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。

   function fnLogin() {
       var oUname = document.getElementById("uname");
       var oError = document.getElementById("error_box");
       var oUpass = document.getElementById("upass");
       var oCheckpass = document.getElementById("checkpass");
       oError.innerHTML="<br>";
   
       if(oUname.value.length<6||oUname.value.length>20){
           oError.innerHTML="用户名长度为6到12位";
           return false;
       }else if(oUname.value.charCodeAt(0)>=48&&oUname.value.charCodeAt(0)<=57){
           oError.innerHTML="用户名不能以数字开头";
           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="用户名只能包含数字，小写字母";
           return false;
           }
       }
   
       if(oUpass.value.length<6||oUpass.value.length>20){
           oError.innerHTML="密码长度为6-12位";
           return false;
       }
   
       if(oCheckpass.value!=oUpass.value){
           oError.innerHTML="密码不一致" ;
           return false;
       }else if(oCheckpass.value==""){
           oError.innerHTML="未确认密码";
           return false;
       }
   
       window.alert("注册成功");
       return true;
   }

    

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

      {% extends 'index.html' %}
      
      {% block zhucetitle %}注册{% endblock %}
      {% block zhucehead %}
          <link rel="stylesheet" type="text/css" href="{{ url_for('static',filename='css/login.css') }}">
          <script src="{{ url_for('static',filename='js/login.js') }}"></script>
      {% endblock %}
      {% block zhucebody %}
          <div id="container" style="margin-left: auto;margin-right: auto">
              <div id="header"><h2 align="center">注册</h2></div>
              <div id="content">
                  <form action="{{ url_for('zhuce') }}" method="post">
                      <p align="center">Username：</p>
                      <p align="center">
                          <input type="text" name="username" id="user" placeholder="请输入用户名">
                      </p>
                      <p align="center">Password：</p>
                      <p align="center">
                          <input type="password" name="password" id="pass" placeholder="请输入密码">
                      </p>
                      <p align="center">Lnput again：</p>
                      <p align="center">
                          <input type="password" name="again" id="again" placeholder="再次输入密码">
                      </p>
                      <p align="center">
                          <input type="radio" name="r1" id="r1" value="stu">student
                          <input type="radio" name="r2" id="r2" value="tea">teacher
                      </p>
                      <div id="error_box"><br></div>
                      <p align="center">
                          <button onclick="return zhuce()">注册</button>
                      </p>
      
                  </form>
              </div>
              <div id="footer"><p align="right">版权@misaki</p></div>
          </div>
      {% endblock %}

       

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

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

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)

    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('username')
        passw=request.form.get('password')
        user=User.query.filter(User.username==usern).first()
        if user:
            return u'user existed'
        else:
            user1=User(username=usern,password=passw)
            db.session.add(user1)
            db.session.commit()
            return redirect(url_for('login'))


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