Flask-login

Question

我正在为运行匿名在线实验设置一个烧瓶应用程序。如何通过登录管理器的 current_user 对象跟踪匿名参与者？

当用户是匿名用户时，current_user 设置为 AnonymousUserMixin。我试图为 AnonymousUserMixin 分配一个 id 变量（例如通过 uuid.uuid4() ）以不具有 current_user=None 但它不再是 ORM 对象了。我尝试遵循此 post (How to track anonymous users with Flask) 的第二个答案的建议，但我缺乏如何将描述的方式转换为实际代码的知识。

所以我得到了错误消息 'AnonymousUserMixin' object has no attribute '_sa_instance_state' 我似乎无法解决。

关于如何对匿名用户使用 current_user 对象有什么建议吗？

这里是一些相关的代码部分[编辑：根据@Roch 的建议调整了代码]：

models.py

from website import db


# models for database structure
class DemographicData(db.Model):
    __tablename__ = 'demographic_data'
    id = db.Column(db.Integer, primary_key=True)
    gender = db.Column(db.String(1), nullable=False)
    age = db.Column(db.Integer, nullable=False)
    nationality = db.Column(db.String(50), nullable=False)
    # create relationships to the other models to link them to the demographicData
    consentRequest = db.relationship('ModalData', backref='participant_bref', lazy=True)


    def __repr__(self):
        return f"demographicData('{self.id}', '{self.gender}', '{self.age}', '{self.nationality}')"


class ModalData(db.Model):
    __tablename__ = 'modal_data'
    id = db.Column(db.Integer, primary_key=True)
    participantId = db.Column(db.Integer, db.ForeignKey('demographic_data.id'), nullable=False)
    consent = db.Column(db.String(3), nullable=False)

    def __repr__(self):
        return f"modalData('{self.participantId}', '{self.consent}')"

routes.py

from flask import render_template, url_for, redirect, request, session
from website import app, db
from website.models import DemographicData, ModalData
from website.questionnaires import DemographicsForm



@app.before_request
def make_session_permanent():
    session.permanent = True



# route to demographic information form
@app.route("/demographics", methods=['GET', 'POST'])
def demographics():
    form = DemographicsForm()
    if form.validate_on_submit():
        participant = DemographicData(gender=form.gender.data,
                                      age=form.age.data,
                                      nationality=form.nationality.data)
        session['anonymous_user_id'] = participant.id
        # save to database
        db.session.add(participant)
        db.session.commit()
        return redirect(url_for('megazine')) 
    return render_template('demographics.html', title='Demographic Information', form=form)



# route to a website I want to redirect to after demographics
@app.route("/megazine", methods=['GET', 'POST'])
def megazine():
    if request.method == 'POST':
        consentDecision = ModalData(participant_bref=session['anonymous_user_id'],
                                    consent=request.form['consentForm'])
        db.session.add(consentDecision)
        db.session.commit()
        return redirect(url_for('motivemag'))
    return render_template('/newswebsite_templates/megazine/index.html', title='Megazine')

Answer 1

您想在会话期间或会话后跟踪用户吗？

如果您需要在匿名用户使用您的应用程序期间保留一些数据，您可以轻松地使用 Flask 会话：http://flask.pocoo.org/docs/1.0/api/#flask.session

from flask import session

@app.route('/my_url1')
def my_view1():
    data = None
    if session.new:
         # ... do something like save data in the session
         session['foo'] = 'bar'
    # ... do something like read data in the session
    data = session['foo']
    return render_template('/my_template.html', data=data)

如果你想在会话结束后保留用户的数据，我认为合乎逻辑的做法是动态创建一个用户并记录他。

from flask import session    
from models import User

@app.route('/my_url1')
def my_view1():
    data = None
    if session.new:
         user = User()
         session['anonymous_user_id'] = user.id
    else:
         user = User.query.get(session['anonymous_user_id'])
    # ... do whatever you like

Flask-login - AttributeError: 'AnonymousUserMixin' object has no attribute '_sa_instance_state'

Flask-login - AttributeError: 'AnonymousUserMixin' object has no attribute '_sa_instance_state'

python

flask

anonymous-users