PHP生成RSS订阅的程序代码

rss（简易信息聚合也叫聚合内容）是一种描述和同步网站内容的格式。下面的生成RSS订阅的代码：
rss XML结构

http://www.111com.net/
网站描述!


网站地址/rss
New RSS tutorial on W3School



网站地址/xml
New XML tutorial on W3School

RSS实例

'.$webUrl.'
'.$webDesc.'
'.$this->createItem().'


';
echo $html;
}
private function createItem() {
//RSS item
//$data可替换为自己的数据
$html = '';
//文章数据
$data = array(
'id' => 1,
'date' => date('r', time()),
'title' => '文章标题',
'link' => 'http://www.111com.net',    //文章地址
'description' => '网站描述'
);
for($i = 0; $i < 6; $i++) {
$html .= '


'.$data['link'].'
'.$data['date'].'


';
}
return $html;
}
}
header("Content-Type: text/xml; charset=utf-8");
$rss = new Rss();
$rss->createFeed();
exit;
?>

RSS Feed 生成后，如何设置才能给网站添加 RSS 呢？并且让 Firefox、IE7 或其它 Feed 机器人自动发现？很简单，在网页的 Head 节添加一个特定的 Link 标签即可，如下：

设置 title 为 Feed 标题，href 为 Feed 地址，一切就 OK 了！

例子2

http://www.111com.net/

本站是一个php程序员的工作生活笔记!





网站地址/rss

New RSS tutorial on W3School







网站地址/xml

New XML tutorial on W3School

下面分享一段使用 php 动态生成 RSS 的代码示例：

description);
  $descriptionField->syndicateHtml=$this->descriptionHtmlSyndicated;
  $descriptionField->truncSize=$this->descriptionTruncSize;
  return $descriptionField->output();
 }
}
class FeedHtmlField{
 var $rawFieldContent;
 var $truncSize,$syndicateHtml;
 function FeedHtmlField($parFieldContent){
  if($parFieldContent){
   $this->rawFieldContent=$parFieldContent;
  }
 }
 function output(){
  if(!$this->rawFieldContent){
   $result="";
  }    elseif($this->syndicateHtml){
   $result="rawFieldContent."]]>";
  }else{
   if($this->truncSize and is_int($this->truncSize)){
    $result=FeedCreator::iTrunc(htmlspecialchars($this->rawFieldContent),$this->truncSize);
   }else{
    $result=htmlspecialchars($this->rawFieldContent);
   }
  }
  return $result;
 }
}
class UniversalFeedCreator extends FeedCreator{
 var $_feed;
 function _setFormat($format){
  switch (strtoupper($format)){
   case "2.0":
    // fall through
   case "RSS2.0":
    $this->_feed=new RSSCreator20();
    break;
   case "0.91":
    // fall through
   case "RSS0.91":
    $this->_feed=new RSSCreator091();
    break;
   default:
    $this->_feed=new RSSCreator091();
    break;
  }
  $vars=get_object_vars($this);
  foreach ($vars as $key => $value){
   // prevent overwriting of properties "contentType","encoding"; do not copy "_feed" itself
   if(!in_array($key, array("_feed","contentType","encoding"))){
    $this->_feed->{$key}=$this->{$key};
   }
  }
 }
 function createFeed($format="RSS0.91"){
  $this->_setFormat($format);
  return $this->_feed->createFeed();
 }
 function saveFeed($format="RSS0.91",$filename="",$displayContents=true){
  $this->_setFormat($format);
  $this->_feed->saveFeed($filename,$displayContents);
 }
 function useCached($format="RSS0.91",$filename="",$timeout=3600){
  $this->_setFormat($format);
  $this->_feed->useCached($filename,$timeout);
 }
}
class FeedCreator extends HtmlDescribable{
 var $title,$description,$link;
 var $syndicationURL,$image,$language,$copyright,$pubDate,$lastBuildDate,$editor,$editorEmail,$webmaster,$category,$docs,$ttl,$rating,$skipHours,$skipDays;
 var $xslStyleSheet="";
 var $items=Array();
 var $contentType="application/xml";
 var $encoding="utf-8";
 var $additionalElements=Array();
 function addItem($item){
  $this->items[]=$item;
 }
 function clearItem2Null(){
  $this->items=array();
 }
 function iTrunc($string,$length){
  if(strlen($string)<=$length){
   return $string;
  }
  $pos=strrpos($string,".");
  if($pos>=$length-4){
   $string=substr($string,0,$length-4);
   $pos=strrpos($string,".");
  }
  if($pos>=$length*0.4){
   return substr($string,0,$pos+1)." ...";
  }
  $pos=strrpos($string," ");
  if($pos>=$length-4){
   $string=substr($string,0,$length-4);
   $pos=strrpos($string," ");
  }
  if($pos>=$length*0.4){
   return substr($string,0,$pos)." ...";
  }
  return substr($string,0,$length-4)." ...";
 }

 function _createGeneratorComment(){
  return "n";
 }
 function _createAdditionalElements($elements,$indentString=""){
  $ae="";
  if(is_array($elements)){
   foreach($elements AS $key => $value){
    $ae.= $indentString."<$key>$valuen";
   }
  }
  return $ae;
 }
 function _createStylesheetReferences(){
  $xml="";
  if($this->cssStyleSheet) $xml .= "cssStyleSheet."" type="text/css"?>n";
  if($this->xslStyleSheet) $xml .= "xslStyleSheet."" type="text/xsl"?>n";
  return $xml;
 }
 function createFeed(){}
 function _generateFilename(){
  $fileInfo=pathinfo($_SERVER["PHP_SELF"]);
  return substr($fileInfo["basename"],0,-(strlen($fileInfo["extension"])+1)).".xml";
 }
 function _redirect($filename){
  Header("Content-Type: ".$this->contentType."; charset=".$this->encoding."; filename=".basename($filename));
  Header("Content-Disposition: inline; filename=".basename($filename));
  readfile($filename,"r");
  die();
 }
 function useCached($filename="",$timeout=3600){
  $this->_timeout=$timeout;
  if($filename==""){
   $filename=$this->_generateFilename();
  }
  if(file_exists($filename) && (time()-filemtime($filename) < $timeout)){
   $this->_redirect($filename);
  }
 }
 function saveFeed($filename="",$displayContents=true){
  if($filename==""){
   $filename=$this->_generateFilename();
  }
  $feedFile=fopen($filename,"w+");
  if($feedFile){
   fputs($feedFile,$this->createFeed());
   fclose($feedFile);
   if($displayContents){
    $this->_redirect($filename);
   }
  }else{
   echo "Error creating feed file, please check write permissions.";
  }
 }
}
class FeedDate{
 var $unix;
 function FeedDate($dateString=""){
  if($dateString=="") $dateString=date("r");
  if(is_integer($dateString)){
   $this->unix=$dateString;
   return;
  }
  if(preg_match("~(?:(?:Mon|Tue|Wed|Thu|Fri|Sat|Sun),\s+)?(\d{1,2})\s+([a-zA-Z]{3})\s+(\d{4})\s+(\d{2}):(\d{2}):(\d{2})\s+(.*)~",$dateString,$matches)){
   $months=Array("Jan"=>1,"Feb"=>2,"Mar"=>3,"Apr"=>4,"May"=>5,"Jun"=>6,"Jul"=>7,"Aug"=>8,"Sep"=>9,"Oct"=>10,"Nov"=>11,"Dec"=>12);
   $this->unix=mktime($matches[4],$matches[5],$matches[6],$months[$matches[2]],$matches[1],$matches[3]);
   if(substr($matches[7],0,1)=='+' OR substr($matches[7],0,1)=='-'){
    $tzOffset=(substr($matches[7],0,3) * 60 + substr($matches[7],-2)) * 60;
   }else{
    if(strlen($matches[7])==1){
     $oneHour=3600;
     $ord=ord($matches[7]);
     if($ord < ord("M")){
      $tzOffset=(ord("A") - $ord - 1) * $oneHour;
     } elseif($ord >= ord("M") && $matches[7]!="Z"){
      $tzOffset=($ord - ord("M")) * $oneHour;
     } elseif($matches[7]=="Z"){
      $tzOffset=0;
     }
    }
    switch ($matches[7]){
     case "UT":
     case "GMT":    $tzOffset=0;
    }
   }
   $this->unix += $tzOffset;
   return;
  }
  if(preg_match("~(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(.*)~",$dateString,$matches)){
   $this->unix=mktime($matches[4],$matches[5],$matches[6],$matches[2],$matches[3],$matches[1]);
   if(substr($matches[7],0,1)=='+' OR substr($matches[7],0,1)=='-'){
    $tzOffset=(substr($matches[7],0,3) * 60 + substr($matches[7],-2)) * 60;
   }else{
    if($matches[7]=="Z"){
     $tzOffset=0;
    }
   }
   $this->unix += $tzOffset;
   return;
  }
  $this->unix=0;
 }
 function rfc822(){
  $date=gmdate("Y-m-d H:i:s",$this->unix);
  if(TIME_ZONE!="") $date .= " ".str_replace(":","",TIME_ZONE);
  return $date;
 }
 function iso8601(){
  $date=gmdate("Y-m-d H:i:s",$this->unix);
  $date=substr($date,0,22) . ':' . substr($date,-2);
  if(TIME_ZONE!="") $date=str_replace("+00:00",TIME_ZONE,$date);
  return $date;
 }
 function unix(){
  return $this->unix;
 }
}
class RSSCreator10 extends FeedCreator{
 function createFeed(){
  $feed="encoding.""?>n";
  $feed.= $this->_createGeneratorComment();
  if($this->cssStyleSheet==""){
   $cssStyleSheet="http://www.w3.org/2000/08/w3c-synd/style.css";
  }
  $feed.= $this->_createStylesheetReferences();
  $feed.= "n";
  $feed.= "    syndicationURL."">n";
  $feed.= "        n";
  $feed.= "        ".htmlspecialchars($this->description)."n";
  $feed.= "        ".$this->link."n";
  if($this->image!=null){
   $feed.= "        image->url."" />n";
  }
  $now=new FeedDate();
  $feed.= "       ".htmlspecialchars($now->iso8601())."n";
  $feed.= "        n";
  $feed.= "            n";
  for ($i=0;$iitems);$i++){
   $feed.= "                items[$i]->link).""/>n";
  }
  $feed.= "            n";
  $feed.= "        n";
  $feed.= "    n";
  if($this->image!=null){
   $feed.= "    image->url."">n";
   $feed.= "        n";
   $feed.= "        ".$this->image->link."n";
   $feed.= "        ".$this->image->url."n";
   $feed.= "    n";
  }
  $feed.= $this->_createAdditionalElements($this->additionalElements,"    ");
  for ($i=0;$iitems);$i++){
   $feed.= "    items[$i]->link)."">n";
   //$feed.= "        Postingn";
   $feed.= "        text/htmln";
   if($this->items[$i]->date!=null){
    $itemDate=new FeedDate($this->items[$i]->date);
    $feed.= "        ".htmlspecialchars($itemDate->iso8601())."n";
   }
   if($this->items[$i]->source!=""){
    $feed.= "        ".htmlspecialchars($this->items[$i]->source)."n";
   }
   if($this->items[$i]->author!=""){
    $feed.= "        ".htmlspecialchars($this->items[$i]->author)."n";
   }
   $feed.= "        n";
   $feed.= "        ".htmlspecialchars($this->items[$i]->link)."n";
   $feed.= "        ".htmlspecialchars($this->items[$i]->description)."n";
   $feed.= $this->_createAdditionalElements($this->items[$i]->additionalElements,"        ");
   $feed.= "    n";
  }
  $feed.= "n";
  return $feed;
 }
}
class RSSCreator091 extends FeedCreator{
 var $RSSVersion;
 function RSSCreator091(){
  $this->_setRSSVersion("0.91");
  $this->contentType="application/rss+xml";
 }
 function _setRSSVersion($version){
  $this->RSSVersion=$version;
 }
 function createFeed(){
  $feed="encoding.""?>n";
  $feed.= $this->_createGeneratorComment();
  $feed.= $this->_createStylesheetReferences();
  $feed.= "RSSVersion."">n";
  $feed.= "    n";
  $feed.= "        n";
  $this->descriptionTruncSize=500;
  $feed.= "        ".$this->getDescription()."n";
  $feed.= "        ".$this->link."n";
  $now=new FeedDate();
  $feed.= "        ".htmlspecialchars($now->rfc822())."n";
  $feed.= "        ".FEEDCREATOR_VERSION."n";
  if($this->image!=null){
   $feed.= "        n";
   $feed.= "            ".$this->image->url."n";
   $feed.= "            n";
   $feed.= "            ".$this->image->link."n";
   if($this->image->width!=""){
    $feed.= "            ".$this->image->width."n";
   }
   if($this->image->height!=""){
    $feed.= "            ".$this->image->height."n";
   }
   if($this->image->description!=""){
    $feed.= "            ".$this->image->getDescription()."n";
   }
   $feed.= "        n";
  }
  if($this->language!=""){
   $feed.= "        ".$this->language."n";
  }
  if($this->copyright!=""){
   $feed.= "        ".FeedCreator::iTrunc(htmlspecialchars($this->copyright),100)."n";
  }
  if($this->editor!=""){
   $feed.= "        ".FeedCreator::iTrunc(htmlspecialchars($this->editor),100)."n";
  }
  if($this->webmaster!=""){
   $feed.= "        ".FeedCreator::iTrunc(htmlspecialchars($this->webmaster),100)."n";
  }
  if($this->pubDate!=""){
   $pubDate=new FeedDate($this->pubDate);
   $feed.= "        ".htmlspecialchars($pubDate->rfc822())."n";
  }
  if($this->category!=""){
   $feed.= "        ".htmlspecialchars($this->category)."n";
  }
  if($this->docs!=""){
   $feed.= "        ".FeedCreator::iTrunc(htmlspecialchars($this->docs),500)."n";
  }
  if($this->ttl!=""){
   $feed.= "        ".htmlspecialchars($this->ttl)."n";
  }
  if($this->rating!=""){
   $feed.= "        ".FeedCreator::iTrunc(htmlspecialchars($this->rating),500)."n";
  }
  if($this->skipHours!=""){
   $feed.= "        ".htmlspecialchars($this->skipHours)."n";
  }
  if($this->skipDays!=""){
   $feed.= "        ".htmlspecialchars($this->skipDays)."n";
  }
  $feed.= $this->_createAdditionalElements($this->additionalElements,"    ");
  for ($i=0;$iitems);$i++){
   $feed.= "        n";
   $feed.= "            n";
   $feed.= "            ".htmlspecialchars($this->items[$i]->link)."n";
   $feed.= "            ".$this->items[$i]->getDescription()."n";
   if($this->items[$i]->author!=""){
    $feed.= "            ".htmlspecialchars($this->items[$i]->author)."n";
   }
   /*
    // on hold
    if($this->items[$i]->source!=""){
    $feed.= "            ".htmlspecialchars($this->items[$i]->source)."n";
    }
    */
   if($this->items[$i]->category!=""){
    $feed.= "            ".htmlspecialchars($this->items[$i]->category)."n";
   }
   if($this->items[$i]->comments!=""){
    $feed.= "            ".htmlspecialchars($this->items[$i]->comments)."n";
   }
   if($this->items[$i]->date!=""){
    $itemDate=new FeedDate($this->items[$i]->date);
    $feed.= "            ".htmlspecialchars($itemDate->rfc822())."n";
   }
   if($this->items[$i]->guid!=""){
    $feed.= "            ".htmlspecialchars($this->items[$i]->guid)."n";
   }
   $feed.= $this->_createAdditionalElements($this->items[$i]->additionalElements,"        ");
   $feed.= "        n";
  }
  $feed.= "    n";
  $feed.= "n";
  return $feed;
 }
}
class RSSCreator20 extends RSSCreator091{
 function RSSCreator20(){
  parent::_setRSSVersion("2.0");
 }
}

使用示例：

select_db('dbname',$db);
$brs=mysql_query('select * from article order by add_time desc limit 0,10',$db);
$rss=new UniversalFeedCreator();
$rss->title="页面标题";
$rss->link="网址http://";
$rss->description="rss标题";
while($rowbrs=mysql_fetch_array($brs)){
 $item=new FeedItem();
 $item->title =$rowbrs['subject'];
 $item->link='http://www.111com.net/';
 $item->description =$rowbrs['description'];
 $rss->addItem($item);
}
mysql_close($db);
$rss->saveFeed("RSS2.0","rss.xml");