--- a/lib/FeedWriter/FeedWriter.php +++ b/lib/FeedWriter/FeedWriter.php @@ -1,1 +1,514 @@ - +<?php + +/* + * Copyright (C) 2008 Anis uddin Ahmad <anisniit@gmail.com> + * Copyright (C) 2010-2012 Michael Bemmerl <mail@mx-server.de> + * + * This file is part of the "Universal Feed Writer" project. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +// RSS 0.90 Officially obsoleted by 1.0 +// RSS 0.91, 0.92, 0.93 and 0.94 Officially obsoleted by 2.0 +// So, define constants for RSS 1.0, RSS 2.0 and ATOM + +define('RSS1', 'RSS 1.0', true); +define('RSS2', 'RSS 2.0', true); +define('ATOM', 'ATOM', true); + +if (!class_exists('FeedItem')) + require dirname(__FILE__) . '/FeedItem.php'; + +/** + * Universal Feed Writer class + * + * Generate RSS 1.0, RSS2.0 and ATOM Feeds + * + * @package UniversalFeedWriter + * @author Anis uddin Ahmad <anisniit@gmail.com> + * @link http://www.ajaxray.com/projects/rss + */ +abstract class FeedWriter +{ + private $channels = array(); // Collection of channel elements + private $items = array(); // Collection of items as object of FeedItem class. + private $data = array(); // Store some other version wise data + private $CDATAEncoding = array(); // The tag names which have to encoded as CDATA + + private $version = null; + + /** + * Constructor + * + * @param constant the version constant (RSS1/RSS2/ATOM). + */ + protected function __construct($version = RSS2) + { + $this->version = $version; + + // Setting default value for essential channel elements + $this->channels['title'] = $version . ' Feed'; + $this->channels['link'] = 'http://www.ajaxray.com/blog'; + + //Tag names to encode in CDATA + $this->CDATAEncoding = array('description', 'content:encoded', 'summary'); + } + + // Start # public functions --------------------------------------------- + + /** + * Set a channel element + * @access public + * @param string name of the channel tag + * @param string content of the channel tag + * @return void + */ + public function setChannelElement($elementName, $content) + { + $this->channels[$elementName] = $content; + } + + /** + * Set multiple channel elements from an array. Array elements + * should be 'channelName' => 'channelContent' format. + * + * @access public + * @param array array of channels + * @return void + */ + public function setChannelElementsFromArray($elementArray) + { + if (!is_array($elementArray)) + return; + + foreach ($elementArray as $elementName => $content) + { + $this->setChannelElement($elementName, $content); + } + } + + /** + * Genarate the actual RSS/ATOM file + * + * @access public + * @param bool FALSE if the specific feed media type should be send. + * @return void + */ + public function generateFeed($useGenericContentType = FALSE) + { + $contentType = "text/xml"; + + if (!$useGenericContentType) + { + switch($this->version) + { + case RSS2 : $contentType = "application/rss+xml"; + break; + case RSS1 : $contentType = "application/rdf+xml"; + break; + case ATOM : $contentType = "application/atom+xml"; + break; + } + } + + header("Content-Type: " . $contentType); + + $this->printHeader(); + $this->printChannels(); + $this->printItems(); + $this->printFooter(); + } + + /** + * Create a new FeedItem. + * + * @access public + * @return object instance of FeedItem class + */ + public function createNewItem() + { + $Item = new FeedItem($this->version); + return $Item; + } + + /** + * Add a FeedItem to the main class + * + * @access public + * @param object instance of FeedItem class + * @return void + */ + public function addItem(FeedItem $feedItem) + { + if ($feedItem->getVersion() != $this->version) + die('Feed type mismatch: This instance can handle ' . $this->version . ' feeds only, but item with type ' . $feedItem->getVersion() . ' given.'); + + $this->items[] = $feedItem; + } + + + // Wrapper functions ------------------------------------------------------------------- + + /** + * Set the 'title' channel element + * + * @access public + * @param string value of 'title' channel tag + * @return void + */ + public function setTitle($title) + { + $this->setChannelElement('title', $title); + } + + /** + * Set the 'updated' channel element of an ATOM feed + * + * @access public + * @param string value of 'updated' channel tag + * @return void + */ + public function setDate($date) + { + if ($this->version != ATOM) + return; + + if ($date instanceof DateTime) + $date = $date->format(DateTime::ATOM); + else if(is_numeric($date)) + $date = date(DATE_ATOM, $date); + else + $date = date(DATE_ATOM, strtotime($date)); + + $this->setChannelElement('updated', $date); + } + + /** + * Set the 'description' channel element + * + * @access public + * @param string value of 'description' channel tag + * @return void + */ + public function setDescription($desciption) + { + if ($this->version != ATOM) + $this->setChannelElement('description', $desciption); + } + + /** + * Set the 'link' channel element + * + * @access public + * @param string value of 'link' channel tag + * @return void + */ + public function setLink($link) + { + $this->setChannelElement('link', $link); + } + + /** + * Set the 'image' channel element + * + * @access public + * @param string title of image + * @param string link url of the image + * @param string path url of the image + * @return void + */ + public function setImage($title, $link, $url) + { + $this->setChannelElement('image', array('title'=>$title, 'link'=>$link, 'url'=>$url)); + } + + /** + * Set the 'about' channel element. Only for RSS 1.0 + * + * @access public + * @param string value of 'about' channel tag + * @return void + */ + public function setChannelAbout($url) + { + $this->data['ChannelAbout'] = $url; + } + + /** + * Generates an UUID + * @author Anis uddin Ahmad <admin@ajaxray.com> + * @param string an optional prefix + * @return string the formated uuid + */ + public static function uuid($key = null, $prefix = '') + { + $key = ($key == null)? uniqid(rand()) : $key; + $chars = md5($key); + $uuid = substr($chars,0,8) . '-'; + $uuid .= substr($chars,8,4) . '-'; + $uuid .= substr($chars,12,4) . '-'; + $uuid .= substr($chars,16,4) . '-'; + $uuid .= substr($chars,20,12); + + return $prefix . $uuid; + } + // End # public functions ---------------------------------------------- + + // Start # private functions ---------------------------------------------- + + /** + * Prints the xml and rss namespace + * + * @access private + * @return void + */ + private function printHeader() + { + $out = '<?xml version="1.0" encoding="utf-8"?>' . PHP_EOL; + + if($this->version == RSS2) + { + $out .= '<rss version="2.0" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:wfw="http://wellformedweb.org/CommentAPI/">'; + } + elseif($this->version == RSS1) + { + $out .= '<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns="http://purl.org/rss/1.0/" xmlns:dc="http://purl.org/dc/elements/1.1/">'; + } + else if($this->version == ATOM) + { + $out .= '<feed xmlns="http://www.w3.org/2005/Atom">'; + } + + $out .= PHP_EOL; + + echo $out; + } + + /** + * Closes the open tags at the end of file + * + * @access private + * @return void + */ + private function printFooter() + { + if($this->version == RSS2) + { + echo '</channel>' . PHP_EOL . '</rss>'; + } + elseif($this->version == RSS1) + { + echo '</rdf:RDF>'; + } + else if($this->version == ATOM) + { + echo '</feed>'; + } + } + + /** + * Creates a single node as xml format + * + * @access private + * @param string name of the tag + * @param mixed tag value as string or array of nested tags in 'tagName' => 'tagValue' format + * @param array Attributes(if any) in 'attrName' => 'attrValue' format + * @return string formatted xml tag + */ + private function makeNode($tagName, $tagContent, $attributes = null) + { + $nodeText = ''; + $attrText = ''; + + if(is_array($attributes) && count($attributes) > 0) + { + foreach ($attributes as $key => $value) + { + $value = htmlspecialchars($value); + $attrText .= " $key=\"$value\" "; + } + + // Get rid of the last whitespace + $attrText = substr($attrText, 0, strlen($attrText) - 1); + } + + if(is_array($tagContent) && $this->version == RSS1) + { + $attrText = ' rdf:parseType="Resource"'; + } + + $attrText .= (in_array($tagName, $this->CDATAEncoding) && $this->version == ATOM) ? ' type="html"' : ''; + $nodeText .= "<{$tagName}{$attrText}>"; + $nodeText .= (in_array($tagName, $this->CDATAEncoding)) ? '<![CDATA[' : ''; + + if(is_array($tagContent)) + { + foreach ($tagContent as $key => $value) + { + $nodeText .= $this->makeNode($key, $value); + } + } + else + { + $nodeText .= (in_array($tagName, $this->CDATAEncoding))? $this->sanitizeCDATA($tagContent) : htmlspecialchars($tagContent); + } + + $nodeText .= (in_array($tagName, $this->CDATAEncoding)) ? ']]>' : ''; + $nodeText .= "</$tagName>" . PHP_EOL; + + return $nodeText; + } + + /** + * @desc Print channels + * @access private + * @return void + */ + private function printChannels() + { + //Start channel tag + switch ($this->version) + { + case RSS2: + echo '<channel>' . PHP_EOL; + break; + case RSS1: + echo (isset($this->data['ChannelAbout']))? "<channel rdf:about=\"{$this->data['ChannelAbout']}\">" : "<channel rdf:about=\"{$this->channels['link']}\">"; + break; + } + + //Print Items of channel + foreach ($this->channels as $key => $value) + { + if($this->version == ATOM && $key == 'link') + { + // ATOM prints link element as href attribute + echo $this->makeNode($key,'', array('href' => $value)); + //Add the id for ATOM + echo $this->makeNode('id', FeedWriter::uuid($value, 'urn:uuid:')); + } + else + { + echo $this->makeNode($key, $value); + } + + } + + //RSS 1.0 have special tag <rdf:Seq> with channel + if($this->version == RSS1) + { + echo "<items>" . PHP_EOL . "<rdf:Seq>" . PHP_EOL; + foreach ($this->items as $item) + { + $thisItems = $item->getElements(); + echo "<rdf:li resource=\"{$thisItems['link']['content']}\"/>" . PHP_EOL; + } + echo "</rdf:Seq>" . PHP_EOL . "</items>" . PHP_EOL . "</channel>" . PHP_EOL; + } + } + + /** + * Prints formatted feed items + * + * @access private + * @return void + */ + private function printItems() + { + foreach ($this->items as $item) + { + $thisItems = $item->getElements(); + + //the argument is printed as rdf:about attribute of item in rss 1.0 + echo $this->startItem($thisItems['link']['content']); + + foreach ($thisItems as $feedItem) + { + echo $this->makeNode($feedItem['name'], $feedItem['content'], $feedItem['attributes']); + } + echo $this->endItem(); + } + } + + /** + * Make the starting tag of channels + * + * @access private + * @param string The vale of about tag which is used for RSS 1.0 only. + * @return void + */ + private function startItem($about = false) + { + if($this->version == RSS2) + { + echo '<item>' . PHP_EOL; + } + else if($this->version == RSS1) + { + if($about) + { + echo "<item rdf:about=\"$about\">" . PHP_EOL; + } + else + { + die("link element is not set." . PHP_EOL . "It's required for RSS 1.0 to be used as the about attribute of the item tag."); + } + } + else if($this->version == ATOM) + { + echo "<entry>" . PHP_EOL; + } + } + + /** + * Closes feed item tag + * + * @access private + * @return void + */ + private function endItem() + { + if($this->version == RSS2 || $this->version == RSS1) + { + echo '</item>' . PHP_EOL; + } + else if($this->version == ATOM) + { + echo "</entry>" . PHP_EOL; + } + } + + /** + * Sanitizes data which will be later on returned as CDATA in the feed. + * + * A "]]>" respectively "<![CDATA" in the data would break the CDATA in the + * XML, so the brackets are converted to a HTML entity. + * + * @access private + * @param string Data to be sanitized + * @return string Sanitized data + */ + private function sanitizeCDATA($text) + { + $text = str_replace("]]>", "]]>", $text); + $text = str_replace("<![CDATA[", "<![CDATA[", $text); + + return $text; + } + + // End # private functions ---------------------------------------------- + +} // end of class FeedWriter +