前言

使用IDE：PyCharm

操作系统：Mac

Python的版本：3.6

我的邮箱：51263921@qq.com

交流群：372430835

说明：

本次课程的GitHub代码在最下面。

本次课程基于上个课程的代码，如果没看过的请先传送：

使用Python的瓶框架开发的Web网站系列课程（一）构建项目

使用Python的瓶框架开发的Web网站系列课程（二）注册功能

一、登录

本次课程主要实现登录，我们按照实际开发的流程，先看到登录页面，再尝试页面传值（也就是输入账号密码）到服务端，服务端校验和鉴权，并跳转页面。

1.1增加backend.account.views关于登录的代码

全路径：/myproject/backend/account/views.py

#!/usr/bin/python
# -*- coding: UTF-8 -*-
"""
Created by liaoyangyang1 on 2018/8/22 上午9:40.
"""
from flask import Blueprint,request,render_template,jsonify,flash  #第二课增加内容
from backend.models.UserModel import User
from backend.models import db#账户的蓝图  访问http://host:port/account 这个链接的子链接，都会跳到这里
account = Blueprint('/account', __name__)  #第二课增加内容# 访问http://host:port/account/register 这个链接，就会跳到这里
@account.route('/register',methods=(["GET","POST"]))  #第二课增加内容
#上面的链接，绑定的就是这个方法，我们给浏览器或者接口请求 一个json格式的返回
def register():  #第二课增加内容if request.method == 'POST':form = request.formuser = User(username=form['username'],email=form['email'],password=form['password'])db.session.add(user)db.session.commit()return jsonify(form)return render_template('/account/register.html')@account.route('/login',methods=(["GET","POST"]))
def login(): #第三课内容if request.method == "POST":return  jsonify(request.form)return render_template('/account/login.html')

1.2增加html页面文件

全路径:/myproject/frontend/account/login.html

<!DOCTYPE html>
<html>
<head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>INSPINIA | Login</title><link href="https://cdn.bootcss.com/bootstrap/3.3.6/css/bootstrap.css" rel="stylesheet"><link href="https://cdn.bootcss.com/font-awesome/4.3.0/css/font-awesome.css" rel="stylesheet"><link href="https://cdn.bootcss.com/animate.css/3.5.2/animate.css" rel="stylesheet"><link href="../static/css/style.css" rel="stylesheet"></head><body class="gray-bg"><div class="middle-box text-center loginscreen animated fadeInDown"><div><div><h1 class="logo-name">IN+</h1></div><h3>Welcome to IN+</h3><p>Perfectly designed and precisely prepared admin theme with over 50 pages with extra new web app views.<!--Continually expanded and constantly improved Inspinia Admin Them (IN+)--></p><p>Login in. To see it in action.</p><form class="m-t" role="form" action="/account/login" method="post"><div class="form-group"><input type="text" class="form-control" name="username" placeholder="Username" required=""></div><div class="form-group"><input type="password" class="form-control" name="password" placeholder="Password" required=""></div>{% with messages = get_flashed_messages() %}{% if messages %}<div class="alert alert-success">{% for message in messages %}{{ message }}{% endfor %}</div>{% endif %}{% endwith %}<button type="submit" class="btn btn-primary block full-width m-b">Login</button><a href="#"><small>Forgot password?</small></a><p class="text-muted text-center"><small>Do not have an account?</small></p><a class="btn btn-sm btn-white btn-block" href="register.html">Create an account</a></form><p class="m-t"> <small>Inspinia we app framework base on Bootstrap 3 &copy; 2014</small> </p></div></div><!-- Mainly scripts --><script src="https://cdn.bootcss.com/jquery/2.1.1/jquery.js"></script><script src="https://cdn.bootcss.com/bootstrap/3.3.6/js/bootstrap.js"></script></body>
</html>

1.3 测试一把

点击login后显示如下的话，表示成功。{"password": "abc123", "username": "admin"
}

1.4 修改backend.account.view 增加鉴权代码

1.4.1 装个包 pip install Flask-Login==0.4.1

1.4.2 修改 /myproject/backend/view.py 注意修改文件的路径

#!/usr/bin/python
# -*- coding: UTF-8 -*-
"""
Created by liaoyangyang1 on 2018/8/21 下午3:51.
"""
from flask_login import LoginManager  #第三课新增# Set up Flask-Login
login_manager = LoginManager()  #第三课新增
login_manager.session_protection = 'strong'  #第三课新增
login_manager.login_view = 'account.login'  #第三课新增

1.4.3 修改/myproject/backend/__init__.py

#!/usr/bin/python
# -*- coding: UTF-8 -*-
"""
Created by liaoyangyang1 on 2018/8/21 下午2:41.
"""
import os
from flask import Flask
from config.config import config
from backend.urls import register
from backend.models import db  #第二课增加内容
from backend.views import login_manager #第三课增加内容BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
BASE_TEMPLATE_FOLDER = os.path.join(BASE_DIR,'frontend')def create_app():#初始化项目实例app = Flask(__name__,template_folder=BASE_TEMPLATE_FOLDER,static_folder=os.path.join(BASE_DIR,'frontend','static'))app.secret_key = app.config['SECRET_KEY']#导入配置项app.config.from_object(config)# 注册路由register(app)# 注册数据库db.init_app(app) #第二课增加内容#注册登录组件login_manager.init_app(app)  #第三课增加内容# 钩子 在请求执行之前@app.before_requestdef before_request():print('hi')return app

1.4.4 修改/myproject/backend/account/views.py

这里和之前的区别是增加了鉴权的内容，判断用户名和密码是否为空，判断密码对不对。增加了登出的功能。

#!/usr/bin/python
# -*- coding: UTF-8 -*-
"""
Created by liaoyangyang1 on 2018/8/22 上午9:40.
"""
from flask import Blueprint,request,render_template,jsonify,flash  #第二课增加内容
from flask import redirect,url_for,current_app
from backend.models.UserModel import User
from backend.models import db
from flask_login import login_user,login_required,logout_user #第三课增加内容#账户的蓝图  访问http://host:port/account 这个链接的子链接，都会跳到这里
account = Blueprint('account', __name__)  #第二课增加内容# 访问http://host:port/account/register 这个链接，就会跳到这里
@account.route('/register',methods=(["GET","POST"]))  #第二课增加内容
#上面的链接，绑定的就是这个方法，我们给浏览器或者接口请求 一个json格式的返回
def register():  #第二课增加内容if request.method == 'POST':form = request.form user = User(username=form['username'],email=form['email'],password=form['password'])  db.session.add(user)db.session.commit()return jsonify(form)return render_template('/account/register.html')@account.route('/login',methods=(["GET","POST"]))
def login(): #第三课内容if request.method == "POST":form = request.form #获取登录表单user = User.query.filter_by(username=form['username']).first()  #查出用户信息if user is not None and user.password_hash is not None and user.verify_password(form['password']):  #检查密码是否正确login_user(user,True)  #登录操作flash('You are now logged in. Welcome back!', 'success')return redirect( url_for(request.args.get('next') or 'admin.index'))else:flash('Invalid email or password.', 'error')return render_template('/account/login.html')@account.route('/logout')
@login_required
def logout():logout_user()flash('You have been logged out.', 'info')return redirect(url_for('admin.index'))

1.4.5 调整一下我们的/myproject/backend/models/UserModel.py

增加了鉴权模块需要的东西，知识点可以百度flask_login的user_loader和anonymous_user

#!/usr/bin/python
# -*- coding: UTF-8 -*-
"""
Created by liaoyangyang1 on 2018/8/22 下午1:50.
"""
from flask_login import UserMixin,AnonymousUserMixin  #第二课增加内容
from werkzeug.security import check_password_hash, generate_password_hash  #第二课增加内容
from backend.models import db  #第二课增加内容
from backend.views import login_manager #第三课新增class User(UserMixin, db.Model):  #第二课增加内容__tablename__ = 'users'  #这是我们将来建出来的表的表名，在这里定义，下面的都是字段名和字段类型长度这些id = db.Column(db.Integer, primary_key=True)username = db.Column(db.String(64), index=True)email = db.Column(db.String(64), unique=True, index=True)password_hash = db.Column(db.String(128))#脱敏@propertydef password(self):  #第二课增加内容raise AttributeError('`password` is not a readable attribute')#加密@password.setterdef password(self, password):  #第二课增加内容self.password_hash = generate_password_hash(password)#校验密码def verify_password(self, password):  #第二课增加内容return check_password_hash(self.password_hash, password)#查询返回的格式def __repr__(self):  #第二课增加内容return '<User \'%s\'>' % self.usernameclass AnonymousUser(AnonymousUserMixin): #第三课新增def can(self, _):return Falsedef is_admin(self):return Falselogin_manager.anonymous_user = AnonymousUser   #第三课新增@login_manager.user_loader  
def load_user(user_id): #第三课新增return User.query.get(int(user_id))

1.4.6 增加前端目录和页面

先建文件夹

全路径：/myproject/frontend/base

新增页面html文件layout.html

/myproject/frontend/base/layout.html

内容为:

<!doctype html>
<title>My Application</title>
{% with messages = get_flashed_messages() %}{% if messages %}<ul class=flashes>{% for message in messages %}<li>{{ message }}</li>{% endfor %}</ul>{% endif %}
{% endwith %}
{% block body %}{% endblock %}

新增页面html文件index.html

/myproject/frontend/base/index.html

{% extends "base/layout.html" %}
{% block body %}<h1>Overview</h1>{% if current_user.is_authenticated %}<p>welcome ~ <a href="/account/logout">logout</a>{% else %}<p>Do you want to <a href="/account/login">log in?</a>{% endif %}
{% endblock %}

1.4.7 新增后端文件夹和文件

在/myproject/backend/下新增文件夹 admin

全路径: /myproject/backend/admin

在admin下新增__init__.py和views.py

/myproject/backend/admin/__init__.py内容为空

全路径：/myproject/backend/admin/views.py

内容如下：

#!/usr/bin/python
# -*- coding: UTF-8 -*-
"""
Created by liaoyangyang1 on 2018/8/23 上午11:09.
"""
from flask import Blueprint,render_template
from backend.account.views import login_requiredadmin = Blueprint('admin', __name__)@admin.route('/')
def index():return render_template('/base/index.html')