搭建 flask 框架

model M


from flask import Flask
from flask_sqlalchemy import SQLAlchemy

import time

# 以下都是套路
app = Flask(__name__)
app.secret_key = 'secret key'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = True
# 指定数据库的路径
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///todos.db'

db = SQLAlchemy(app)


# 定义一个 Model，继承自 db.Model
class Todo(db.Model):
    __tablename__ = 'todos'
    # 下面是字段定义
    id = db.Column(db.Integer, primary_key=True)
    task = db.Column(db.String())
    created_time = db.Column(db.Integer, default=0)

    def __repr__(self):
        return u'<ToDo {} {}>'.format(self.id, self.task)

    def save(self):
        db.session.add(self)
        db.session.commit()

    def delete(self):
        db.session.delete(self)
        db.session.commit()

    def __init__(self, form):
        self.task = form.get('task', '')
        self.created_time = int(time.time())

    def valid(self):
        return len(self.task) > 0


class User(db.Model):
    __tablename__ = 'users'
    # 下面是字段定义
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String())
    password = db.Column(db.String())
    created_time = db.Column(db.Integer, default=0)

    def __repr__(self):
        return u'<User {} {}>'.format(self.id, self.username)

    def save(self):
        db.session.add(self)
        db.session.commit()

    def delete(self):
        db.session.delete(self)
        db.session.commit()

    def __init__(self, form):
        self.username = form.get('username', '')
        self.password = form.get('password', '')
        self.created_time = int(time.time())

    def valid(self):
        return len(self.username) > 2 and len(self.password) > 2

    def validate_login(self, u):
        return u.username == self.username and u.password == self.password

    def change_password(self, password):
        if len(password) > 2:
            self.password = password
            self.save()
            return True
        else:
            return False


if __name__ == '__main__':
    # 先 drop_all 删除所有数据库中的表
    # 再 create_all 创建所有的表
    db.drop_all()
    db.create_all()
    print('rebuild database')

C CONTROLER

from flask import render_template
from flask import request
from flask import redirect
from flask import url_for
from flask import Blueprint
from flask import abort
from flask import session
from models import User


# 创建一个 蓝图对象 并且路由定义在蓝图对象中
# 然后在 flask 主代码中「注册蓝图」来使用
# 第一个参数是蓝图的名字，第二个参数是套路
main = Blueprint('user', __name__)


def current_user():
    uid = session.get('user_id')
    if uid is not None:
        u = User.query.get(uid)
        print('query 速度嫩三', User.query)
        # User.quert就是 user 所有参数,hahah,懂了
        return u


@main.route('/')
def login_view():
    u = current_user()
    if u is not None:
        return redirect('/todo')
    return render_template('user_login.html')


@main.route('/user/register', methods=['POST'])
def register():
    form = request.form
    u = User(form)
    if u.valid():
        u.save()
    else:
        abort(400)
    # 蓝图中的 url_for 需要加上蓝图的名字，这里是 user
    return redirect(url_for('.login_view'))


@main.route('/user/login', methods=['POST'])
def login():
    form = request.form
    u = User(form)
    # 检查 u 是否存在于数据库中并且 密码用户 都验证合格
    user = User.query.filter_by(username=u.username).first()
    if user is not None and user.validate_login(u):
        print('登录成功')
        session['user_id'] = user.id
    else:
        print('登录失败')
    # 蓝图中的 url_for 需要加上蓝图的名字，这里是 user
    return redirect(url_for('.login_view'))


@main.route('/user/update', methods=['POST'])
def update():
    u = current_user()
    password = request.form.get('password', '123')
    if u.change_password(password):
        print('修改成功')
    else:
        print('用户密码修改失败')
    return redirect('/user/profile')


@main.route('/user/profile', methods=['GET'])
def profile():
    u = current_user()
    if u is not None:
        print('profile', u.id, u.username, u.password)
        return render_template('profile.html', user=u)
    else:
        abort(401)

V 可视化

<!DOCTYPE html>
<html lang="en">
<head>
   <meta charset="UTF-8">
   <title>注册与登录</title>
</head>
<body>
   <form action="/user/register" method="post">
       <input name="username">
       <br>
       <input name="password">
       <button>注册</button>
   </form>
   <form action="/user/login" method="post">
       <input name="username">
       <br>
       <input name="password">
       <button>登录</button>
   </form>
</body>
</html>
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