完成注册功能

1.js文件： onclick函数return True时才提交表单，return False时不提交表单。

2.html文件：

1. <form>中设置 action和method="post"
2. <input> 中设置 name

3.主py文件中：

1. from flask import  request, redirect, url_for
2. @app.route('/regist/', methods=['GET', 'POST’])

def regist():

   if request.method == 'GET':

        return render_template('regist.html')

   else:

        username = request.form.get(‘username’)#获取form中的数据

        判断用户名是否存在:存在报错

  不存在，存到数据库中

       redirect重定向到登录页

zhuce.html

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

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

<div class="Outbox">
      <div class="box">
          <h2>欢迎来到博客园，代码改变世界！</h2>
          <h3>用户注册</h3>
          <form method="post" action="{{ url_for('zhuce') }}">
       <div class="input_box">
          输入账号：<input id="name"type="text"placeholder="请输入用户名">name="username"><br>
       </div>
        <div class="input_box">
            输入密码：<input id="password"type="password"placeholder="请输入密码">name="password"><br>
       </div>
          <div class="input_box">
           确认密码：<input id="password1" type="password" placeholder="请再次输入密码">
    </div>
          <div id="error_box"><br></div>
          <div class="input_box">
              <button onclick="myLogin()">注册</button>
<button onclick=window.alert("取消注册") type="submit" class="btn btn-primary btn-block btn-large">返回</button>

          </div>
      </div>

{% endblock %}

 zhece.js

function myLogin(){
            var oUname = document.getElementById("name");
            var oError = document.getElementById("error_box");
             var oUpass = document.getElementById("password");
             var  oUpass1= document.getElementById("password1");
            oError.innerHTML = "<br>"
     //oUname
        if (oUname.value.length>12 || oUname.value.length<6){
            oError.innerHTML = "用户名为6到12位数";
            return false;
         }
         else if((oUname.value.charCodeAt(0)>=48) && oUname.value.charCodeAt(0)<=57){

            oError.innerHTML = "首字母不能是数字";
            return false;
        }
        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 = "只能包含字母和数字";
                    return false;
                }
            }

       if(upass.value.length>12 || upass.value.length<6){
                oError.innerHTML="密码为6到12位数";
                return false;
            }
            if(oUpass.value != oUpass1.value){
                oError.innerHTML="两次密码输入不一致";
                return true;
            }
             window.alert("已成功注册")

        }

 py

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)
    password = db.Column(db.String(20),nullable=False)
    nickname = db.Column(db.String(50))

#db.create_all()



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

@app.route('/login/',methods=['GET','POST'])
def login():
    return render_template('login.html')

@app.route('/zhuce/',methods=['GET','POST'])
def zhuce():
    if request.method =='GET':
        return  render_template('zhuce.html')
    else:
        usern = request.form.get('name')
        teln = request.form.get('password')
        passw = request.form.get('password1')
        user = User.query.filter(User.username==usern).first()
        if user:
            return 'username existed'
        else:
            user= User(username=usern,tel=teln,password=passw)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for('login'))


@app.route('/question/',methods=['GET','POST'])
def question():
    return render_template('question.html')

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