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为Flask设置登录名。我有一个针对用户的CouchDB；客户文档中有一个称为“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。该视图为用户返回一个JSON列表，其中包含以下信息：{"name": "xxxx", "id":1, "password": "password"}。

我通过User在Python Shell中进行仿真来验证该类是否独立工作。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'

我已经验证了authUser我使用的对象是否is_authenticated()正确。