'current_user.is_authenticated' 的值在模板中始终为 False

Question

如果用户单击登录，我会在主页中为用户创建登录，然后会显示登录页面，如果电子邮件 ID 和密码正确，则用户输入电子邮件 ID 和密码，然后我将用户重定向到主页。现在在主页中，我将登录名替换为用户名并注销。为此，我在模板文件中使用 current_user.is_authenticated 如果它是 true 则显示用户名和注销但它在模板中总是 false 我不知道为什么。我有 config.json 并且我在那里定义了参数，所以不用担心。这是我的 python 代码。

local_server=True

app=Flask(__name__)
app.secret_key='supper-secret-key'

login_manager=LoginManager(app)
login_manager.session_protection="strong"


class Users(UserMixin, db.Model):
    __tablename__='users'
    user_id= db.Column(db.Integer, primary_key=True)
    first_name = db.Column(db.String(80), nullable=False)
    last_name = db.Column(db.String(80), nullable=False)
    email = db.Column(db.String(20), primary_key=True, nullable=False)
    password_hash = db.Column(db.String(80), nullable=False)

    def is_active(self):
        return True
    def is_authenticated(self):
        return self._authenticated
    def is_anonymous(self):
        return False
    def is_admin(self):
        return self.admin
    def __repr__(self):
        return f'<Users:{self.first_name}>'
    def get_id(self):
        return (self.user_id)
    def set_password(self,password):
        self.password_hash = generate_password_hash(password)
    def check_password(self,password):
        return check_password_hash(self.password_hash, password)

@login_manager.user_loader
def load_user(id):
    try:
        return db.session.query(Users).get(id)
    except:
        return None

@app.route("/")
def home():
    return render_template("index.html", params=params)

@app.route("/login", methods=['POST','GET'])
def login_post():
    print("before login",current_user.is_authenticated)    #False
    email=request.form.get('email')
    password = request.form.get('password')
    remember=True if request.form.get('remember') else False
    user=Users.query.filter_by(email=email).first()
    user.check_password(password)
    if not user:
        flash('Please check your login details and try again.', 'danger')
        return redirect(url_for('login'))
    login_user(user,remember=remember,force=True)
    if current_user.is_authenticated:
        print(current_user.first_name)  # user name is properly printed
    flash('Login Successful','success')
    return redirect(url_for('home'))

@app.route("/register")
def register():
    return render_template('register.html',params=params)

@app.route("/register", methods=['GET', 'POST'])
def register_post():
    first_name = request.form.get('fname')
    last_name = request.form.get('lname')
    email = request.form.get('email')
    password= request.form.get('password')
    password2=request.form.get('cpassword')
    if (password!=password2):
        flash('Password must be same','danger')
        return render_template('register.html', params=params)
    users=Users.query.filter_by(email=email).first()
    if users:
        flash('Email address already exists','warning')
        return redirect(url_for('register'))
    new_user=Users(first_name=first_name,last_name=last_name,email=email)
    new_user.set_password(password)
    db.session.add(new_user)
    db.session.commit()
    return redirect(url_for('login'))

@app.route("/logout")
def logout():
    logout_user()
    flash('You were logged out','warning')
    return redirect(url_for('home'))

我认为 python 代码一切正常。这是我的模板文件的代码

{% if current_user.is_authenticated %}     <!-- here current_user.is_authenticted is false -->
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown"
          aria-haspopup="true" aria-expanded="false">
          <img src="static/img/userlogo.png" width="30" height="30" class="rounded-circle" alt="">
          Hey {{ current_user.first_name }}
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdown">
          <a class="dropdown-item" href="#">Profile</a>
      </li>
      <li class="nav-item" style="padding-left: 8px;">
        <a class="btn btn-sm btn-outline-dark" role="button" aria-pressed="true" href="/logout">Logout</a>
      </li>
      {% else %}
      <li class="nav-item" style="padding-left: 8px;">
        <a class="btn btn-sm btn-outline-dark" role="button" aria-pressed="true" href="/login">Login</a>
      </li>
      {% endif %}

请帮我解决这个问题。提前致谢。

Answer 1

在文档中您可以阅读：

To make implementing a user class easier, you can inherit from UserMixin, which provides default implementations for all of these properties and methods.

您继承了 von UserMixin，因此您不需要实现所有这些方法 - 也许这是您的问题。

https://github.com/maxcountryman/flask-login/blob/main/docs/index.rst#your-user-class

例如我的（简化）用户 class 看起来像这样：

class User(db.Model, UserMixin):  # type: ignore
    ...
    def __repr__(self) -> str:
        return f'<User {self.email}>'

根本不需要身份验证助手！

'current_user.is_authenticated' 的值在模板中始终为 False

the value of 'current_user.is_authenticated' is always False in Template

python

authentication

flask

python-3.x

flask-login