Files\Python37\lib\json\decoder.py", line 355, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
Expecting value: line 1 column 1 (char 0)
WebSocket DISCONNECT /ws/power/room/ [127.0.0.1:56879]
最佳答案
有效负载必须是有效的 JSON 对象，您仅发送一个字符串。 尝试改变你的功能:
function doSend(message) {
writeToScreen("SENT: " + message);
websocket.send(JSON.stringify({message: message}();
}
关于python - Django Channels 与 Web 套接字的连接，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/54423507/