Flask-Login
Flask-Login 提供用户会话管理，处理常见的登录、退出和注册的任务。
Flask-Login 没有绑定数据库,可以从数据库回调用户对象。
安装flask-login
pip install flask-login结构
|-- app/
| |-- __init__.py
| |-- forms.py
| |-- models.py
| |-- routes.py
| `-- templates/
| |-- base.html
| |-- index.html
| |-- login.html
| `-- register.html
|-- app.db
|-- config.py
`-- microblog.py环境变量
安装python-dotenv，避免了每次运行代码都要定义环境变量
pip install python-dotenv根目录新建.flaskenv环境变量文件
.flaskenv：
FLASK_APP=microblog.pymicroblog.py:
from app import app, db
from app.models import User, Post
@app.shell_context_processor
def make_shell_context():
return {'db': db, 'User': User, 'Post': Post}
配置项
import os
basedir = os.path.abspath(os.path.dirname(__file__))
class Config(object):
SECRET_KEY = os.environ.get('SECRET_KEY') or 'you-will-never-guess'
SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL') or \
'sqlite:///' + os.path.join(basedir, 'app.db')
SQLALCHEMY_TRACK_MODIFICATIONS = Falseapp.dp项目运行后产生
初始化模块
app/__init__.py
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate
from config import Config
from flask_login import LoginManager
app = Flask(__name__)
app.config.from_object(Config)
db = SQLAlchemy(app)
migrate = Migrate(app, db)
login = LoginManager(app)
login.login_view = 'login'
from app import routes, models用户加载模块
用户加载模块,完成如下2个功能：
- 定义用户数据库模型
- 加载数据库匹配用户
注意事项：
使用Flask-Login的user类必须实现下列属性方法：
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| 方法 | 含义 |
|---|---|
| is_authenticated | 是登陆用户，返回TRUE；否则False |
| is_active | 是活动用户，返回TRUE；否则False |
| is_anonymous | 是匿名用户，返回TRUE；否则False |
| get_id() | 返回用户唯一标识，用unicode编码，即使是数字类型也要转换成unicode |
如果继承UserMixin类，则默认实现了上述方法；
app/models.py
from datetime import datetime
from app import db, login
from werkzeug.security import generate_password_hash, check_password_hash
from flask_login import UserMixin
class User(UserMixin,db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(64), index=True, unique=True)
email = db.Column(db.String(120), index=True, unique=True)
password_hash = db.Column(db.String(128))
posts = db.relationship('Post', backref='author', lazy='dynamic')
def __repr__(self):
return '<User {}>'.format(self.username)
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.user_loader
def load_user(id):
return User.query.get(int(id))
class Post(db.Model):
id = db.Column(db.Integer, primary_key=True)
body = db.Column(db.String(140))
timestamp = db.Column(db.DateTime, index=True, default=datetime.utcnow)
user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
def __repr__(self):
return '<Post {}>'.format(self.body)
路由和视图函数
- 用户登陆
- 用户注销
- 用户注册
app/routes.py
from flask import render_template, flash, redirect, url_for, request
from flask_login import login_user, logout_user, current_user, login_required
from werkzeug.urls import url_parse
from app import app, db
from app.forms import LoginForm, RegistrationForm
from app.models import User
@app.route('/')
@app.route('/index')
@login_required
def index():
posts = [
{
'author': {'username': 'John'},
'body': 'Beautiful day in Portland!'
},
{
'author': {'username': 'Susan'},
'body': 'The Avengers movie was so cool!'
}
]
return render_template('index.html', title='Home', posts=posts)
@app.route('/login', methods=['GET', 'POST'])
def login():
if current_user.is_authenticated:
return redirect(url_for('index'))
form = LoginForm()
if form.validate_on_submit():
user = User.query.filter_by(username=form.username.data).first()
if user is None or not user.check_password(form.password.data):
flash('Invalid username or password')
return redirect(url_for('login'))
login_user(user, remember=form.remember_me.data)
next_page = request.args.get('next')
if not next_page or url_parse(next_page).netloc != '':
next_page = url_for('index')
return redirect(next_page)
return render_template('login.html', title='Sign In', form=form)
@app.route('/logout')
def logout():
logout_user()
return redirect(url_for('index'))
@app.route('/register', methods=['GET', 'POST'])
def register():
if current_user.is_authenticated:
return redirect(url_for('index'))
form = RegistrationForm()
if form.validate_on_submit():
user = User(username=form.username.data, email=form.email.data)
user.set_password(form.password.data)
db.session.add(user)
db.session.commit()
flash('Congratulations, you are now a registered user!')
return redirect(url_for('login'))
return render_template('register.html', title='Register', form=form)表单
实现2个功能：
- 登陆验证
- 用户注册
app/forms.py：
from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, BooleanField, SubmitField
from wtforms.validators import ValidationError, DataRequired, Email, EqualTo
from app.models import User
class LoginForm(FlaskForm):
username = StringField('Username', validators=[DataRequired()])
password = PasswordField('Password', validators=[DataRequired()])
remember_me = BooleanField('Remember Me')
submit = SubmitField('Sign In')
class RegistrationForm(FlaskForm):
username = StringField('Username', validators=[DataRequired()])
email = StringField('Email', validators=[DataRequired(), Email()])
password = PasswordField('Password', validators=[DataRequired()])
password2 = PasswordField(
'Repeat Password', validators=[DataRequired(), EqualTo('password')])
submit = SubmitField('Register')
def validate_username(self, username):
user = User.query.filter_by(username=username.data).first()
if user is not None:
raise ValidationError('Please use a different username.')
def validate_email(self, email):
user = User.query.filter_by(email=email.data).first()
if user is not None:
raise ValidationError('Please use a different email address.')模板
app/templates/base.html：基本模板，用于做父类提供继承
<html>
<head>
{% if title %}
<title>{{ title }} - Microblog</title>
{% else %}
<title>Welcome to Microblog</title>
{% endif %}
</head>
<body>
<div>
Microblog:
<a href="{{ url_for('index') }}">Home</a>
{% if current_user.is_anonymous %}
<a href="{{ url_for('login') }}">Login</a>
{% else %}
<a href="{{ url_for('logout') }}">Logout</a>
{% endif %}
</div>
<hr>
{% with messages = get_flashed_messages() %}
{% if messages %}
<ul>
{% for message in messages %}
<li>{{ message }}</li>
{% endfor %}
</ul>
{% endif %}
{% endwith %}
{% block content %}{% endblock %}
</body>
</html>app/templates/index.html：起始页面
{% extends "base.html" %}
{% block content %}
<h1>Hi, {{ current_user.username }}!</h1>
{% for post in posts %}
<div><p>{{ post.author.username }} says: <b>{{ post.body }}</b></p></div>
{% endfor %}
{% endblock %}app/templates/register.html：用户注册
{% extends "base.html" %}
{% block content %}
<h1>Register</h1>
<form action="" method="post">
{{ form.hidden_tag() }}
<p>
{{ form.username.label }}<br>
{{ form.username(size=32) }}<br>
{% for error in form.username.errors %}
<span style="color: red;">[{{ error }}]</span>
{% endfor %}
</p>
<p>
{{ form.email.label }}<br>
{{ form.email(size=64) }}<br>
{% for error in form.email.errors %}
<span style="color: red;">[{{ error }}]</span>
{% endfor %}
</p>
<p>
{{ form.password.label }}<br>
{{ form.password(size=32) }}<br>
{% for error in form.password.errors %}
<span style="color: red;">[{{ error }}]</span>
{% endfor %}
</p>
<p>
{{ form.password2.label }}<br>
{{ form.password2(size=32) }}<br>
{% for error in form.password2.errors %}
<span style="color: red;">[{{ error }}]</span>
{% endfor %}
</p>
<p>{{ form.submit() }}</p>
</form>
{% endblock %}app/templates/login.html：游客请登陆
{% extends "base.html" %}
{% block content %}
<h1>Sign In</h1>
<form action="" method="post" novalidate>
{{ form.hidden_tag() }}
<p>
{{ form.username.label }}<br>
{{ form.username(size=32) }}<br>
{% for error in form.username.errors %}
<span style="color: red;">[{{ error }}]</span>
{% endfor %}
</p>
<p>
{{ form.password.label }}<br>
{{ form.password(size=32) }}<br>
{% for error in form.password.errors %}
<span style="color: red;">[{{ error }}]</span>
{% endfor %}
</p>
<p>{{ form.remember_me() }} {{ form.remember_me.label }}</p>
<p>{{ form.submit() }}</p>
</form>
<p>New User? <a href="{{ url_for('register') }}">Click to Register!</a></p>
{% endblock %}项目运行
到项目根目录
PS D:\Days\Flask-Login> flask run
* Serving Flask-SocketIO app "microblog.py"
* Forcing debug mode off
* Serving Flask app "microblog.py"
* Environment: production
WARNING: Do not use the development server in a production environment.
Use a production WSGI server instead.
* Debug mode: off
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
127.0.0.1 - - [30/Nov/2018 11:22:44] "[37mGET /login?next=%2F HTTP/1.1[0m" 200 -浏览器打开：http://localhost:5000
