Source for file feedcreator.php

<?php
/*************************************************************************
FeedCreator class v1.7.2
originally (c) Kai Blankenhorn
www.bitfolge.de
kaib@bitfolge.de
v1.3 work by Scott Reynen (scott@randomchaos.com) and Kai Blankenhorn
v1.5 OPML support by Dirk Clemens
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
***************************************************************************
Changelog:
v1.7.2    10-11-04
    license changed to LGPL
v1.7.1
    fixed a syntax bug
    fixed left over debug code
v1.7    07-18-04
    added HTML and JavaScript feeds (configurable via CSS) (thanks to Pascal Van Hecke)
    added HTML descriptions for all feed formats (thanks to Pascal Van Hecke)
    added a switch to select an external stylesheet (thanks to Pascal Van Hecke)
    changed default content-type to application/xml
    added character encoding setting
    fixed numerous smaller bugs (thanks to Sören Fuhrmann of golem.de)
    improved changing ATOM versions handling (thanks to August Trometer)
    improved the UniversalFeedCreator's useCached method (thanks to Sören Fuhrmann of golem.de)
    added charset output in HTTP headers (thanks to Sören Fuhrmann of golem.de)
    added Slashdot namespace to RSS 1.0 (thanks to Sören Fuhrmann of golem.de)
v1.6    05-10-04
    added stylesheet to RSS 1.0 feeds
    fixed generator comment (thanks Kevin L. Papendick and Tanguy Pruvot)
    fixed RFC822 date bug (thanks Tanguy Pruvot)
    added TimeZone customization for RFC8601 (thanks Tanguy Pruvot)
    fixed Content-type could be empty (thanks Tanguy Pruvot)
    fixed author/creator in RSS1.0 (thanks Tanguy Pruvot)
v1.6 beta    02-28-04
    added Atom 0.3 support (not all features, though)
    improved OPML 1.0 support (hopefully - added more elements)
    added support for arbitrary additional elements (use with caution)
    code beautification :-)
    considered beta due to some internal changes
v1.5.1    01-27-04
    fixed some RSS 1.0 glitches (thanks to Stéphane Vanpoperynghe)
    fixed some inconsistencies between documentation and code (thanks to Timothy Martin)
v1.5    01-06-04
    added support for OPML 1.0
    added more documentation
v1.4    11-11-03
    optional feed saving and caching
    improved documentation
    minor improvements
v1.3    10-02-03
    renamed to FeedCreator, as it not only creates RSS anymore
    added support for mbox
    tentative support for echo/necho/atom/pie/???
        
v1.2    07-20-03
    intelligent auto-truncating of RSS 0.91 attributes
    don't create some attributes when they're not set
    documentation improved
    fixed a real and a possible bug with date conversions
    code cleanup
v1.1    06-29-03
    added images to feeds
    now includes most RSS 0.91 attributes
    added RSS 2.0 feeds
v1.0    06-24-03
    initial release
***************************************************************************/
 
 
/*** GENERAL USAGE *********************************************************
include("feedcreator.class.php"); 
$rss = new UniversalFeedCreator(); 
$rss->useCached(); // use cached version if age<1 hour
$rss->title = "PHP news"; 
$rss->description = "daily news from the PHP scripting world"; 
//optional
$rss->descriptionTruncSize = 500;
$rss->descriptionHtmlSyndicated = true;
$rss->link = "http://www.dailyphp.net/news"; 
$rss->syndicationURL = "http://www.dailyphp.net/".$_SERVER["PHP_SELF"]; 
$image = new FeedImage(); 
$image->title = "dailyphp.net logo"; 
$image->url = "http://www.dailyphp.net/images/logo.gif"; 
$image->link = "http://www.dailyphp.net"; 
$image->description = "Feed provided by dailyphp.net. Click to visit."; 
//optional
$image->descriptionTruncSize = 500;
$image->descriptionHtmlSyndicated = true;
$rss->image = $image; 
// get your news items from somewhere, e.g. your database: 
mysql_select_db($dbHost, $dbUser, $dbPass); 
$res = mysql_query("SELECT * FROM news ORDER BY newsdate DESC"); 
while ($data = mysql_fetch_object($res)) { 
    $item = new FeedItem(); 
    $item->title = $data->title; 
    $item->link = $data->url; 
    $item->description = $data->short; 
    
    //optional
    item->descriptionTruncSize = 500;
    item->descriptionHtmlSyndicated = true;
    $item->date = $data->newsdate; 
    $item->source = "http://www.dailyphp.net"; 
    $item->author = "John Doe"; 
     
    $rss->addItem($item); 
} 
// valid format strings are: RSS0.91, RSS1.0, RSS2.0, PIE0.1 (deprecated),
// MBOX, OPML, ATOM, ATOM0.3, HTML, JS
echo $rss->saveFeed("RSS1.0", "news/feed.xml");
**************************************************************************
*          A little setup                                                 *
**************************************************************************/
 
 
// your local timezone, set to "" to disable or for GMT
define("TIME_ZONE","+01:00");
 
 
 
 
/**
 * Version string.
 **/
 
define("FEEDCREATOR_VERSION", "FeedCreator 1.7.2");
 
 
 
/**
 * A FeedItem is a part of a FeedCreator feed.
 *
 * @author Kai Blankenhorn <kaib@bitfolge.de>
 * @since 1.3
 */
class FeedItem extends HtmlDescribable {
    /**
     * Mandatory attributes of an item.
     */
    var $title, $description, $link;
    
    /**
     * Optional attributes of an item.
     */
    var $author, $authorEmail, $image, $category, $comments, $guid, $source, $creator;
    
    /**
     * Publishing date of an item. May be in one of the following formats:
     *
     *    RFC 822:
     *    "Mon, 20 Jan 03 18:05:41 +0400"
     *    "20 Jan 03 18:05:41 +0000"
     *
     *    ISO 8601:
     *    "2003-01-20T18:05:41+04:00"
     *
     *    Unix:
     *    1043082341
     */
    var $date;
    
    /**
     * Any additional elements to include as an assiciated array. All $key => $value pairs
     * will be included unencoded in the feed item in the form
     *     <$key>$value</$key>
     * Again: No encoding will be used! This means you can invalidate or enhance the feed
     * if $value contains markup. This may be abused to embed tags not implemented by
     * the FeedCreator class used.
     */
    var $additionalElements = Array();
 
    // on hold
    // var $source;
 
}
 
 
 
/**
 * An FeedImage may be added to a FeedCreator feed.
 * @author Kai Blankenhorn <kaib@bitfolge.de>
 * @since 1.3
 */
class FeedImage extends HtmlDescribable {
    /**
     * Mandatory attributes of an image.
     */
    var $title, $url, $link;
    
    /**
     * Optional attributes of an image.
     */
    var $width, $height, $description;
}
 
 
 
/**
 * An HtmlDescribable is an item within a feed that can have a description that may
 * include HTML markup.
 */
class HtmlDescribable {
    /**
     * Indicates whether the description field should be rendered in HTML.
     */
    var $descriptionHtmlSyndicated;
    
    /**
     * Indicates whether and to how many characters a description should be truncated.
     */
    var $descriptionTruncSize;
    
    /**
     * Returns a formatted description field, depending on descriptionHtmlSyndicated and
     * $descriptionTruncSize properties
     * @return    string    the formatted description
     */
    function getDescription() {
        $descriptionField = new FeedHtmlField($this->description);
        $descriptionField->syndicateHtml = $this->descriptionHtmlSyndicated;
        $descriptionField->truncSize = $this->descriptionTruncSize;
        return $descriptionField->output();
    }
 
}
 
 
/**
 * An FeedHtmlField describes and generates
 * a feed, item or image html field (probably a description). Output is
 * generated based on $truncSize, $syndicateHtml properties.
 * @author Pascal Van Hecke <feedcreator.class.php@vanhecke.info>
 * @version 1.6
 */
class FeedHtmlField {
    /**
     * Mandatory attributes of a FeedHtmlField.
     */
    var $rawFieldContent;
    
    /**
     * Optional attributes of a FeedHtmlField.
     * 
     */
    var $truncSize, $syndicateHtml;
    
    /**
     * Creates a new instance of FeedHtmlField.
     * @param  $string: if given, sets the rawFieldContent property
     */
    function FeedHtmlField($parFieldContent) {
        if ($parFieldContent) {
            $this->rawFieldContent = $parFieldContent;
        }
    }
        
        
    /**
     * Creates the right output, depending on $truncSize, $syndicateHtml properties.
     * @return string    the formatted field
     */
    function output() {
        // when field available and syndicated in html we assume 
        // - valid html in $rawFieldContent and we enclose in CDATA tags
        // - no truncation (truncating risks producing invalid html)
        if (!$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;
    }
 
}
 
 
 
/**
 * UniversalFeedCreator lets you choose during runtime which
 * format to build.
 * For general usage of a feed class, see the FeedCreator class
 * below or the example above.
 *
 * @since 1.3
 * @author Kai Blankenhorn <kaib@bitfolge.de>
 */
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 "1.0":
                // fall through
            case "RSS1.0":
                $this->_feed = new RSSCreator10();
                break;
            
            case "0.91":
                // fall through
            case "RSS0.91":
                $this->_feed = new RSSCreator091();
                break;
            
            case "PIE0.1":
                $this->_feed = new PIECreator01();
                break;
            
            case "MBOX":
                $this->_feed = new MBOXCreator();
                break;
            
            case "OPML":
                $this->_feed = new OPMLCreator();
                break;
                
            case "ATOM":
                // fall through: always the latest ATOM version
                
            case "ATOM0.3":
                $this->_feed = new AtomCreator03();
                break;
                
            case "HTML":
                $this->_feed = new HTMLCreator();
                break;
            
            case "JS":
                // fall through
            case "JAVASCRIPT":
                $this->_feed = new JSCreator();
                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};
            }
        }
    }
    
    /**
     * Creates a syndication feed based on the items previously added.
     *
     * @see        FeedCreator::addItem()
     * @param    string    format    format the feed should comply to. Valid values are:
     *             "PIE0.1", "mbox", "RSS0.91", "RSS1.0", "RSS2.0", "OPML", "ATOM0.3", "HTML", "JS"
     * @return    string    the contents of the feed.
     */
    function createFeed($format = "RSS0.91") {
        $this->_setFormat($format);
        return $this->_feed->createFeed();
    }
    
    
    
    /**
     * Saves this feed as a file on the local disk. After the file is saved, an HTTP redirect
     * header may be sent to redirect the use to the newly created file.
     * @since 1.4
     * 
     * @param    string    format    format the feed should comply to. Valid values are:
     *             "PIE0.1" (deprecated), "mbox", "RSS0.91", "RSS1.0", "RSS2.0", "OPML", "ATOM", "ATOM0.3", "HTML", "JS"
     * @param    string    filename    optional    the filename where a recent version of the feed is saved. If not specified, the filename is $_SERVER["PHP_SELF"] with the extension changed to .xml (see _generateFilename()).
     * @param    boolean    displayContents    optional    send the content of the file or not. If true, the file will be sent in the body of the response.
     */
    function saveFeed($format="RSS0.91", $filename="", $displayContents=true) {
        $this->_setFormat($format);
        $this->_feed->saveFeed($filename, $displayContents);
    }
 
 
   /**
    * Turns on caching and checks if there is a recent version of this feed in the cache.
    * If there is, an HTTP redirect header is sent.
    * To effectively use caching, you should create the FeedCreator object and call this method
    * before anything else, especially before you do the time consuming task to build the feed
    * (web fetching, for example).
    *
    * @param   string   format   format the feed should comply to. Valid values are:
    *        "PIE0.1" (deprecated), "mbox", "RSS0.91", "RSS1.0", "RSS2.0", "OPML", "ATOM0.3".
    * @param filename   string   optional the filename where a recent version of the feed is saved. If not specified, the filename is $_SERVER["PHP_SELF"] with the extension changed to .xml (see _generateFilename()).
    * @param timeout int      optional the timeout in seconds before a cached version is refreshed (defaults to 3600 = 1 hour)
    */
   function useCached($format="RSS0.91", $filename="", $timeout=3600) {
      $this->_setFormat($format);
      $this->_feed->useCached($filename, $timeout);
   }
 
}
 
 
/**
 * FeedCreator is the abstract base implementation for concrete
 * implementations that implement a specific format of syndication.
 *
 * @abstract
 * @author Kai Blankenhorn <kaib@bitfolge.de>
 * @since 1.4
 */
class FeedCreator extends HtmlDescribable {
 
    /**
     * Mandatory attributes of a feed.
     */
    var $title, $description, $link;
    
    
    /**
     * Optional attributes of a feed.
     */
    var $syndicationURL, $image, $language, $copyright, $pubDate, $lastBuildDate, $editor, $editorEmail, $webmaster, $category, $docs, $ttl, $rating, $skipHours, $skipDays;
 
    /**
    * The url of the external xsl stylesheet used to format the naked rss feed.
    * Ignored in the output when empty.
    */
    var $xslStyleSheet = "";
    
    
    /**
     * @access private
     */
    var $items = Array();
     
    
    /**
     * This feed's MIME content type.
     * @since 1.4
     * @access private
     */
    var $contentType = "application/xml";
    
    
    /**
     * This feed's character encoding.
     * @since 1.6.1
     ***/
    var $encoding = "ISO-8859-1";
    
    
    /**
     * Any additional elements to include as an assiciated array. All $key => $value pairs
     * will be included unencoded in the feed in the form
     *     <$key>$value</$key>
     * Again: No encoding will be used! This means you can invalidate or enhance the feed
     * if $value contains markup. This may be abused to embed tags not implemented by
     * the FeedCreator class used.
     */
    var $additionalElements = Array();
   
    
    /**
     * Adds an FeedItem to the feed.
     *
     * @param object FeedItem $item The FeedItem to add to the feed.
     * @access public
     */
    function addItem($item) {
        $this->items[] = $item;
    }
    
    
    /**
     * Truncates a string to a certain length at the most sensible point.
     * First, if there's a '.' character near the end of the string, the string is truncated after this character.
     * If there is no '.', the string is truncated after the last ' ' character.
     * If the string is truncated, " ..." is appended.
     * If the string is already shorter than $length, it is returned unchanged.
     * 
     * @static
     * @param string    string A string to be truncated.
     * @param int        length the maximum length the string should be truncated to
     * @return string    the truncated string
     */
    function iTrunc($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)." ...";
            
    }
    
    
    /**
     * Creates a comment indicating the generator of this feed.
     * The format of this comment seems to be recognized by
     * Syndic8.com.
     */
    function _createGeneratorComment() {
        return "<!-- generator=\"".FEEDCREATOR_VERSION."\" -->\n";
    }
    
    
    /**
     * Creates a string containing all additional elements specified in
     * $additionalElements.
     * @param    elements    array    an associative array containing key => value pairs
     * @param indentString    string    a string that will be inserted before every generated line
     * @return    string    the XML tags corresponding to $additionalElements
     */
    function _createAdditionalElements($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;
    }
    
    
    /**
     * Builds the feed's text.
     * @abstract
     * @return    string    the feed's complete text
     */
    function createFeed() {
    }
    
    /**
     * Generate a filename for the feed cache file. The result will be $_SERVER["PHP_SELF"] with the extension changed to .xml.
     * For example:
     * 
     * echo $_SERVER["PHP_SELF"]."\n";
     * echo FeedCreator::_generateFilename();
     * 
     * would produce:
     * 
     * /rss/latestnews.php
     * latestnews.xml
     *
     * @return string the feed cache filename
     * @since 1.4
     * @access private
     */
    function _generateFilename() {
        $fileInfo = pathinfo($_SERVER["PHP_SELF"]);
        return substr($fileInfo["basename"],0,-(strlen($fileInfo["extension"])+1)).".xml";
    }
    
    
    /**
     * @since 1.4
     * @access private
     */
    function _redirect($filename) {
        // attention, heavily-commented-out-area
        
        // maybe use this in addition to file time checking
        //Header("Expires: ".date("r",time()+$this->_timeout));
        
        /* no caching at all, doesn't seem to work as good:
        Header("Cache-Control: no-cache");
        Header("Pragma: no-cache");
        */
        
        // HTTP redirect, some feed readers' simple HTTP implementations don't follow it
        //Header("Location: ".$filename);
 
        Header("Content-Type: ".$this->contentType."; charset=".$this->encoding."; filename=".basename($filename));
        Header("Content-Disposition: inline; filename=".basename($filename));
        readfile($filename, "r");
        die();
    }
    
    /**
     * Turns on caching and checks if there is a recent version of this feed in the cache.
     * If there is, an HTTP redirect header is sent.
     * To effectively use caching, you should create the FeedCreator object and call this method
     * before anything else, especially before you do the time consuming task to build the feed
     * (web fetching, for example).
     * @since 1.4
     * @param filename    string    optional    the filename where a recent version of the feed is saved. If not specified, the filename is $_SERVER["PHP_SELF"] with the extension changed to .xml (see _generateFilename()).
     * @param timeout    int        optional    the timeout in seconds before a cached version is refreshed (defaults to 3600 = 1 hour)
     */
    function useCached($filename="", $timeout=3600) {
        $this->_timeout = $timeout;
        if ($filename=="") {
            $filename = $this->_generateFilename();
        }
        if (file_exists($filename) AND (time()-filemtime($filename) < $timeout)) {
            $this->_redirect($filename);
        }
    }
    
    
    /**
     * Saves this feed as a file on the local disk. After the file is saved, a redirect
     * header may be sent to redirect the user to the newly created file.
     * @since 1.4
     * 
     * @param filename    string    optional    the filename where a recent version of the feed is saved. If not specified, the filename is $_SERVER["PHP_SELF"] with the extension changed to .xml (see _generateFilename()).
     * @param redirect    boolean    optional    send an HTTP redirect header or not. If true, the user will be automatically redirected to the created file.
     */
    function saveFeed($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 />";
        }
    }
    
}
 
 
/**
 * FeedDate is an internal class that stores a date for a feed or feed item.
 * Usually, you won't need to use this.
 */
class FeedDate {
    var $unix;
    
    /**
     * Creates a new instance of FeedDate representing a given date.
     * Accepts RFC 822, ISO 8601 date formats as well as unix time stamps.
     * @param mixed $dateString optional the date this FeedDate will represent. If not specified, the current date and time is used.
     */
    function FeedDate($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") AND $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;
    }
 
    /**
     * Gets the date stored in this FeedDate as an RFC 822 date.
     *
     * @return a date in RFC 822 format
     */
    function rfc822() {
        //return gmdate("r",$this->unix);
        $date = gmdate("D, d M Y H:i:s", $this->unix);
        if (TIME_ZONE!="") $date .= " ".str_replace(":","",TIME_ZONE);
        return $date;
    }
    
    /**
     * Gets the date stored in this FeedDate as an ISO 8601 date.
     *
     * @return a date in ISO 8601 format
     */
    function iso8601() {
        $date = gmdate("Y-m-d\TH:i:sO",$this->unix);
        $date = substr($date,0,22) . ':' . substr($date,-2);
        if (TIME_ZONE!="") $date = str_replace("+00:00",TIME_ZONE,$date);
        return $date;
    }
    
    /**
     * Gets the date stored in this FeedDate as unix time stamp.
     *
     * @return a date as a unix time stamp
     */
    function unix() {
        return $this->unix;
    }
}
 
 
/**
 * RSSCreator10 is a FeedCreator that implements RDF Site Summary (RSS) 1.0.
 *
 * @see http://www.purl.org/rss/1.0/
 * @since 1.3
 * @author Kai Blankenhorn <kaib@bitfolge.de>
 */
class RSSCreator10 extends FeedCreator {
 
    /**
     * Builds the RSS feed's text. The feed will be compliant to RDF Site Summary (RSS) 1.0.
     * The feed will contain all items previously added in the same order.
     * @return    string    the feed's complete text
     */
    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.=