使用 Flask-Login 在 Flask 中获取“str”对象没有属性“is_authenticated”

我正在尝试使用 Flask-Login 设置 Flask 登录。我有一个供用户使用的 CouchDB；客户文档有一个称为“用户”的对象。

class User(UserMixin):
    def __init__ (self, user) :
        self.name = user['name']
        self.password = user['password']
        self.id= user['id']

    def is_active(self):
        return True

    def is_authenticated(self):
        return True

    def is_anonymous(self):
        return False

    def get_id(self):
        return str(self.id)


def check_user(id):
    for row in db.query(map_auth):
        if row.value['id'] == id:
            authUser = User(row.value)
            return authUser
        else:
            return "User not found in database"

@login_manager.user_loader
def load_user(id):
    return check_user(id)


@app.route('/login/', methods=['GET','POST'])
def login():  
    if request.method == 'POST':
        for row in db.query(map_auth):
            if row.value['name'] == request.form['name'] and row.value['password'] == request.form['password']:
                authUser = User(row.value)
        flask_login.login_user(authUser)
        app.logger.debug(authUser.name)
        app.logger.debug(authUser.is_authenticated())
        app.logger.debug(authUser.is_active())
        return redirect(url_for('protected'))
    return render_template('login.html')

map_auth是来自 python-couchdb 的视图函数。该视图返回一个 JSON 列表，其中包含用户的以下信息：{"name": "xxxx", "id":1, "password": "password"}.

我验证了User类通过在 Python shell 中模拟它来独立工作。当我在 Flask 中使用它时，出现以下错误。

  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 2000, in __call__
    return self.wsgi_app(environ, start_response)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1991, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1567, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1988, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1641, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1544, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1639, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1625, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/usr/local/lib/python2.7/dist-packages/flask_login.py", line 790, in decorated_view
    elif not current_user.is_authenticated:
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/local.py", line 343, in __getattr__
    return getattr(self._get_current_object(), name)
AttributeError: 'str' object has no attribute 'is_authenticated'

我已经验证过authUser我使用过的对象有is_authenticated() true.

The user_loader函数（在你的情况下逻辑是check_user）应该返回None如果用户 ID 无效。在你的情况下是一个字符串"User not found in database"返回，这会创建您遇到的异常。

Return None如果用户 ID 无效。

文档 https://flask-login.readthedocs.io/en/latest/#how-it-works:

它应该返回None (不引发异常) 如果 ID 无效。 （在这种情况下，该 ID 将从会话中手动删除，处理将继续。）