在 python-socketio Client() 的事件处理程序中访问 Flask 应用程序上下文

Question

我正在尝试访问

python-socketio

的事件处理程序

on_tick()

中的 Flask 应用程序上下文，并且出现错误 -

(...)
 File "H:\Python\autotrader2\venv\lib\site-packages\werkzeug\local.py", line 316, in __get__
    obj = instance._get_current_object()  # type: ignore[misc]
  File "H:\Python\autotrader2\venv\lib\site-packages\werkzeug\local.py", line 513, in _get_current_object
    raise RuntimeError(unbound_message) from None
RuntimeError: Working outside of application context.

This typically means that you attempted to use functionality that needed
the current application. To solve this, set up an application context
with app.app_context(). See the documentation for more information.

尝试提取一个较大程序的自给自足的微型版本 -

import socketio
from flask import current_app

class MySocketIOClient:
    def __init__(self):
        self.sio = socketio.Client()
        self.sio.connect("https://feeds.sio.server",
                         headers={"User-Agent": "python-socketio[client]/socket"},
                         auth={"user": "user_id", "token": "session_token"},
                         transports="websocket")

    def execute(self):
        # with current_app.app_context():  # Does not work
        with current_app.test_request_context('/'):  # Does not work
            self.sio.on('update', self.on_tick)
            # self.sio.wait()  # Does not work either

    def on_tick(self, tick):
        print(tick)
        # Error: working outside application context
        print("APP_TIMEZONE={}".format(current_app.config.get('APP_TIMEZONE')))  

if __name__ == '__main__':
    MySocketIOClient().execute()

如何在事件处理程序中访问 Flask 的应用程序上下文（或请求上下文）？

Answer 1

current_app

仅在已经安装了应用程序上下文时才有效，因此它对您的情况没有用。

为此，您需要导入您的应用程序实例：

from x import app

class MySocketIOClient:
    # ...

    def on_tick(self, tick):
        print("APP_TIMEZONE={}".format(app.config.get('APP_TIMEZONE')))  

这里我使用

x

作为包含 Flask 应用程序实例的模块的占位符。