feedcreator.class.php

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			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 <[e-mail]>
 * @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 = "";

	var $cssStyleSheet = "";


	/**
	 * @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="") {
		$tzOffset = 0;
		if ($dateString=="") $dateString = date("r");

		//if (is_integer($dateString)) {
		if (is_numeric($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;
	}