DedeCMS首页列表页AJAX无限加载修正

       最近在学javascript，才慢慢开始读懂JS代码。对HTML前台AJAX加载技术研究了一番，像博客站或者图片站运用AJAX异步无限加载，做成瀑布流，提高用户体验，这是AJAX异步加载的优点。

       AJAX异步加载的弊端：属于WEB前端技术，蜘蛛不会抓JS调用的内容，也就是并不利于SEO优化。所以要运用这个功能的话最好有一部分直接调用，另一部分采用AJAX异步加载。

       接下来用DedeCMS来做AJAX异步加载WEB前端开发。网上有诸多教程，经过笔者整理，给出详细说明，修正后分享给大家。

打开/plus/list.php，找到

require_once(dirname(__FILE__)."/../include/common.inc.php");

下面增加代码

if(isset($_GET['ajax'])){
  $typeid = isset($_GET['typeid']) ? intval($_GET['typeid']): 0;//传递过来的分类ID
  $page = isset($_GET['page']) ? intval($_GET['page']): 0;//页码
  $pagesize = isset($_GET['pagesize']) ? intval($_GET['pagesize']): 15;//每页多少条，也就是一次加载多少条数据
  $start = $page>0 ? ($page-1)*$pagesize : 0;//数据获取的起始位置。即limit条件的第一个参数。
  $typesql = $typeid ? " WHERE typeid=$typeid" : '';//这个是用于首页实现瀑布流加载，因为首页加载数据是无需分类的，所以要加以判断，如果无需
  $total_sql = "SELECT COUNT(id) as num FROM `#分隔符@__archives`  $typesql ";
  $temp = $dsql->GetOne($total_sql);
  $total = 0;//数据总数
  $load_num =0;
  if(is_array($temp)){
    $load_num= round(($temp['num']-15)/$pagesize);//要加载的次数,因为默认已经加载了
    $total = $temp['num'];
  }
  $sql = "SELECT a.*,t.typedir,t.typename,t.isdefault,t.defaultname,t.namerule,
        t.namerule2,t.ispart, t.moresite,t.siteurl,t.sitepath
FROM `#分隔符@__archives` as a JOIN `#分隔符@__arctype` AS t ON a.typeid=t.id    $typesql ORDER BY id DESC LIMIT $start,$pagesize";
//echo "$sql";
   $dsql->SetQuery($sql);
   $dsql->Execute('list');
   $statu = 0;//是否有数据，默认没有数据
   $data = array();
   $index = 0;
while($row = $dsql->GetArray("list")){
   $row['info'] = $row['info'] = $row['infos'] = cn_substr($row['description'],160);
   $row['id'] =  $row['id'];
   $row['filename'] = $row['arcurl'] = GetFileUrl($row['id'],
   $row['typeid'],$row['senddate'],$row['title'],$row['ismake'],
   $row['arcrank'],$row['namerule'],$row['typedir'],$row['money'],
   $row['filename'],$row['moresite'],$row['siteurl'],$row['sitepath']);
   $row['typeurl'] = GetTypeUrl($row['typeid'],$row['typedir'],
   $row['isdefault'],$row['defaultname'],$row['ispart'],
   $row['namerule2'],$row['moresite'],$row['siteurl'],$row['sitepath']);
   if($row['litpic'] == '-' || $row['litpic'] == ''){
    $row['litpic'] = $GLOBALS['cfg_cmspath'].'/images/defaultpic.gif';
   }
   if(!preg_match("#^http:\/\/#i", $row['litpic']) &&$GLOBALS['cfg_multi_site'] == 'Y'){
    $row['litpic'] = $GLOBALS['cfg_mainsite'].$row['litpic'];
   }
   $row['picname'] = $row['litpic'];//缩略图
   $row['stime'] = GetDateMK($row['pubdate']);
   $row['typelink'] = "<a href='".$row['typeurl']."'>".$row['typename']."</a>";//分类链
   $row['fulltitle'] = $row['title'];//完整的标题
   $row['shorttitle'] = $row['shorttitle'];//副标题
   $row['title'] = cn_substr($row['title'], 60);//截取后的标题
   $data[$index] = $row;
   $index++;
}
if(!empty($data)){
$statu = 1;//有数据
}
$result =array('statu'=>$statu,'list'=>$data,'total'=>$total,'load_num'=>$load_num);
echo json_encode($result);//返回数据
exit();
}

       注意上面标红的#分隔符@，使用的时候务必删除“分隔符”三个字。

模板文件增加内容

在需要用AJAX异步加载的模板的</head>前增加代码

<script src="http://libs.baidu.com/jquery/1.9.0/jquery.js"></script>
<script type="text/javascript">
var loadConfig = {
        url_api:'{dede:global.cfg_cmspath/}/plus/list.php', //修正plus目录
        typeid:{dede:field name='typeid'/}, //首页此处是typeid:0,
        page:2,
        pagesize:3,
        loading : 0,
        }
function  loadMoreApply(){
  if(loadConfig.loading == 0){
     var typeid = loadConfig.typeid;
     var page = loadConfig.page;
     var pagesize = loadConfig.pagesize;
     var url = loadConfig.url_api,data={ajax:'pullload',typeid:typeid,page:page,pagesize:pagesize};
     var sTop = document.body.scrollTop || document.documentElement.scrollTop, dHeight = $(document).height(), cHeight = document.documentElement.clientHeight;
     console.log(dHeight);
         if (sTop + cHeight >= dHeight - cHeight) {
       loadConfig.loading = 1;
      function ajax(url, data) {
        $.ajax({url: url,data: data,async: false,type: 'GET',dataType: 'json',success: function(data) {
          addContent(data); 
        }});
      }
     ajax(url,data);
    }
  }
}
 function addContent (rs){
  if(rs.statu== 1){
    var data = rs.list;
    var total = rs.total;
    var arr=[];
    var length = data.length;
    for(var i=0;i<length;i++){
      arr.push('<li>');
      arr.push('<a href="'+data[i].arcurl+'" class="preview">');
      arr.push('<img class="" width="" height="" alt="data[i].title" src="'+data[i].picname+'" />');
      arr.push('</a>');
      arr.push('[<b>'+data[i].typelink+'</b>]');
      arr.push('<a href="'+data[i].arcurl+'" class="title">'+data[i].title+'</a>');
      arr.push('</li>');          
    }
    $('.data-list').append(arr.join(''));
    loadConfig.load_num = rs.load_num;
    if(total<loadConfig.page*loadConfig.pagesize || loadConfig.page > loadConfig.load_num){
      window.removeEventListener('srcoll',loadMoreApply,false);
    }
    loadConfig.page++;
    loadConfig.loading = 0;
  }
}
function pullLoad(){
  window.addEventListener('scroll', loadMoreApply, false);
}
pullLoad();
</script>

首页HTML代码示例

<p class="listbox">
 <ul class="e2">
  <p class="data-list">
  {dede:arclist row='3'}
   <li> [field:array runphp='yes']@me = (empty(@me['litpic']) ? "" : "<a href='{@me['arcurl']}' class='preview'><img src='{@me['litpic']}'/></a>"); [/field:array]
     [<b>[field:typelink/]</b>] <a href="[field:arcurl/]" class="title">[field:title/]</a> <span class="info"> <small>日期：</small>[field:pubdate function="GetDateTimeMK(@me)"/] <small>点击：</small>[field:click/] <small>好评：</small>[field:scores/] </span>
    <p class="intro"> [field:description/]... </p>
   </li>
  {/dede:arclist}
  </p><!--data-list-->
 </ul>
</p>
<!-- /listbox -->

       注意：首页模板用arclist标签，用row='3'是初始化调用的3条；列表模板用list标签，用pagesize='3'。模板里面的<p class="data-list“>与js里面的data-list对应，需要把循环部分全部包裹起来。