<?php
# -- BEGIN LICENSE BLOCK ----------------------------------
#
# This file is part of Clearbricks.
#
# Copyright (c) 2003-2008 Olivier Meunier and contributors
# Licensed under the GPL version 2.0 license.
# See LICENSE file or
# http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
#
# -- END LICENSE BLOCK ------------------------------------

/**
* Feed parser
*
* This class can read RSS 1.0, RSS 2.0, Atom 0.3 and Atom 1.0 feeds. Works with
* {@link feedReader}
*
* @package Clearbricks
* @subpackage Feeds
*
* @author Florent Cotton
* @author Olivier Meunier
*/
class feedParser
{
	/** @var string Feed type */					public $feed_type;
	
	/** @var string Feed title */					public $title;
	/** @var string Feed link */					public $link;
	/** @var string Feed description */			public $description;
	/** @var string Feed publication date */		public $pubdate;
	/** @var string Feed generator */				public $generator;
	
	/** @var array Feed items */					public $items = array();
	
	/** @var SimpleXMLElement Feed XML content */	protected $xml;
	
	
	/**
	* Constructor.
	*
	* Takes some <var>$data</var> as input. Returns false if data is
	* not a valid XML stream. If everything's fine, feed is parsed and items
	* are in {@link $items} property.
	*
	* @param string	$data			XML stream
	*/
	public function __construct($data)
	{
		$this->xml = @simplexml_load_string($data);
		
		if (!$this->xml) {
			return false;
		}
		
		if (preg_match('/<rdf:RDF/', $data)) {
			$this->parseRSSRDF();
		} elseif (preg_match('/<rss/', $data)) {
			$this->parseRSS();
		} elseif (preg_match('!www.w3.org/2005/Atom!', $data)) {
			$this->parseAtom10();
		} else {
			$this->parseAtom03();
		}
		
		unset($data);
		unset($this->xml);
	}
	
	/**
	* RSS 1.0 parser.
	*/
	protected function parseRSSRDF()
	{
		$this->feed_type = 'rss 1.0 (rdf)';
		
		$this->title = (string) $this->xml->channel->title;
		$this->link = (string) $this->xml->channel->link;
		$this->description = (string) $this->xml->channel->description;
		$this->pubdate = (string) $this->xml->channel->children('http://purl.org/dc/elements/1.1/')->date;
		
		# Feed generator agent
		$g = $this->xml->channel->children('http://webns.net/mvcb/')->generatorAgent;
		if ($g) {
			$g = $g->attributes('http://www.w3.org/1999/02/22-rdf-syntax-ns#');
			$this->generator = (string) $g['resource'];
		}
		
		if (empty($this->xml->item)) {
			return;
		}
		
		foreach ($this->xml->item as $i)
		{
			$item = new stdClass();
			$item->title = (string) $i->title;
			$item->link = (string) $i->link;
			$item->creator = (string) $i->children('http://purl.org/dc/elements/1.1/')->creator;
			$item->description = (string) $i->description;
			$item->content = (string) $i->children('http://purl.org/rss/1.0/modules/content/')->encoded;
			$item->subject = $this->nodes2array($i->children('http://purl.org/dc/elements/1.1/')->subject);
			$item->pubdate = (string) $i->children('http://purl.org/dc/elements/1.1/')->date;
			$item->TS = strtotime($item->pubdate);
			
			$item->guid = (string) $item->link;
			if (!empty($i->attributes('http://www.w3.org/1999/02/22-rdf-syntax-ns#')->about)) {
				$item->guid = (string) $i->attributes('http://www.w3.org/1999/02/22-rdf-syntax-ns#')->about;
			}
			
			$this->items[] = $item;
		}
	}
	
	/**
	* RSS 2.0 parser
	*/
	protected function parseRSS()
	{
		$this->feed_type = 'rss '.$this->xml['version'];
		
		$this->title = (string) $this->xml->channel->title;
		$this->link = (string) $this->xml->channel->link;
		$this->description = (string) $this->xml->channel->description;
		$this->pubdate = (string) $this->xml->channel->pubDate;
		
		$this->generator = (string) $this->xml->channel->generator;
		
		if (empty($this->xml->channel->item)) {
			return;
		}
		
		foreach ($this->xml->channel->item as $i)
		{
			$item = new stdClass();
			$item->title = (string) $i->title;
			$item->link = (string) $i->link;
			$item->creator = (string) $i->children('http://purl.org/dc/elements/1.1/')->creator;
			$item->description = (string) $i->description;
			$item->content = (string) $i->children('http://purl.org/rss/1.0/modules/content/')->encoded;
			
			$item->subject = array_merge(
				$this->nodes2array($i->children('http://purl.org/dc/elements/1.1/')->subject),
				$this->nodes2array($i->category)
			);
			
			$item->pubdate = (string) $i->pubDate;
			if (!$item->pubdate && !empty($i->children('http://purl.org/dc/elements/1.1/')->date)) {
				$item->pubdate = (string) $i->children('http://purl.org/dc/elements/1.1/')->date;
			}
			
			$item->TS = strtotime($item->pubdate);
			
			$item->guid = (string) $item->link;
			if (!empty($i->guid)) {
				$item->guid = (string) $i->guid;
			}
			
			$this->items[] = $item;
		}
	}
	
	/**
	* Atom 0.3 parser
	*/
	protected function parseAtom03()
	{
		$this->feed_type = 'atom 0.3';
		
		$this->title = (string) $this->xml->title;
		$this->description = (string) $this->xml->subtitle;
		$this->pubdate = (string) $this->xml->modified;
		
		$this->generator = (string) $this->xml->generator;
		
		foreach ($this->xml->link as $link)
		{
			if ($link['rel'] == 'alternate' &&
				($link['type'] == 'text/html' || $link['type'] == 'application/xhtml+xml')) {
				$this->link = (string) $link['href'];
				break;
			}
		}
		
		if (empty($this->xml->entry)) {
			return;
		}
		
		foreach ($this->xml->entry as $i)
		{
			$item = new stdClass();
			
			foreach ($i->link as $link)
			{
				if ($link['rel'] == 'alternate' &&
					($link['type'] == 'text/html' || $link['type'] == 'application/xhtml+xml')) {
					$item->link = (string) $link['href'];
					break;
				}
			}
			
			$item->title = (string) $i->title;
			$item->creator = (string) $i->author->name;
			$item->description = (string) $i->summary;
			$item->content = (string) $i->content;
			$item->subject = $this->nodes2array($i->children('http://purl.org/dc/elements/1.1/')->subject);
			$item->pubdate = (string) $i->modified;
			$item->TS = strtotime($item->pubdate);
			
			$this->items[] = $item;
		}
	}
	
	/**
	* Atom 1.0 parser
	*/
	protected function parseAtom10()
	{
		$this->feed_type = 'atom 1.0';
		
		$this->title = (string) $this->xml->title;
		$this->description = (string) $this->xml->subtitle;
		$this->pubdate = (string) $this->xml->updated;
		
		$this->generator = (string) $this->xml->generator;
		
		foreach ($this->xml->link as $link)
		{
			if ($link['rel'] == 'alternate' &&
				($link['type'] == 'text/html' || $link['type'] == 'application/xhtml+xml')) {
				$this->link = (string) $link['href'];
				break;
			}
		}
		
		if (empty($this->xml->entry)) {
			return;
		}
		
		foreach ($this->xml->entry as $i)
		{
			$item = new stdClass();
			
			foreach ($i->link as $link)
			{
				if ($link['rel'] == 'alternate' &&
					($link['type'] == 'text/html' || $link['type'] == 'application/xhtml+xml')) {
					$item->link = (string) $link['href'];
					break;
				}
			}
			
			$item->title = (string) $i->title;
			$item->creator = (string) $i->author->name;
			$item->description = (string) $i->summary;
			$item->content = (string) $i->content;
			$item->subject = $this->nodes2array($i->children('http://purl.org/dc/elements/1.1/')->subject);
			$item->pubdate = !empty($i->published) ? (string) $i->published : (string) $i->updated;
			$item->TS = strtotime($item->pubdate);
			
			$this->items[] = $item;
		}
	}
	
	/**
	* SimpleXML to array
	*
	* Converts a SimpleXMLElement to an array.
	*
	* @param SimpleXMLElement	$node	SimpleXML Node
	* @return array
	*/
	protected function nodes2array(&$nodes)
	{
		if (empty($nodes)) {
			return array();
		}
		
		$res = array();
		foreach ($nodes as $v)
		{
			$res[] = (string) $v;
		}
		
		return $res;
	}
}
?>