如何从 websocket 端点外部发出 websocket 消息？

Question

我正在使用 Flask in which I also use Websockets using Flask-socketIO 构建网站，但有一件事我不明白。

我构建了一个聊天功能。当一个用户发送一条消息时，我使用 websockets 将该消息发送到服务器，然后我从同一个调用中将消息发送给另一个用户：

@socketio.on('newPM', namespace='/test')
@login_required_with_global
def io_newMessage(theJson):
    emit('message', {'message': theJson['message']}, room=str(theJson['toUserId']))

但是假设我想在保存文件时向用户发送一条消息。这意味着我需要从发布文件的视图中发出一条消息。所以根据 flask_socketio docs 我可以在 emit 中添加一个命名空间。所以我写了这个：

@app.route('/doc', methods=['POST'])
@login_required
def postDoc():
    saveDocument(request.files['file'], g.user.id)
    emit('my response', {'data': 'A NEW FILE WAS POSTED'}, room=current_user.id, namespace='/test')
    return jsonify({'id': str(doc.id)})

但是看到下面的堆栈跟踪，命名空间仍然存在问题； werkzeug 有一个 AttributeError: 'Request' object has no attribute 'namespace'。

有人知道我做错了什么吗？或者这是 flask_socketio 中的错误？欢迎所有提示！

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1820, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1403, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/usr/local/lib/python2.7/dist-packages/flask_login.py", line 758, in decorated_view
    return func(*args, **kwargs)
  File "/home/vg/app/views.py", line 768, in emitNotificationCount
    emit('menuInit', emitJson, room=current_user.id, namespace='/test')
  File "/usr/local/lib/python2.7/dist-packages/flask_socketio/__init__.py", line 444, in emit
    return request.namespace.emit(event, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/local.py", line 338, in __getattr__
    return getattr(self._get_current_object(), name)
AttributeError: 'Request' object has no attribute 'namespace'

Answer 1

引用 Miguel Grinberg 在 an open issue page on the Flask-SocketIO GitHub 上的回复：

When you want to emit from a regular route you have to use socketio.emit(), only socket handlers have the socketio context necessary to call the plain emit().

举个例子：

from flask_socketio import SocketIO

app = Flask(__name__)
app.config.from_object('config')
socketio = SocketIO(app)

@app.route('/doc', methods=['POST'])
def postDoc():
    saveDocument(request.files['file'], g.user.id)
    socketio.emit('my response', {'data': 'A NEW FILE WAS POSTED'}, room=current_user.id)
    return jsonify({'id': str(doc.id)})

如何从 websocket 端点外部发出 websocket 消息？

How to emit websocket message from outside a websocket endpoint?

python

websocket

flask

socket.io

flask-socketio