Heim > php教程 > php手册 > php生成RSS订阅的方法

php生成RSS订阅的方法

WBOY
Freigeben: 2016-06-13 09:14:40
Original
994 Leute haben es durchsucht

php生成RSS订阅的方法

 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:

代码如下:




脚本之家
http://www.jb51.net/
脚本之家

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:

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:

    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.jb51.net/';
    $item->description =$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。

    Verwandte Etiketten:
    Quelle:php.cn
    Erklärung dieser Website
    Der Inhalt dieses Artikels wird freiwillig von Internetnutzern beigesteuert und das Urheberrecht liegt beim ursprünglichen Autor. Diese Website übernimmt keine entsprechende rechtliche Verantwortung. Wenn Sie Inhalte finden, bei denen der Verdacht eines Plagiats oder einer Rechtsverletzung besteht, wenden Sie sich bitte an admin@php.cn
    Beliebte Empfehlungen
    Beliebte Tutorials
    Mehr>
    Neueste Downloads
    Mehr>
    Web-Effekte
    Quellcode der Website
    Website-Materialien
    Frontend-Vorlage