首页 > php教程 > php手册 > php生成RSS订阅的方法,phprss订阅

php生成RSS订阅的方法,phprss订阅

WBOY
发布: 2016-06-13 09:14:35
原创
1016 人浏览过

php生成RSS订阅的方法,phprss订阅

本文实例讲述了php生成RSS订阅的方法。分享给大家供大家参考。具体分析如下:

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。RSS可以是以下三个解释的其中一个: Really Simple Syndication;RDF (Resource Description Framework) Site Summary; Rich Site Summary。但其实这三个解释都是指同一种Syndication的技术。RSS目前广泛用于网上新闻频道,blog和wiki。使用RSS订阅能更快地获取信息,网站提供RSS输出,有利于让用户获取网站内容的最新更新。网络用户可以在客户端借助于支持RSS的聚合工具软件,在不打开网站内容页面的情况下阅读支持RSS输出的网站内容。
从技术上来说一个RSS文件就是一段规范的XML数据,该文件一般以rss,xml或者rdf作为后缀,下面是一段 rss 文件的内容示例:

复制代码 代码如下:




帮客之家
http://www.bkjia.com/
帮客之家

RSS Tutorial
网站地址/rss
New RSS tutorial on W3School


XML Tutorial
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:

复制代码 代码如下:

/**
** php 动态生成 RSS 类
**/
define("TIME_ZONE","");
define("FEEDCREATOR_VERSION","www.jb51.net");//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";
        $feed.= "        ".htmlspecialchars($this->title)."\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";
                $feed.= "        ".$this->image->title."\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";
                }
                $feed.= "        ".htmlspecialchars(strip_tags(strtr($this->items[$i]->title,"\n\r","  ")))."\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";
            $feed.= "        ".FeedCreator::iTrunc(htmlspecialchars($this->title),100)."\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";
                $feed.= "            ".FeedCreator::iTrunc(htmlspecialchars($this->image->title),100)."\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";
                $feed.= "            ".FeedCreator::iTrunc(htmlspecialchars(strip_tags($this->items[$i]->title)),100)."\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:

    复制代码 代码如下:

    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.bkjia.com/';
        $item->description =$rowbrs['description'];
        $rss->addItem($item);
    }
    mysql_close($db);
    $rss->saveFeed("RSS2.0","rss.xml");

    希望本文所述对大家的php程序设计有所帮助。

    相关标签:
    来源:php.cn
    本站声明
    本文内容由网友自发贡献,版权归原作者所有,本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容,请联系admin@php.cn
    热门推荐
    热门教程
    更多>
    最新下载
    更多>
    网站特效
    网站源码
    网站素材
    前端模板