完成登录功能，用session记住用户名

登录功能完成：

1. js:设置return
2. html:设置
   1. form
   2. input

   3. onclick="return fnLogin()"

3. py:
   1. @app.route设置methods
   2. GET
   3. POST
      1. 读取表单数据
      2. 查询数据库
         1. 用户名密码对：
            1. 记住用户名
            2. 跳转到首页
         2. 用户名密码不对：
            1. 提示相应错误。

session：

1. 从`flask`中导入`session`
2. 设置`SECRET_KEY`
3. 操作字典一样操作`session`：增加用户名`session['username']=`username

 

 

 function myLogin() {
        var oUname = document.getElementById("uname");
        var oError = document.getElementById("error_box");
        var opassword = document.getElementById("upass");
        var isError=true;
        oError.innerHTML="<br>";


         if(oUname.value.length<6||oUname.value.length>12){
                oError.innerHTML="number of uname6-12";
                isError=false;
                return isError;
            }
         else if((oUname.value.charCodeAt(0) >= 48) && (oUname.value.charCodeAt(0)<= 57)){
                oError.innerHTML = "first number";
                isError=false;
                return isError;
            }
          else for(var i=0; i<oUname.value.length;i++){
             if((oUname.value.charCodeAt(i)<48||oUname.value.charCodeAt(i)>57)&&(oUname.value.charCodeAt(i)<97||oUname.value.charCodeAt(i)>122)){
               oError.innerHTML="only letter or number";
                isError=false;
                return isError;
             }

             }
         if(opassword.value.length<6||opassword.value.length>12){
                oError.innerHTML="number of password6-12";
                isError=false;
                return isError;
           }
           return isError;
            window.alert("登录成功！")
         }

{% extends 'base.html' %}
{% block title %}登录{% endblock %}

{% block head %}
    <link rel="stylesheet" type="text/css" href="{{ url_for('static',filename='css/login.css') }}">
    <link rel="stylesheet" type="text/css" href="{{ url_for('static',filename='css/base.css') }}">
    <script src="{{url_for('static',filename='js/login.js') }}" type="text/javascript"></script>
{% endblock %}
{% block main %}
    <div class="box">
        <h1>Login</h1>
        <form method="post" action="{{url_for('login')}}">
            <input class="loginInput" type="text" id="uname" placeholder="Uname" required="required" name="username">
            <input class="loginInput" type="password" id="upass" placeholder="password" required="required" name="password">
            <div id="error_box"><br></div>
            <div class="input_box">
                <button onclick="return myLogin()" type="submit" class="btn btn-primary btn-block btn-large">登录</button>
                <br>
                <button onclick=window.alert("是否取消登录！") type="submit" class="btn btn-primary btn-block btn-large"> cancel
                </button>
            </div>
        </form>
    </div>


{% endblock %}

from flask import Flask, render_template, request, redirect, url_for,session
from flask_sqlalchemy import SQLAlchemy
import config

app = Flask(__name__)
app.config.from_object(config)
db = SQLAlchemy(app)


class User(db.Model):
    __table__name = 'user'
    id = db.Column(db.Integer,primary_key=True,autoincrement=True)
    username = db.Column(db.String(20),nullable=False)
    nickname = db.Column(db.String(50))
    password = db.Column(db.String(20),nullable=False)
    phone = db.Column(db.String(20),nullable=False)



#db.create_all()
@app.route('/question/')
def question():
    return render_template('question.html')



@app.route('/')
def index():
    return render_template('index.html')


@app.route('/zhuce/', methods=['GET','POST'])
def zhuce():
    if request.method == 'GET':
        return render_template('zhuce.html')
    else:
        username = request.form.get('username')
        nickname = request.form.get('nickname')
        phone = request.form.get('phone')
        password = request.form.get('password')
        user = User.query.filter(User.username == username).first()
        if user:
            return 'username existed'
        else:
            user = User(username=username, password=password, nickname=nickname, phone=phone)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for('login'))

@app.route('/login/', methods=['GET','POST'])
def login():
    if request.method == 'GET':
        return render_template('login.html')
    else:
        username = request.form.get('username')
        password = request.form.get('password')
        user = User.query.filter(User.username == username).first()
        if user:
            if user.password ==password:
                session['user'] = username
                return redirect(url_for('index'))
            else:
                return u'password error'
        else:
            return u'username is not existed'





if __name__ == '__main__':
    app.run(debug=True)

 用户名存在：

 

密码错误：

 

 登陆成功，跳转首页

import os
SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://root@127.0.0.1:3306/mis_db?charset=utf8'
SQLALCHEMY_TRACK_MODIFICATIONS = False

SECRET_KEY=os.urandom(24)