Flask-Login的信号和应用

安装blinker、flask_login

 pip install -i https://pypi.tuna.tsinghua.edu.cn/simple flask_login

 pip install -i https://pypi.tuna.tsinghua.edu.cn/simple blinker 

user_logged_in是signal实例

创建login_manager，继承lask_login.UserMixin的一些属性

app = Flask(__name__)
app.secret_key = 'super secret string'
app.config['SQLALCHEMY_DATABASE_URI'] = SQLALCHEMY_DATABASE_URI
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False


db = SQLAlchemy(app)

login_manager = flask_login.LoginManager()
login_manager.init_app(app)


password = '123'


class User(flask_login.UserMixin, db.Model):
    __tablename__ = 'login_users'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(128), nullable=False)
    login_count = db.Column(db.Integer, default=0)
    last_login_ip = db.Column(db.String(128), default='unknown')


db.create_all()

 

订阅信号

@flask_login.user_logged_in.connect_via(app)#信号订阅user_logged_in.connect(fn)
def _track_logins(sender, user, **extra):
    print("_track_logins")
    user.login_count += 1
    user.last_login_ip = request.remote_addr
    db.session.add(user)
    db.session.commit()

 

发送信号并且记录用户用于后续判断用户状态

@app.route('/login', methods=['GET', 'POST'])
def login():
    print("login")
    if request.method == 'GET':
        return '''
<form action='login' method='POST'>
    <input type='text' name='name' id='name' placeholder='name'></input>
    <input type='password' name='pw' id='pw' placeholder='password'></input>
    <input type='submit' name='submit'></input>
</form>
               '''

    name = request.form.get('name')
    if request.form.get('pw') == password:
        user = User.query.filter_by(name=name).first()
        if not user:
            user = User(name=name)
            db.session.add(user)
            db.session.commit()
        # 信号发送user_logged_in.send
        # 提供给user_loader判断用户是否在登陆状态
        flask_login.login_user(user)
        return redirect(url_for('protected'))

内部实现发送信号的代码：

def login_user(user, remember=False, duration=None, force=False, fresh=True):
    '''
    Logs a user in. You should pass the actual user object to this. If the
    user's `is_active` property is ``False``, they will not be logged in
    unless `force` is ``True``.

    This will return ``True`` if the log in attempt succeeds, and ``False`` if
    it fails (i.e. because the user is inactive).

    :param user: The user object to log in.
    :type user: object
    :param remember: Whether to remember the user after their session expires.
        Defaults to ``False``.
    :type remember: bool
    :param duration: The amount of time before the remember cookie expires. If
        ``None`` the value set in the settings is used. Defaults to ``None``.
    :type duration: :class:`datetime.timedelta`
    :param force: If the user is inactive, setting this to ``True`` will log
        them in regardless. Defaults to ``False``.
    :type force: bool
    :param fresh: setting this to ``False`` will log in the user with a session
        marked as not "fresh". Defaults to ``True``.
    :type fresh: bool
    '''
    if not force and not user.is_active:
        return False

    user_id = getattr(user, current_app.login_manager.id_attribute)()
    session['user_id'] = user_id
    session['_fresh'] = fresh
    session['_id'] = current_app.login_manager._session_identifier_generator()

    if remember:
        session['remember'] = 'set'
        if duration is not None:
            try:
                # equal to timedelta.total_seconds() but works with Python 2.6
                session['remember_seconds'] = (duration.microseconds +
                                               (duration.seconds +
                                                duration.days * 24 * 3600) *
                                               10**6) / 10.0**6
            except AttributeError:
                raise Exception('duration must be a datetime.timedelta, '
                                'instead got: {0}'.format(duration))

    _request_ctx_stack.top.user = user
    user_logged_in.send(current_app._get_current_object(), user=_get_user())
    return True

user_loader根据login_user记录的用户检查相关登陆状态等信息

@login_manager.user_loader
def user_loader(id):
    print("user_loader")
    user = User.query.filter_by(id=id).first()
    return user

完整的代码：

# coding=utf-8
from flask import Flask, request, redirect, url_for
import flask_login
from flask_sqlalchemy import SQLAlchemy

DB_HOSTNAME = 'localhost'
DATABASE_NAME = 'r'
DB_USERNAME = 'web'
DB_PASSWORD = 'web'
DB_PORT = 3306
# 'mysql://{}:{}@{}/{}'.format(
#     USERNAME, PASSWORD, HOSTNAME, DATABASE)
SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://{}:{}@{}:{}/{}?charset=utf8'.format(DB_USERNAME, DB_PASSWORD, DB_HOSTNAME, DB_PORT, DATABASE_NAME)

app = Flask(__name__)
app.secret_key = 'super secret string'
app.config['SQLALCHEMY_DATABASE_URI'] = SQLALCHEMY_DATABASE_URI
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False


db = SQLAlchemy(app)

login_manager = flask_login.LoginManager()
login_manager.init_app(app)


password = '123'


class User(flask_login.UserMixin, db.Model):
    __tablename__ = 'login_users'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(128), nullable=False)
    login_count = db.Column(db.Integer, default=0)
    last_login_ip = db.Column(db.String(128), default='unknown')


db.create_all()


@flask_login.user_logged_in.connect_via(app)#信号订阅user_logged_in.connect(fn)
def _track_logins(sender, user, **extra):
    print("_track_logins")
    user.login_count += 1
    user.last_login_ip = request.remote_addr
    db.session.add(user)
    db.session.commit()


@login_manager.user_loader
def user_loader(id):
    print("user_loader")
    user = User.query.filter_by(id=id).first()
    return user


@app.route('/login', methods=['GET', 'POST'])
def login():
    print("login")
    if request.method == 'GET':
        return '''
<form action='login' method='POST'>
    <input type='text' name='name' id='name' placeholder='name'></input>
    <input type='password' name='pw' id='pw' placeholder='password'></input>
    <input type='submit' name='submit'></input>
</form>
               '''

    name = request.form.get('name')
    if request.form.get('pw') == password:
        user = User.query.filter_by(name=name).first()
        if not user:
            user = User(name=name)
            db.session.add(user)
            db.session.commit()
        # 信号发送user_logged_in.send
        # 提供给user_loader判断用户是否在登陆状态
        flask_login.login_user(user)
        return redirect(url_for('protected'))

    return 'Bad login!'


@app.route('/protected')
@flask_login.login_required
def protected():
    print("protected")
    user = flask_login.current_user
    return 'Logged in as: {}| Login_count: {}|IP: {}'.format(
        user.name, user.login_count, user.last_login_ip)


if __name__ == '__main__':
    app.run(host='0.0.0.0', port=9001, debug=True)