在TP框架下使用AJAX验证登陆后台

前台页面

<form id="login"><table align="center"> 
  <tr>  <th>帐号:</th><td><input type="username" name="username"/></td></tr>
  <tr><th>密码:</th><td><input type="password" name="password"/></td></tr>
  <tr><th>验证码:</th><td><input type="code" name="code"/> <img src="{:U('Home/Login/verify', '', '')}" id="code" onclick="javascript:change_code()" /></td></tr>
  <tr><th><input type="reset" class='reset' value="重置" /></th>
     <td> <input type="submit" class="submit" value="登录"/></td>
  </tr>
  <tr><td colspan="2" ><div id="errM"></div></td></tr>
  </table></form>

JS

<script type="text/javascript">var handleUrl = '{:U("Home/Login/handle", "", "")}';</script>

$(function(){
  var username = $("input[name='username']");
  var password = $("input[name='password']");
  var code = $("input[name='code']");
  $("input[type='submit']").click(function(){
      event.preventDefault();//取消默认提交表单
      $.post(
            handleUrl,
            {username:username.val(), password:password.val(), code:code.val()},
            function(data){
                if(data.status == 1){
                    window.location.href = data.url;
                }
                $("#errM").html(data.info);
            }, "json");})
})

TP后台实现

public function handle(){
        if(!IS_AJAX) $this->error("页面不存在。。。");
        $code     = I('code');
        $username = I('username');
        $pwd      = I('password', '', 'md5');
        $data = array(); 
        if ( !$this->checkCode($code) ) {
            //检查验证码是否正确
            $data['info']   = "验证码错误,请检查重试。。。";
            $data['status'] = 0;
            $data['url']    = U('index');
        } else {
            //验证码正确
            $arrUser['username'] = $username;
            $User = M('user')->where($arrUser)->find();
            if( !$User ) {
                //检查用户是否存在
                $data['info']   = "用户不存在，请检查重试。。。";
                $data['status'] = 0;
                $data['url']    = U('index');
            } else {
                //用户存在检查密码是否正确
                if( $pwd != $User['password']) {
                    $data['info']   = "密码错误，请检查重试。。。";
                    $data['status'] = 0;
                    $data['url']    = U('index');
                } else {
                    //登陆通过，把相关内容写入session
                    session('uid',      $User['userid']);
                    session('username', $User['username']);
                    session('role',     $User['role']);
                    $data['info']   = "登陆成功,正在跳转。。。";
                    $data['status'] = 1;
                    $data['url']    = U('Home/Index/index');
                }
            }
      }
      $this->ajaxReturn($data, 'json');
}