完成登录功能，用session记住用户名v

登录功能完成：

1. js:设置return
2. html:设置
   1. form
   2. input
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 foLogin() {
            var oUname = document.getElementById("uname");
            var oError = document.getElementById("error_box");
            var oUpass = document.getElementById("upass");

            var isError = true;
            oError.innerHTML = "<br>";

            if (oUname.value.length < 6 || oUname.value.length > 12) {
                oError.innerHTML = "用户名要6-12位";
                isError = false;
                return;
            }else if(oUname.value.charCodeAt(0)>=48 &&(oUname.value.charCodeAt(0)<=57)){
                oError.innerHTML="首位不能为数字";
                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)<58)&&(oUname.value.charCodeAt(i)>97)){
                oError.innerHTML="只能为数字和字母";
                isError = false;
                return isError;
            }
            }
            if (oUpass.value.length < 6 || oUpass.value.length > 12) {
                oError.innerHTML = "密码要6-20位";
                isError = false;
                isError = false;
                return isError;
             }
            return ture;
            }

　　

{% extends'index.html' %}

{% block title %}登录 {% endblock %}

{% block head %}
 <link rel="stylesheet" type="text/css" href="{{ url_for('static',filename='css/886.css') }}">
    <script src="{{ url_for('static',filename='js/tt.js')}}"></script>
{% endblock %}

{% block main %}
 <div class="box">
         <h2 class="dd">登录</h2>
         <form action="{{url_for('login')}}" method="post">
         <div class="input_box">
             <input id="uname" type="text" placeholder="请输入用户名" name="username">
         </div>
         <div class="input_box">
             <input id="upass" type="password" placeholder="请输入密码" name="password">
         </div>
         <div id="error_box"><br></div>
         <div>
             <button class="jj" onclick="fnLogin()">登录</button>
        </div>
         </form>
     </div>
{% endblock %}

　　

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


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

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


# db.create_all()
# 增加
# user = User(username='mis1114',password = 'mis1114',nickname='mis1114')
# db.session.add(user)
# db.session.commit()
# # 查询
# User.query.filter(User.username == 'mis1114').first()
# #修改
# user =User.query.filter(User.username =='mis1114').first()
# user.password='23456'
# print(user.username,user.password)
# db.session.commit()
# # 删除
# user =User.query.filter(User.username =='mis1114').first()
# db.session.delete(user)
# db.session.commit()


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

@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,User.password==password).first()
        if user:
            session['user']=username
            session.permanent=True
            return redirect(url_for('index'))
        else:
            return u'error username or password'


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

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

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