作业25——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. function fnRegist() {
       var zcoUname = document.getElementById("zcuname")
       var zcoError = document.getElementById("zcerror_box")
       var zcoUword1 = document.getElementById("zcuword1")
       var zcoUword2 = document.getElementById("zcuword2")
       
       zcoError.innerHTML = "<br>"
       if (zcoUname.value.length < 6 || zcoUname.value.length > 12) {
           zcoError.innerHTML = "用户名为6到12位";
           return false
       } else if ((zcoUname.value.charCodeAt(0) >= 48) && (zcoUname.value.charCodeAt(0) <= 57)) {
           zcoError.innerHTML = "用户名首位不能是数字";
           return false
       } else for (var i = 0; i < zcoUname.value.length; i++) {
           if ((zcoUname.value.charCodeAt(i) < 48) || (zcoUname.value.charCodeAt(i) > 57) && (zcoUname.value.charCodeAt(i) < 97) || (zcoUname.value.charCodeAt(i) > 122)) {
               zcoError.innerHTML = "用户名只能是字母与数字";
               return false
           }
       }
       if ((zcoUword1.value.length < 6) || (zcoUword1.value.length > 20)) {
           zcoError.innerHTML = "密码为6到20位";
           return false
       }
       else if (zcoUword2.value.length == 0) {
           zcoError.innerHTML = "请再次输入密码";
           return false
       }
       else if (zcoUword1 != zcoUword2) {
           document.getElementById("error_box").innerHTML = "两次密码不一致"
           return false;
       }
       return true
   }

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

   3. <div class="zcbox">
              <h2 class="zhuce">注册</h2>
              <form action="{{ url_for('regist') }}" method="post">
                  <div class="zcinput_box">
                      <input id="zcuname" type="text" placeholder="请输入用户名" name="username">
                  </div>
                  <div class="zcinput_box">
                      <input id="zcunickname" type="text" placeholder="请输入昵称" name="nickname">
                  </div>
                  <div class="zcinput_box">
                      <input id="zcuword1" type="password" placeholder="请输入密码" name="password">
                  </div>
                  <div class="zcinput_box">
                      <input id="zcuword2" type="password" placeholder="请再次输入密码">
                  </div>
      
                  <div id="zcerror_box"><br></div>
                  <div class="zcinput_box">
                      <button onclick="fnRegist()">立即注册</button>
                  </div>
              </form>
          </div>

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

   3. @app.route('/regist/',methods=['GET','POST'])
      def regist():
          if request.method=='GET':
              return render_template('regist.html')
          else:
              # 获取form中的数据，判断用户名是否存在，存到数据库中
              username=request.form.get('username')
              nickname = request.form.get('nickname')
              password=request.form.get('password')
              user=User.query.filter(User.username==username).first()
              # 重定向到登录页
              if user:
                  return u'用户名已存在'
              else:
                  user=User(username=username,nickname=nickname,password=password)
                  db.session.add(user)
                  db.session.commit()
                  return redirect(url_for('login'))

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

        存到数据库中

        redirect重定向到登录页