PHP使用反向Ajax技术实现在线客服系统详解

?php
setcookie('username','admin');
?>
!DOCTYPE html>
html>
head>
  meta charset="utf-8">
  meta http-equiv="X-UA-Compatible" content="IE=edge">
  title>客服功能——客服人员端/title>
  link rel="stylesheet" href="">
script>
  var xhr = new XMLHttpRequest();
  //服务器调用函数
  function comet(json){
    var content = 'p style="text-align:left">span onclick="choose(\''+ json.pos +'');">' + json.pos + '/span>说：'+json.content+'/p>';
    var old = document.getElementById('chatArea').innerHTML;
    document.getElementById('chatArea').innerHTML = old + content;
  }
  //咨询人选择函数
  function choose(pos){
    document.getElementById('postman').innerHTML = pos;
  }
  //客服人员回复函数
  function resp(){
    var respContent = document.getElementById('respContent').value;
    var pos = document.getElementById('postman').innerHTML;
    if(respContent == '' || pos == ''){
      alert('请重新选择回复人或填写回复内容');
      return;
    }
    //ajax提交请求
    xhr.open('POST','16-kefu-sendmsg.php',true);
    xhr.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
    xhr.onreadystatechange = function (){
      if(this.readyState == 4  this.status == 200){
        if(this.responseText == 'ok'){
          //回复成功，把回复信息显示到聊天界面中
          var content = 'p style="text-align:right">你回复'+ pos + '：'+respContent+'/p>';
          var old = document.getElementById('chatArea').innerHTML;
          document.getElementById('chatArea').innerHTML = old + content;
          document.getElementById('respContent').value = '';//给回复内容重新置空
        }
      }
    }
    var sendData = 'rec=' + pos + 'content='+respContent;
    xhr.send(sendData);
  }  
/script>
style>
  #chatArea{
    width:500px;
    height:400px;
    border:1px solid black;
    overflow: scroll;
  }
/style>
/head>
body>
  h1>客服功能——客服人员端/h1>
  h2>原理：iframe+长连接/h2>
  div id="chatArea">
  /div>
  iframe width="0" height="0" frameborder="0" name="frame" src="./16-kefu-iframe.php">/iframe>
  p>咨询人：span id="postman">/span>/p>
  p>textarea id="respContent">/textarea>/p>
  p>input type="button" value="回复" onclick="resp();" />/p>
/body>
/html>

?php
/**
 * 客服回复咨询人,咨询人咨询客服
 * @author webbc
 */
header('Content-type:text/html;charset=utf-8');
require('./conn.php');
$rec = $_POST['rec'];//咨询人变为接收者
$pos = $_COOKIE['username'];//客服人员变为发送者
$respContent = $_POST['content'];//客服人员的回复内容
$sql = "insert into msg (pos,rec,content) values ('$pos','$rec','$respContent')";
echo mysql_query($sql) ? 'ok':'fail';
?>

?php
/**
 * 通过iframe来实现反向Ajax
 * @author webbc
 */
header('Content-type:text/html;charset=utf-8');
set_time_limit(0);//设置页面永久执行
//ob_start();//打开输出缓存过了，就不需要使用此函数了
//由于浏览器是根据内容大小才先显示，可以先显示4000个空白字符串让浏览器可以继续显示
echo str_repeat(' ', 4000),"br/>";
ob_flush();
flush();
while(true){
  //从数据库读取一条未读的咨询消息
  require('./conn.php');
  $sql = "select * from msg where rec = 'admin' and isread = 0 limit 0,1";
  $result = mysql_query($sql);
  $msg = mysql_fetch_assoc($result);
  //如果有消息
  if(!empty($msg)){
    //设置该消息为已读
    $sql = 'update msg set isread = 1 where mid = '.$msg['mid'];
    mysql_query($sql);
    $json = json_encode($msg);//把数组转换为json数据
    //返回js脚本，影响iframe的父窗体
    echo 'script>';
    echo 'parent.window.comet(',$json,');';
    echo '/script>';
    ob_flush();//强制让php返回给apache
    flush();//强制让web服务器返回给浏览器
  }
  sleep(1);//隔1s循环查1次
}
?>

?php
  setcookie('username','user'.rand(10000,99999));
?>
!DOCTYPE html>
html>
head>
  meta charset="utf-8">
  meta http-equiv="X-UA-Compatible" content="IE=edge">
  title>客服功能——客服人员端/title>
  link rel="stylesheet" href="">
script src="http://libs.baidu.com/jquery/1.7.2/jquery.min.js">/script>
script>
//咨询方法
function ask(){
  var askContent = $('#askContent').val();
  if(askContent == ''){
    alert('请输入咨询内容');
    return ;
  }
  $.post('./16-kefu-sendmsg.php',{rec:'admin',content:askContent},function(res){
    if(res == 'ok'){
      $('p style="text-align:right">你对客服说：'+askContent+'/p>').appendTo($('#chatArea'));
      $('#askContent').val('');
    }
  });
}
/script>
style>
  #chatArea{
    width:500px;
    height:400px;
    border:1px solid black;
    overflow: scroll;
  }
/style>
/head>
body>
  h1>客服功能——用户端/h1>
  h2>原理：ajax+长连接+长轮询/h2>
  div id="chatArea">
  /div>
  p>textarea id="askContent">/textarea>/p>
  p>input type="button" value="咨询" onclick="ask();" />/p>
/body>
script>
  //长连接+长轮询
  var setting = {
    url:'16-kefu-ajax.php',
    dataType:'json',
    success:function(res){
      $('p style="text-align:left">客服对你说：'+res.content+'/p>').appendTo($('#chatArea'));
      var func = function(){$.ajax(setting)};
      window.setTimeout(func,1000);//延时1s后重新发送连接
    }
  }
  $.ajax(setting);
/script>
/html>

?php
/**
 * 通过ajax+长轮询实现反向Ajax
 * @author webbc
 */
set_time_limit(0);//不设置请求超时时间
require('./conn.php');
$rec = $_COOKIE['username'];
$sql = "select * from msg where rec = '$rec' and isread = 0 limit 0,1";
while(true){
  $result = mysql_query($sql);
  $msg = mysql_fetch_assoc($result);
  //如果有客服人员的回复信息
  if(!empty($msg)){
    //把该信息置为已读
    $sql = "update msg set isread = 1 where mid = ".$msg['mid'];
    mysql_query($sql);
    echo json_encode($msg);//返回json数据
    exit();//如果此次连接获取数据，就结束本次连接
  }
  sleep(1);//隔一秒循环1次
}
?>

?php
$conn = mysql_connect('localhost','root','1234');
mysql_query('use test;');
mysql_query('set names utf8');
?>