PHP implements refresh-free login and exit based on Ajax

This article uses Ajax to log in and log out without refreshing, thus improving the user experience. If the user is logged in, the user's relevant login information is displayed, otherwise the login form is displayed.

User login and logout functions are used in many places, and in some projects, we need to use Ajax to log in. After successful login, only part of the page is refreshed, thus improving the user experience. This article will use PHP and jQuery to implement the login and logout functions.

Prepare the database

In this example we use the Mysql database to create a user table with the following table structure:

CREATE TABLE `user` ( 
 `id` int(11) NOT NULL auto_increment, 
 `username` varchar(30) NOT NULL COMMENT '用户名', 
 `password` varchar(32) NOT NULL COMMENT '密码', 
 `login_time` int(10) default NULL COMMENT '登录时间', 
 `login_ip` varchar(32) default NULL COMMENT '登录IP', 
 `login_counts` int(10) NOT NULL default '0' COMMENT '登录次数', 
 PRIMARY KEY (`id`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

Then insert into the user table A piece of user information data:

INSERT INTO `user` (`id`, `username`, `password`, `login_time`, `login_ip`, `login_counts`) 
 VALUES(1, 'demo', 'fe01ce2a7fbac8fafaed7c982a04e229', '', '', 0);

index.php

After the user enters the user name and password, the user is prompted to log in successfully and displays the relevant login information. If the user clicks "Exit ”, then exit to the user login interface.
Enter index.php. If the user is logged in, the login information will be displayed. If the user is not logged in, the login box will be displayed to ask the user to log in.

<p id="login"> 
   <h3 id="用户登录">用户登录</h3> 
   <?php 
   if(isset($_SESSION[&#39;user&#39;])){ 
   ?> 
   <p id="result"> 
    <p><strong><?php echo $_SESSION[&#39;user&#39;];?></strong>，恭喜您登录成功！</p> 
    <p>您这是第<span><?php echo $_SESSION[&#39;login_counts&#39;];?></span>次登录本站。</p> 
    <p>上次登陆本站的时间是：<span><?php echo date(&#39;Y-m-d H:i:s&#39;,$_SESSION[&#39;login_time&#39;]);?> 
</span></p><p><a href=&#39;#&#39; id=&#39;logout&#39;>【退出】</a></p> 
   </p> 
   <?php }else{?> 
   <p id="login_form"> 
     <p><label>用户名：</label> <input type="text" class="input" name="user" id="user" /></p> 
     <p><label>密 码：</label> <input type="password" class="input" name="pass" id="pass" /> 
</p> 
     <p class="sub"> 
       <input type="submit" class="btn" value="登 录" /> 
     </p> 
   </p> 
   <?php }?> 
</p>

Note that the statement should be added to the index.php file header: session_start; At the same time, introduce the jquery library in the head part and include global.js. You can also write a beautiful CSS style for the login box. Of course, this The example has been written in a slightly simple style, please view the source code.

<script type="text/javascript" src="js/jquery.js"></script> 
<script type="text/javascript" src="js/global.js"></script>

global.js

The global.js file includes the jquery code to be implemented. The first thing to do is to let the input box get the focus. As soon as it is opened like Baidu and Google, the mouse cursor will be in the input box. The code used is as follows:

$(function(){ 
  $("#user").focus(); 
});

The next thing to do is to present different styles when the input box gains and loses focus. For example, in this example, different border colors are used. The code is as follows:

$("input:text,textarea,input:password").focus(function() { 
  $(this).addClass("cur_select"); 
}); 
$("input:text,textarea,input:password").blur(function() { 
  $(this).removeClass("cur_select"); 
});

User login: After the user clicks the login button, first verify that the user's input cannot be empty, and then send an Ajax request to the background login.php. When the background verification login is successful, the logged-in user information is returned: such as the number of user logins and the last login time; if the login fails, login failure information is returned.

$(".btn").live('click',function(){ 
  var user = $("#user").val(); 
  var pass = $("#pass").val(); 
  if(user==""){ 
    $(&#39;<p id="msg" />&#39;).html("用户名不能为空！").appendTo(&#39;.sub&#39;).fadeOut(2000); 
    $("#user").focus(); 
    return false; 
  } 
  if(pass==""){ 
    $(&#39;<p id="msg" />&#39;).html("密码不能为空！").appendTo(&#39;.sub&#39;).fadeOut(2000); 
    $("#pass").focus(); 
    return false; 
  } 
  $.ajax({ 
    type: "POST", 
    url: "login.php?action=login", 
    dataType: "json", 
    data: {"user":user,"pass":pass}, 
    beforeSend: function(){ 
      $(&#39;<p id="msg" />&#39;).addClass("loading").html("正在登录...").css("color","#999") 
.appendTo(&#39;.sub&#39;); 
    }, 
    success: function(json){ 
      if(json.success==1){ 
        $("#login_form").remove(); 
        var p = "<p id=&#39;result&#39;><p><strong>"+json.user+"</strong>，恭喜您登录成功！</p> 
        <p>您这是第<span>"+json.login_counts+"</span>次登录本站。</p> 
        <p>上次登录本站的时间是：<span>"+json.login_time+"</span></p><p> 
        <a href=&#39;#&#39; id=&#39;logout&#39;>【退出】</a></p></p>"; 
        $("#login").append(p); 
      }else{ 
        $("#msg").remove(); 
        $(&#39;<p id="errmsg" />&#39;).html(json.msg).css("color","#999").appendTo(&#39;.sub&#39;) 
.fadeOut(2000); 
        return false; 
      } 
    } 
  }); 
});

When I make an Ajax request, the data transmission format is json, and the returned data is also json data. I use JS to parse the json data to get the user information after login, and then append to #login Under the element, complete the login operation.
User exit: When "Exit" is clicked, an Ajax request is sent to login.php, all Sessions are logged out in the background, and the page returns to the login interface.

$("#logout").live('click',function(){ 
  $.post("login.php?action=logout",function(msg){ 
    if(msg==1){ 
       $("#result").remove(); 
       var p = "<p id=&#39;login_form&#39;><p><label>用户名：</label> 
       <input type=&#39;text&#39; class=&#39;input&#39; name=&#39;user&#39; id=&#39;user&#39; /></p> 
       <p><label>密 码：</label> <input type=&#39;password&#39; class=&#39;input&#39; name=&#39;pass&#39; 
id=&#39;pass&#39; /></p> 
       <p class=&#39;sub&#39;><input type=&#39;submit&#39; class=&#39;btn&#39; value=&#39;登 录&#39; /></p> 
       </p>"; 
       $("#login").append(p); 
    } 
  }); 
});

login.php

According to the request submitted by the front desk, when logging in, the user name and password entered by the user are obtained, and compared with the corresponding user name and password in the database Yes, if the comparison is successful, the user's login information will be updated and the json data will be assembled and sent to the front desk.

session_start(); 
require_once ('connect.php'); 
 
$action = $_GET['action']; 
if ($action == 'login') { //登录 
  $user = stripslashes(trim($_POST['user'])); 
  $pass = stripslashes(trim($_POST['pass'])); 
  if (emptyempty ($user)) { 
    echo '用户名不能为空'; 
    exit; 
  } 
  if (emptyempty ($pass)) { 
    echo '密码不能为空'; 
    exit; 
  } 
  $md5pass = md5($pass); //密码使用md5加密 
  $query = mysql_query("select * from user where username='$user'"); 
 
  $us = is_array($row = mysql_fetch_array($query)); 
 
  $ps = $us ? $md5pass == $row['password'] : FALSE; 
  if ($ps) { 
    $counts = $row['login_counts'] + 1; 
    $_SESSION['user'] = $row['username']; 
    $_SESSION['login_time'] = $row['login_time']; 
    $_SESSION['login_counts'] = $counts; 
    $ip = get_client_ip(); //获取登录IP 
    $logintime = mktime(); 
    $rs = mysql_query("update user set login_time='$logintime',login_ip='$ip', 
login_counts='$counts'"); 
    if ($rs) { 
      $arr['success'] = 1; 
      $arr['msg'] = '登录成功！'; 
      $arr['user'] = $_SESSION['user']; 
      $arr['login_time'] = date('Y-m-d H:i:s',$_SESSION['login_time']); 
      $arr['login_counts'] = $_SESSION['login_counts']; 
    } else { 
      $arr['success'] = 0; 
      $arr['msg'] = '登录失败'; 
    } 
  } else { 
    $arr['success'] = 0; 
    $arr['msg'] = '用户名或密码错误！'; 
  } 
  echo json_encode($arr); //输出json数据 
} 
elseif ($action == 'logout') { //退出 
  unset($_SESSION); 
  session_destroy(); 
  echo '1'; 
}

When the front-end request exits, just log out of the session and return 1 to the front-end JS for processing. Note that get_client_ip() in the above code is a function to obtain the client IP. Due to space limitations, it cannot be listed. You can download the source code to view it.

Okay, a complete set of user login and logout procedures is completed. There are inevitable shortcomings. Everyone is welcome to criticize and correct.

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

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