full-text-rss/libraries/feedwriter/FeedWriter.php
2011-03-23 23:39:01 +01:00

481 lines
11 KiB
PHP

<?php
// 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);
/**
* Univarsel Feed Writer class
*
* Genarate RSS 1.0, RSS2.0 and ATOM Feed.
* Modified for FiveFilters.org's Full-Text RSS project
* to allow for inclusion of hubs
*
* @package UnivarselFeedWriter
* @author Anis uddin Ahmad <anisniit@gmail.com>
* @link http://www.ajaxray.com/projects/rss
*/
class FeedWriter
{
private $self = null; // self URL - http://feed2.w3.org/docs/warning/MissingAtomSelfLink.html
private $hubs = array(); // PubSubHubbub hubs
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 $xsl = null; // stylesheet to render RSS (used by Chrome)
private $version = null;
/**
* Constructor
*
* @param constant the version constant (RSS1/RSS2/ATOM).
*/
function __construct($version = RSS2)
{
$this->version = $version;
// Setting default value for assential channel elements
$this->channels['title'] = $version . ' Feed';
$this->channels['link'] = 'http://www.ajaxray.com/blog';
//Tag names to encode in CDATA
$this->CDATAEncoding = array('description', 'content:encoded', 'content', 'subtitle', 'summary');
}
// Start # public functions ---------------------------------------------
/**
* Set a channel element
* @access public
* @param srting name of the channel tag
* @param string content of the channel tag
* @return void
*/
public function setChannelElement($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
* @return void
*/
public function genarateFeed()
{
header("Content-type: text/xml; charset=UTF-8");
$this->printHead();
$this->printChannels();
$this->printItems();
$this->printTale();
}
/**
* 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)
{
$this->items[] = $feedItem;
}
// Wrapper functions -------------------------------------------------------------------
/**
* Set the 'title' channel element
*
* @access public
* @param srting value of 'title' channel tag
* @return void
*/
public function setTitle($title)
{
$this->setChannelElement('title', $title);
}
/**
* Add a hub to the channel element
*
* @access public
* @param string URL
* @return void
*/
public function addHub($hub)
{
$this->hubs[] = $hub;
}
/**
* Set XSL URL
*
* @access public
* @param string URL
* @return void
*/
public function setXsl($xsl)
{
$this->xsl = $xsl;
}
/**
* Set self URL
*
* @access public
* @param string URL
* @return void
*/
public function setSelf($self)
{
$this->self = $self;
}
/**
* Set the 'description' channel element
*
* @access public
* @param srting value of 'description' channel tag
* @return void
*/
public function setDescription($desciption)
{
$tag = ($this->version == ATOM)? 'subtitle' : 'description';
$this->setChannelElement($tag, $desciption);
}
/**
* Set the 'link' channel element
*
* @access public
* @param srting value of 'link' channel tag
* @return void
*/
public function setLink($link)
{
$this->setChannelElement('link', $link);
}
/**
* Set the 'image' channel element
*
* @access public
* @param srting title of image
* @param srting link url of the imahe
* @param srting path url of the image
* @return void
*/
public function setImage($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 srting value of 'about' channel tag
* @return void
*/
public function setChannelAbout($url)
{
$this->data['ChannelAbout'] = $url;
}
/**
* Genarates an UUID
* @author Anis uddin Ahmad <admin@ajaxray.com>
* @param string an optional prefix
* @return string the formated uuid
*/
public function uuid($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 printHead()
{
$out = '<?xml version="1.0" encoding="utf-8"?>' . "\n";
if($this->version == RSS2)
{
if ($this->xsl) $out .= '<?xml-stylesheet type="text/xsl" href="'.htmlspecialchars($this->xsl).'"?>' . PHP_EOL;
$out .= '<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">' . PHP_EOL;
}
elseif($this->version == RSS1)
{
$out .= '<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns="http://purl.org/rss/1.0/"
xmlns:dc="http://purl.org/dc/elements/1.1/"
>' . PHP_EOL;;
}
else if($this->version == ATOM)
{
$out .= '<feed xmlns="http://www.w3.org/2005/Atom">' . PHP_EOL;;
}
echo $out;
}
/**
* Closes the open tags at the end of file
*
* @access private
* @return void
*/
private function printTale()
{
if($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 srting 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))
{
foreach ($attributes as $key => $value)
{
$attrText .= " $key=\"$value\" ";
}
}
if(is_array($tagContent) && $this->version == RSS1)
{
$attrText = ' rdf:parseType="Resource"';
}
$attrText .= (in_array($tagName, $this->CDATAEncoding) && $this->version == ATOM)? ' type="html" ' : '';
//$nodeText .= (in_array($tagName, $this->CDATAEncoding))? "<{$tagName}{$attrText}><![CDATA[" : "<{$tagName}{$attrText}>";
$nodeText .= "<{$tagName}{$attrText}>";
if(is_array($tagContent))
{
foreach ($tagContent as $key => $value)
{
$nodeText .= $this->makeNode($key, $value);
}
}
else
{
//$nodeText .= (in_array($tagName, $this->CDATAEncoding))? $tagContent : htmlentities($tagContent);
$nodeText .= htmlspecialchars($tagContent);
}
//$nodeText .= (in_array($tagName, $this->CDATAEncoding))? "]]></$tagName>" : "</$tagName>";
$nodeText .= "</$tagName>";
return $nodeText . PHP_EOL;
}
/**
* @desc Print channels
* @access private
* @return void
*/
private function printChannels()
{
//Start channel tag
switch ($this->version)
{
case RSS2:
echo '<channel>' . PHP_EOL;
// add hubs
foreach ($this->hubs as $hub) {
//echo $this->makeNode('link', '', array('rel'=>'hub', 'href'=>$hub, 'xmlns'=>'http://www.w3.org/2005/Atom'));
echo '<link rel="hub" href="'.htmlspecialchars($hub).'" xmlns="http://www.w3.org/2005/Atom" />' . PHP_EOL;
}
// add self
if (isset($this->self)) {
//echo $this->makeNode('link', '', array('rel'=>'self', 'href'=>$this->self, 'xmlns'=>'http://www.w3.org/2005/Atom'));
echo '<link rel="self" href="'.htmlspecialchars($this->self).'" xmlns="http://www.w3.org/2005/Atom" />' . PHP_EOL;
}
break;
case RSS1:
echo (isset($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 $this->makeNode('id',$this->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 $this->endItem();
}
}
/**
* Make the starting tag of channels
*
* @access private
* @param srting The vale of about tag which is used for only RSS 1.0
* @return void
*/
private function startItem($about = false)
{
if($this->version == RSS2)
{
echo '<item>' . PHP_EOL;
}
elseif($this->version == RSS1)
{
if($about)
{
echo "<item rdf:about=\"$about\">" . PHP_EOL;
}
else
{
die('link element is not set .\n It\'s required for RSS 1.0 to be used as about attribute of item');
}
}
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;
}
}
// End # private functions ----------------------------------------------
} // end of class FeedWriter