php生成RSS订阅类

下面分享一段使用 php 动态生成 RSS 的代码示例：

/**
** php 动态生成 RSS 类
**/
define("TIME_ZONE","");
define("FEEDCREATOR_VERSION","www.scutephp.com");//您的网址
class FeedItem extends HtmlDescribable{
	var $title,$description,$link;
	var $author,$authorEmail,$image,$category,$comments,$guid,$source,$creator;
	var $date;
	var $additionalElements=Array();
}

class FeedImage extends HtmlDescribable{
	var $title,$url,$link;
	var $width,$height,$description;
}

class HtmlDescribable{
	var $descriptionHtmlSyndicated;
	var $descriptionTruncSize;

	function getDescription(){
		$descriptionField=new FeedHtmlField($this->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)			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.= $indentString."$value$key>\n";
			}
		}
		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) 			$this->_redirect($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 						$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.= "		$feed.= "    xmlns=\"http://purl.org/rss/1.0/\"\n";
		$feed.= "    xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"\n";
		$feed.= "    xmlns:slash=\"http://purl.org/rss/1.0/modules/slash/\"\n";
		$feed.= "    xmlns:dc=\"http://purl.org/dc/elements/1.1/\">\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.= "        Posting\n";
			$feed.= "        text/html\n";
			if($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：

header('Content-Type:text/html; charset=utf-8');
$db=mysql_connect('127.0.0.1','root','123456');
mysql_query("set names utf8");
mysql_select_db('dbname',$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.scutephp.com/';
	$item->description =$rowbrs['description'];
	$rss->addItem($item);
}
mysql_close($db);
$rss->saveFeed("RSS2.0","rss.xml");