php生成RSS訂閱的方法_PHP教程

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這篇文章主要介紹了PHP 5.3和PHP 5.4出現(xiàn)FastCGI Error解決方法,需要的朋友可以參考下不少童鞋在配置完P(guān)HP 5.3或者PHP 5.4網(wǎng)站源碼后打開出錯，提示代碼如下: FastCGI Error The FastCGI Handler was unable to process the request. Error Details: Error Number: 1

本文實(shí)例講述了php生成RSS訂閱的方法。分享給大家供大家參考。具體分析如下：

RSS（簡易信息聚合，也叫聚合內(nèi)容）是一種描述和同步網(wǎng)站內(nèi)容的格式。RSS可以是以下三個(gè)解釋的其中一個(gè)： Really Simple Syndication；RDF (Resource Description Framework) Site Summary； Rich Site Summary。但其實(shí)這三個(gè)解釋都是指同一種Syndication的技術(shù)。RSS目前廣泛用于網(wǎng)上新聞頻道，blog和wiki。使用RSS訂閱能更快地獲取信息，網(wǎng)站提供RSS輸出，有利于讓用戶獲取網(wǎng)站內(nèi)容的最新更新。網(wǎng)絡(luò)用戶可以在客戶端借助于支持RSS的聚合工具軟件，在不打開網(wǎng)站內(nèi)容頁面的情況下閱讀支持RSS輸出的網(wǎng)站內(nèi)容。
從技術(shù)上來說一個(gè)RSS文件就是一段規(guī)范的XML數(shù)據(jù)，該文件一般以rss，xml或者rdf作為后綴，下面是一段 rss 文件的內(nèi)容示例：

代碼如下: <?xml version="1.0" encoding="utf-8"?>
<rss version="2.0">
<channel>
<title>腳本之家</title>
<link>http://www.jb51.net/</link>
<description>腳本之家</description>
<item>
<title>RSS Tutorial</title>
<link>網(wǎng)站地址/rss</link>
<description>New RSS tutorial on W3School</description>
</item>
<item>
<title>XML Tutorial</title>
<link>網(wǎng)站地址/xml</link>
<description>New XML tutorial on W3School</description>
</item>
</channel>
</rss>

下面分享一段使用 php 動態(tài)生成 RSS 的代碼示例：

代碼如下: <?php
/**
** php 動態(tài)生成 RSS 類
**/
define("TIME_ZONE","");
define("FEEDCREATOR_VERSION","www.jb51.net");//您的網(wǎng)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){
$result="<![CDATA[".$this->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>$value</$key>\n";
}
}
return $ae;
}

function _createStylesheetReferences(){
$xml="";
if($this->cssStyleSheet) $xml .= "<?xml-stylesheet href=\"".$this->cssStyleSheet."\" type=\"text/css\"?>\n";
if($this->xslStyleSheet) $xml .= "<?xml-stylesheet href=\"".$this->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 "<br /><b>Error creating feed file, please check write permissions.</b><br />";
}
}
}

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(){
$feed="<?xml version=\"1.0\" encoding=\"".$this->encoding."\"?>\n";
$feed.= $this->_createGeneratorComment();
if($this->cssStyleSheet==""){
$cssStyleSheet="http://www.w3.org/2000/08/w3c-synd/style.css";
}
$feed.= $this->_createStylesheetReferences();
$feed.= "<rdf:RDF\n";
$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";
$feed.= " <channel rdf:about=\"".$this->syndicationURL."\">\n";
$feed.= " <title>".htmlspecialchars($this->title)."</title>\n";
$feed.= " <description>".htmlspecialchars($this->description)."</description>\n";
$feed.= " <link>".$this->link."</link>\n";
if($this->image!=null){
$feed.= " <image rdf:resource=\"".$this->image->url."\" />\n";
}
$now=new FeedDate();
$feed.= " <dc:date>".htmlspecialchars($now->iso8601())."</dc:date>\n";
$feed.= " <items>\n";
$feed.= " <rdf:Seq>\n";
for ($i=0;$i<count($this->items);$i++){
$feed.= " <rdf:li rdf:resource=\"".htmlspecialchars($this->items[$i]->link)."\"/>\n";
}
$feed.= " </rdf:Seq>\n";
$feed.= " </items>\n";
$feed.= " </channel>\n";
if($this->image!=null){
$feed.= " <image rdf:about=\"".$this->image->url."\">\n";
$feed.= " <title>".$this->image->title."</title>\n";
$feed.= " <link>".$this->image->link."</link>\n";
$feed.= " <url>".$this->image->url."</url>\n";
$feed.= " </image>\n";
}
$feed.= $this->_createAdditionalElements($this->additionalElements," ");

for ($i=0;$i<count($this->items);$i++){
$feed.= " <item rdf:about=\"".htmlspecialchars($this->items[$i]->link)."\">\n";
//$feed.= " <dc:type>Posting</dc:type>\n";
$feed.= " <dc:format>text/html</dc:format>\n";
if($this->items[$i]->date!=null){
$itemDate=new FeedDate($this->items[$i]->date);
$feed.= " <dc:date>".htmlspecialchars($itemDate->iso8601())."</dc:date>\n";
}
if($this->items[$i]->source!=""){
$feed.= " <dc:source>".htmlspecialchars($this->items[$i]->source)."</dc:source>\n";
}
if($this->items[$i]->author!=""){
$feed.= " <dc:creator>".htmlspecialchars($this->items[$i]->author)."</dc:creator>\n";
}
$feed.= " <title>".htmlspecialchars(strip_tags(strtr($this->items[$i]->title,"\n\r"," ")))."</title>\n";
$feed.= " <link>".htmlspecialchars($this->items[$i]->link)."</link>\n";
$feed.= " <description>".htmlspecialchars($this->items[$i]->description)."</description>\n";
$feed.= $this->_createAdditionalElements($this->items[$i]->additionalElements," ");
$feed.= " </item>\n";
}
$feed.= "</rdf:RDF>\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(){
$feed="<?xml version=\"1.0\" encoding=\"".$this->encoding."\"?>\n";
$feed.= $this->_createGeneratorComment();
$feed.= $this->_createStylesheetReferences();
$feed.= "<rss version=\"".$this->RSSVersion."\">\n";
$feed.= " <channel>\n";
$feed.= " <title>".FeedCreator::iTrunc(htmlspecialchars($this->title),100)."</title>\n";
$this->descriptionTruncSize=500;
$feed.= " <description>".$this->getDescription()."</description>\n";
$feed.= " <link>".$this->link."</link>\n";
$now=new FeedDate();
$feed.= " <lastBuildDate>".htmlspecialchars($now->rfc822())."</lastBuildDate>\n";
$feed.= " <generator>".FEEDCREATOR_VERSION."</generator>\n";

if($this->image!=null){
$feed.= " <image>\n";
$feed.= " <url>".$this->image->url."</url>\n";
$feed.= " <title>".FeedCreator::iTrunc(htmlspecialchars($this->image->title),100)."</title>\n";
$feed.= " <link>".$this->image->link."</link>\n";
if($this->image->width!=""){
$feed.= " <width>".$this->image->width."</width>\n";
}
if($this->image->height!=""){
$feed.= " <height>".$this->image->height."</height>\n";
}
if($this->image->description!=""){
$feed.= " <description>".$this->image->getDescription()."</description>\n";
}
$feed.= " </image>\n";
}
if($this->language!=""){
$feed.= " <language>".$this->language."</language>\n";
}
if($this->copyright!=""){
$feed.= " <copyright>".FeedCreator::iTrunc(htmlspecialchars($this->copyright),100)."</copyright>\n";
}
if($this->editor!=""){
$feed.= " <managingEditor>".FeedCreator::iTrunc(htmlspecialchars($this->editor),100)."</managingEditor>\n";
}
if($this->webmaster!=""){
$feed.= " <webMaster>".FeedCreator::iTrunc(htmlspecialchars($this->webmaster),100)."</webMaster>\n";
}
if($this->pubDate!=""){
$pubDate=new FeedDate($this->pubDate);
$feed.= " <pubDate>".htmlspecialchars($pubDate->rfc822())."</pubDate>\n";
}
if($this->category!=""){
$feed.= " <category>".htmlspecialchars($this->category)."</category>\n";
}
if($this->docs!=""){
$feed.= " <docs>".FeedCreator::iTrunc(htmlspecialchars($this->docs),500)."</docs>\n";
}
if($this->ttl!=""){
$feed.= " <ttl>".htmlspecialchars($this->ttl)."</ttl>\n";
}
if($this->rating!=""){
$feed.= " <rating>".FeedCreator::iTrunc(htmlspecialchars($this->rating),500)."</rating>\n";
}
if($this->skipHours!=""){
$feed.= " <skipHours>".htmlspecialchars($this->skipHours)."</skipHours>\n";
}
if($this->skipDays!=""){
$feed.= " <skipDays>".htmlspecialchars($this->skipDays)."</skipDays>\n";
}
$feed.= $this->_createAdditionalElements($this->additionalElements," ");

for ($i=0;$i<count($this->items);$i++){
$feed.= " <item>\n";
$feed.= " <title>".FeedCreator::iTrunc(htmlspecialchars(strip_tags($this->items[$i]->title)),100)."</title>\n";
$feed.= " <link>".htmlspecialchars($this->items[$i]->link)."</link>\n";
$feed.= " <description>".$this->items[$i]->getDescription()."</description>\n";

if($this->items[$i]->author!=""){
$feed.= " <author>".htmlspecialchars($this->items[$i]->author)."</author>\n";
}
/*
// on hold
if($this->items[$i]->source!=""){
$feed.= " <source>".htmlspecialchars($this->items[$i]->source)."</source>\n";
}
*/
if($this->items[$i]->category!=""){
$feed.= " <category>".htmlspecialchars($this->items[$i]->category)."</category>\n";
}
if($this->items[$i]->comments!=""){
$feed.= " <comments>".htmlspecialchars($this->items[$i]->comments)."</comments>\n";
}
if($this->items[$i]->date!=""){
$itemDate=new FeedDate($this->items[$i]->date);
$feed.= " <pubDate>".htmlspecialchars($itemDate->rfc822())."</pubDate>\n";
}
if($this->items[$i]->guid!=""){
$feed.= " <guid>".htmlspecialchars($this->items[$i]->guid)."</guid>\n";
}
$feed.= $this->_createAdditionalElements($this->items[$i]->additionalElements," ");
$feed.= " </item>\n";
}
$feed.= " </channel>\n";
$feed.= "</rss>\n";
return $feed;
}
}

class RSSCreator20 extends RSSCreator091{

function RSSCreator20(){
parent::_setRSSVersion("2.0");
}
}

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