经常在各大论坛或新闻板块详情页面下边看到评论功能，当然不单单是直接发表评论内容那么简单，可以对别人的评论进行回复，别人又可以对你的回复再次评论或回复，如此反复，理论上可以说是没有休止，从技术角度分析很容易想到运用无限级分类技术存储数据，运用递归获取评论层级结构数据，运用ajax实现评论页面交互，这里用thinkphp框架做个简单的demo练练手，为了简化流程这里第三级评论开始停止回复，当然只要在这个基础上稍作修改就可以实现无限回复功能，主要是view层样式修改较麻烦，需花些时间。
一、效果需求分析:
1.在头部可以直接发布一级评论,最新发表的评论显示在最上面,如下效果图
2.对发表的评论可以回复，回复显示在上级评论下边，形成层级关系，如下效果图
3.页面操作细节:点击某个评论的回复按钮时，显示回复文本输入框，同时其他评论的回复文本输入框消失，当再次点击该回复按钮时，该文本框消失
4.在最后一级评论(这里设置是第三级)关闭回复功能
5.即时显示评论总数
二、实现思路及细节
1.数据表设计
/**
*递归获取评论列表
*/ protected function getCommlist($parent_id = 0,&$result = array()){
$arr = M('comment')->where("parent_id = '".$parent_id."'")->order("create_time desc")->select();
if(empty($arr)){
return array();
}
foreach ($arr as $cm) {
$thisArr=&$result[];
$cm["children"] = $this->getCommlist($cm["id"],$thisArr);
$thisArr = $cm;
}
return $result;
}
(2). 展示评论页面的action
public function index(){
$num = M('comment')->count(); //获取评论总数
$this->assign('num',$num);
$data=array();
$data=$this->getCommlist();//获取评论列表
$this->assign("commlist",$data);
$this->display('index');
}
(3).评论页面ajax访问添加评论的action
/**
*添加评论
*/ public function addComment(){
$data=array();
if((isset($_POST["comment"]))&&(!empty($_POST["comment"]))){
$cm = json_decode($_POST["comment"],true);//通过第二个参数true，将json字符串转化为键值对数组
$cm['create_time']=date('Y-m-d H:i:s',time());
$newcm = M('comment');
$id = $newcm->add($cm);
$cm["id"] = $id;
$data = $cm;
$num = M('comment')->count();//统计评论总数
$data['num']= $num;
}else{
$data["error"] = "0";
}
echo json_encode($data);
}
3.view层实现
(1). 展示页面的整体结构设计
实际效果:
页面html代码:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" ""> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html;charset=UTF-8"> <title>php无限级分类实战————评论及回复功能</title> <link rel ="stylesheet" type="text/ css " href="/Public/css/comment.css" rel="external nofollow" > <script type="text/javascript" src="/Public/js/jquery-1.11.3.min.js" ></script> <script type="text/javascript" src="/Public/js/comment.js" ></script> </head> <body> <div class="comment-filed"> <!--发表评论区begin--> <div> <div class="comment-num"> <span>{$num}条评论</span> </div> <div> <div> <textarea class="txt-commit" replyid="0"></textarea> </div> <div class="div-txt-submit"> <a class="comment-submit" parent_id="0" style="" href="javascript:%20void (0);" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span style=''>发表评论</span></a> </div> </div> </div> <!--发表评论区end--> <!--评论列表显示区begin--> <!-- {$commentlist} --> <div class="comment-filed-list" > <div><span>全部评论</span></div> <div class="comment-list" > <!--一级评论列表begin--> <ul class="comment-ul"> <volist name="commlist" id="data"> <li comment_id="{$data.id}"> <div > <div> <img class="head-pic" src="{$data.head_pic}" alt=""> </div> <div class="cm"> <div class="cm-header"> <span>{$data.nickname}</span> <span>{$data.create_time}</span> </div> <div class="cm-content"> <p> {$data.content} </p> </div> <div class="cm-footer"> <a class="comment-reply" comment_id="{$data.id}" href="javascript:void(0);" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >回复</a> </div> </div> </div> <!--二级评论begin--> <ul class="children"> <volist name="data.children" id="child" > <li comment_id="{$child.id}"> <div > <div> <img class="head-pic" src="{$child.head_pic}" alt=""> </div> <div class="children-cm"> <div class="cm-header"> <span>{$child.nickname}</span> <span>{$child.create_time}</span> </div> <div class="cm-content"> <p> {$child.content} </p> </div> <div class="cm-footer"> <a class="comment-reply" replyswitch="off" comment_id="{$child.id}" href="javascript:void(0);" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >回复</a> </div> </div> </div> <!--三级评论begin--> <ul class="children"> <volist name="child.children" id="grandson" > <li comment_id="{$grandson.id}"> <div > <div> <img class="head-pic" src="{$grandson.head_pic}" alt=""> </div> <div class="children-cm"> <div class="cm-header"> <span>{$grandson.nickname}</span> <span>{$grandson.create_time}</span> </div> <div class="cm-content"> <p> {$grandson.content} </p> </div> <div class="cm-footer"> <!-- <a class="comment-reply" comment_id="1" href="javascript:void(0);" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >回复</a> --> </div> </div> </div> </li> </volist> </ul> <!--三级评论end--> </li> </volist> </ul> <!--二级评论end--> </li> </volist> </ul> <!--一级评论列表end--> </div> </div> <!--评论列表显示区end--> </div> </body> </html>
(2). 单个评论信息div结构代码
<div >
<div>
<img class="head-pic" src="{$data.head_pic}" alt="">
</div>
<div class="cm">
<div class="cm-header">
<span>{$data.nickname}</span>
<span>{$data.create_time}</span>
</div>
<div class="cm-content">
<p>
{$data.content}
</p>
</div>
<div class="cm-footer">
<a class="comment-reply" comment_id="{$data.id}" href="javascript:void(0);" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >回复</a>
</div>
</div>
</div>
对应的效果图:
对应的css代码:
.head-pic{
width:40px;
height:40px;
}
.cm{
position:relative;
top:0px;
left:40px;
top:-40px;
width:600px;
}
.cm-header{
padding-left:5px;
}
.cm-content{
padding-left:5px;
}
.cm-footer{
padding-bottom:15px;
text-align:right;
border-bottom: 1px dotted #CCC;
}
.comment-reply{
text-decoration :none;
color:gray;
font-size: 14px;
}
4. JS代码
(1). 提交评论:提交评论的a标签按钮引用了样式comment-submit，在其点击事件中进行ajax操作
$('body').delegate('.comment-submit','click',function(){
var content = $.trim($(this).parent().prev().children("textarea").val());//根据布局结构获取当前评论内容
$(this).parent().prev().children("textarea").val("");//获取完内容后清空输入框
if(""==content){
alert("评论内容不能为空!");
}else{
var cmdata = new Object();
cmdata.parent_id = $(this).attr("parent_id");//上级评论id
cmdata.content = content;
cmdata.nickname = "游客";//测试用数据
cmdata.head_pic = "/Public/images/default.jpg";//测试用数据
var replyswitch = $(this).attr("replyswitch");//获取回复开关锁属性
$.ajax({
type:"POST",
url:"/index.php/home/index/addComment",
data:{
comment:JSON.stringify(cmdata)
},
dataType:"json",
success:function(data){
if(typeof(data.error)=="undefined"){
$(".comment-reply").next().remove();//删除已存在的所有回复div
//更新评论总数
$(".comment-num").children("span").html(data.num+"条评论");
//显示新增评论
var newli = "";
if(cmdata.parent_id == "0"){
//发表的是一级评论时，添加到一级ul列表中
newli = "<li comment_id='"+data.id+"'><div ><div><img class='head-pic' src='"+data.head_pic+"' alt=''></div><div class='cm'><div class='cm-header'><span>"+data.nickname+"</span><span>"+data.create_time+"</span></div><div class='cm-content'><p>"+data.content+"</p></div><div class='cm-footer'><a class='comment-reply' comment_id='"+data.id+"' href='javascript:void(0);'>回复</a></div></div></div><ul class='children'></ul></li>";
$(".comment-ul").prepend(newli);
}else{
//否则添加到对应的孩子ul列表中
if('off'==replyswitch){//检验出回复关闭锁存在，即三级评论不再提供回复功能
newli = "<li comment_id='"+data.id+"'><div ><div><img class='head-pic' src='"+data.head_pic+"' alt=''></div><div class='children-cm'><div class='cm-header'><span>"+data.nickname+"</span><span>"+data.create_time+"</span></div><div class='cm-content'><p>"+data.content+"</p></div><div class='cm-footer'></div></div></div><ul class='children'></ul></li>";
}else{//二级评论的回复按钮要添加回复关闭锁属性
newli = "<li comment_id='"+data.id+"'><div ><div><img class='head-pic' src='"+data.head_pic+"' alt=''></div><div class='children-cm'><div class='cm-header'><span>"+data.nickname+"</span><span>"+data.create_time+"</span></div><div class='cm-content'><p>"+data.content+"</p></div><div class='cm-footer'><a class='comment-reply' comment_id='"+data.id+"' href='javascript:void(0);' replyswitch='off' >回复</a></div></div></div><ul class='children'></ul></li>";
}
$("li[comment_id='"+data.parent_id+"']").children("ul").prepend(newli);
}
}else{
//有错误信息
alert(data.error);
}
}
});
}
});
(2).回复评论:回复评论的a标签按钮引用了样式comment-reply，在其点击事件中进行显示或隐藏评论输入框的操作
//点击"回复"按钮显示或隐藏回复输入框
$("body").delegate(".comment-reply","click",function(){
if($(this).next().length>0){//判断出回复div已经存在,去除掉
$(this).next().remove();
}else{//添加回复div
$(".comment-reply").next().remove();//删除已存在的所有回复div
//添加当前回复div
var parent_id = $(this).attr("comment_id");//要回复的评论id
var divhtml = "";
if('off'==$(this).attr("replyswitch")){//二级评论回复后三级评论不再提供回复功能,将关闭属性附加到"提交回复"按钮"
divhtml = "<div class='div-reply-txt' style='width:98%;padding:3px;' replyid='2'><div><textarea class='txt-reply' replyid='2' style='width: 100%; height: 60px;'></textarea></div><div style='margin-top:5px;text-align:right;'><a class='comment-submit' parent_id='"+parent_id+"' style='font-size:14px;text-decoration:none;background-color:#63B8FF;' href='javascript:void(0);' replyswitch='off' >提交回复</a></div></div>";
}else{
divhtml = "<div class='div-reply-txt' style='width:98%;padding:3px;' replyid='2'><div><textarea class='txt-reply' replyid='2' style='width: 100%; height: 60px;'></textarea></div><div style='margin-top:5px;text-align:right;'><a class='comment-submit' parent_id='"+parent_id+"' style='font-size:14px;text-decoration:none;background-color:#63B8FF;' href='javascript:void(0);'>提交回复</a></div></div>";
}
$(this).after(divhtml);
}
});
