<?php
/**
* Project: MagpieRSS: a simple RSS integration tool
* File: rss_parse.inc - parse an RSS or Atom feed
* return as a simple object.
*
* Handles RSS 0.9x, RSS 2.0, RSS 1.0, and Atom 0.3
*
* The lastest version of MagpieRSS can be obtained from:
* http://magpierss.sourceforge.net
*
* For questions, help, comments, discussion, etc., please join the
* Magpie mailing list:
* magpierss-general@lists.sourceforge.net
*
* @author Kellan Elliott-McCrea <kellan@protest.net>
* @version 0.7a
* @license GPL
*
*/
define('RSS', 'RSS');
define('ATOM', 'Atom');
require_once (MAGPIE_DIR . 'Utils.inc');
/**
* Hybrid parser, and object, takes RSS as a string and returns a simple object.
*
* see: rss_fetch.inc for a simpler interface with integrated caching support
*
*/
class MagpieRSS {
var $parser;
var $current_item = array(); // item currently being parsed
var $items = array(); // collection of parsed items
var $channel = array(); // hash of channel fields
var $textinput = array();
var $image = array();
var $feed_type;
var $feed_version;
var $encoding = ''; // output encoding of parsed rss
var $_source_encoding = ''; // only set if we have to parse xml prolog
var $ERROR = "";
var $WARNING = "";
// define some constants
var $_CONTENT_CONSTRUCTS = array('content', 'summary', 'info', 'title', 'tagline', 'copyright');
var $_KNOWN_ENCODINGS = array('UTF-8', 'US-ASCII', 'ISO-8859-1');
// parser variables, useless if you're not a parser, treat as private
var $stack = array(); // parser stack
var $inchannel = false;
var $initem = false;
var $incontent = false; // if in Atom <content mode="xml"> field
var $intextinput = false;
var $inimage = false;
var $current_field = '';
var $current_namespace = false;
/**
* Set up XML parser, parse source, and return populated RSS object..
*
* @param string $source string containing the RSS to be parsed
*
* NOTE: Probably a good idea to leave the encoding options alone unless
* you know what you're doing as PHP's character set support is
* a little weird.
*
* NOTE: A lot of this is unnecessary but harmless with PHP5
*
*
* @param string $output_encoding output the parsed RSS in this character
* set defaults to ISO-8859-1 as this is PHP's
* default.
*
* NOTE: might be changed to UTF-8 in future
* versions.
*
* @param string $input_encoding the character set of the incoming RSS source.
* Leave blank and Magpie will try to figure it
* out.
*
*
* @param bool $detect_encoding if false Magpie won't attempt to detect
* source encoding. (caveat emptor)
*
*/
function MagpieRSS ($source, $output_encoding='UTF-8',
$input_encoding=null, $detect_encoding=true)
{
# if PHP xml isn't compiled in, die
#
if (!function_exists('xml_parser_create')) {
$this->error( "Failed to load PHP's XML Extension. " .
"http://www.php.net/manual/en/ref.xml.php",
E_USER_ERROR );
}
list($parser, $source) = $this->create_parser($source,
$output_encoding, $input_encoding, $detect_encoding);
if (!is_resource($parser)) {
$this->error( "Failed to create an instance of PHP's XML parser. " .
"http://www.php.net/manual/en/ref.xml.php",
E_USER_ERROR );
}
$this->parser = $parser;
# pass in parser, and a reference to this object
# setup handlers
#
xml_set_object( $this->parser, $this );
xml_set_element_handler($this->parser,
'feed_start_element', 'feed_end_element' );
xml_set_character_data_handler( $this->parser, 'feed_cdata' );
$status = xml_parse( $this->parser, $source );
if (! $status ) {
$errorcode = xml_get_error_code( $this->parser );
if ( $errorcode != XML_ERROR_NONE ) {
$xml_error = xml_error_string( $errorcode );
$error_line = xml_get_current_line_number($this->parser);
$error_col = xml_get_current_column_number($this->parser);
$errormsg = "$xml_error at line $error_line, column $error_col";
$this->error( $errormsg );
}
}
xml_parser_free( $this->parser );
$this->normalize();
}
function feed_start_element($p, $element, &$attrs) {
$el = $element = strtolower($element);
$attrs = array_change_key_case($attrs, CASE_LOWER);
// check for a namespace, and split if found
$ns = false;
if ( strpos( $element, ':' ) ) {
list($ns, $el) = split( ':', $element, 2);
}
if ( $ns and $ns != 'rdf' ) {
$this->current_namespace = $ns;
}
# if feed type isn't set, then this is first element of feed
# identify feed from root element
#
if (!isset($this->feed_type) ) {
if ( $el == 'rdf' ) {
$this->feed_type = RSS;
$this->feed_version = '1.0';
}
elseif ( $el == 'rss' ) {
$this->feed_type = RSS;
$this->feed_version = $attrs['version'];
}
elseif ( $el == 'feed' ) {
$this->feed_type = ATOM;
$this->feed_version = $attrs['version'];
$this->inchannel = true;
}
return;
}
if ( $el == 'channel' )
{
$this->inchannel = true;
}
elseif ($el == 'item' or $el == 'entry' )
{
$this->initem = true;
if ( isset($attrs['rdf:about']) ) {
$this->current_item['about'] = $attrs['rdf:about'];
}
}
// if we're in the default namespace of an RSS feed,
// record textinput or image fields
elseif (
$this->feed_type == RSS and
$this->current_namespace == '' and
$el == 'textinput' )
{
$this->intextinput = true;
}
elseif (
$this->feed_type == RSS and
$this->current_namespace == '' and
$el == 'image' )
{
$this->inimage = true;
}
# handle atom content constructs
elseif ( $this->feed_type == ATOM and in_array($el, $this->_CONTENT_CONSTRUCTS) )
{
// avoid clashing w/ RSS mod_content
if ($el == 'content' ) {
$el = 'atom_content';
}
$this->incontent = $el;
}
// if inside an Atom content construct (e.g. content or summary) field treat tags as text
elseif ($this->feed_type == ATOM and $this->incontent )
{
// if tags are inlined, then flatten
$attrs_str = join(' ',
array_map('map_attrs',
array_keys($attrs),
array_values($attrs) ) );
$this->append_content( "<$element $attrs_str>" );
array_unshift( $this->stack, $el );
}
// Atom support many links per containging element.
// Magpie treats link elements of type rel='alternate'
// as being equivalent to RSS's simple link element.
//
elseif ($this->feed_type == ATOM and $el == 'link' )
{
if ( isset($attrs['rel']) and $attrs['rel'] == 'alternate' )
{
$link_el = 'link';
}
else {
$link_el = 'link_' . $attrs['rel'];
}
$this->append($link_el, $attrs['href']);
}
// set stack[0] to current element
else {
array_unshift($this->stack, $el);
}
}
function feed_cdata ($p, $text) {
if ($this->feed_type == ATOM and $this->incontent)
{
$this->append_content( $text );
}
else {
$current_el = join('_', array_reverse($this->stack));
$this->append($current_el, $text);
}
}
function feed_end_element ($p, $el) {
$el = strtolower($el);
if ( $el == 'item' or $el == 'entry' )
{
$this->items[] = $this->current_item;
$this->current_item = array();
$this->initem = false;
}
elseif ($this->feed_type == RSS and $this->current_namespace == '' and $el == 'textinput' )
{
$this->intextinput = false;
}
elseif ($this->feed_type == RSS and $this->current_namespace == '' and $el == 'image' )
{
$this->inimage = false;
}
elseif ($this->feed_type == ATOM and in_array($el, $this->_CONTENT_CONSTRUCTS) )
{
$this->incontent = false;
}
elseif ($el == 'channel' or $el == 'feed' )
{
$this->inchannel = false;
}
elseif ($this->feed_type == ATOM and $this->incontent ) {
// balance tags properly
// note: i don't think this is actually neccessary
if ( $this->stack[0] == $el )
{
$this->append_content("</$el>");
}
else {
$this->append_content("<$el />");
}
array_shift( $this->stack );
}
else {
array_shift( $this->stack );
}
$this->current_namespace = false;
}
function concat (&$str1, $str2="") {
if (!isset($str1) ) {
$str1="";
}
$str1 .= $str2;
}
function append_content($text) {
if ( $this->initem ) {
$this->concat( $this->current_item[ $this->incontent ], $text );
}
elseif ( $this->inchannel ) {
$this->concat( $this->channel[ $this->incontent ], $text );
}
}
// smart append - field and namespace aware
function append($el, $text) {
if (!$el) {
return;
}
if ( $this->current_namespace )
{
if ( $this->initem ) {
$this->concat(
$this->current_item[ $this->current_namespace ][ $el ], $text);
}
elseif ($this->inchannel) {
$this->concat(
$this->channel[ $this->current_namespace][ $el ], $text );
}
elseif ($this->intextinput) {
$this->concat(
$this->textinput[ $this->current_namespace][ $el ], $text );
}
elseif ($this->inimage) {
$this->concat(
$this->image[ $this->current_namespace ][ $el ], $text );
}
}
else {
if ( $this->initem ) {
$this->concat(
$this->current_item[ $el ], $text);
}
elseif ($this->intextinput) {
$this->concat(
$this->textinput[ $el ], $text );
}
elseif ($this->inimage) {
$this->concat(
$this->image[ $el ], $text );
}
elseif ($this->inchannel) {
$this->concat(
$this->channel[ $el ], $text );
}
}
}
function normalize () {
// if atom populate rss fields
if ( $this->is_atom() ) {
$this->channel['description'] = $this->channel['tagline'];
for ( $i = 0; $i < count($this->items); $i++) {
$item = $this->items[$i];
if ( isset($item['summary']) )
$item['description'] = $item['summary'];
if ( isset($item['atom_content']))
$item['content']['encoded'] = $item['atom_content'];
$atom_date = (isset($item['issued']) ) ? $item['issued'] : $item['modified'];
if ( $atom_date ) {
$epoch = @parse_w3cdtf($item['modified']);
if ($epoch and $epoch > 0) {
$item['date_timestamp'] = $epoch;
$item['date'] = $epoch; //kyndig
}
}
$this->items[$i] = $item;
}
}
elseif ( $this->is_rss() ) {
$this->channel['tagline'] = $this->channel['description'];
for ( $i = 0; $i < count($this->items); $i++) {
$item = $this->items[$i];
if ( isset($item['description']))
$item['summary'] = $item['description'];
if ( isset($item['content']['encoded'] ) )
$item['atom_content'] = $item['content']['encoded'];
if ( $this->is_rss() == '1.0' and isset($item['dc']['date']) ) {
$epoch = @parse_w3cdtf($item['dc']['date']);
if ($epoch and $epoch > 0) {
$item['date_timestamp'] = $epoch;
$item['date'] = $epoch; //kyndig
}
}
elseif ( isset($item['pubdate']) || isset($item['pubDate']) ) {
$epoch = @strtotime($item['pubdate']);
if ($epoch > 0) {
$item['date_timestamp'] = $epoch;
$item['date'] = $epoch; //kyndig
}
}
$this->items[$i] = $item;
}
}
}
function is_rss () {
if ( $this->feed_type == RSS ) {
return $this->feed_version;
}
else {
return false;
}
}
function is_atom() {
if ( $this->feed_type == ATOM ) {
return $this->feed_version;
}
else {
return false;
}
}
/**
* return XML parser, and possibly re-encoded source
*
*/
function create_parser($source, $out_enc, $in_enc, $detect) {
if ( substr(phpversion(),0,1) == 5) {
$parser = $this->php5_create_parser($in_enc, $detect);
}
else {
list($parser, $source) = $this->php4_create_parser($source, $in_enc, $detect);
}
if ($out_enc) {
$this->encoding = $out_enc;
xml_parser_set_option($parser, XML_OPTION_TARGET_ENCODING, $out_enc);
}
return array($parser, $source);
}
/**
* Instantiate an XML parser under PHP5
*
* PHP5 will do a fine job of detecting input encoding
* if passed an empty string as the encoding.
*
* All hail libxml2!
*
*/
function php5_create_parser($in_enc, $detect) {
// by default php5 does a fine job of detecting input encodings
if(!$detect && $in_enc) {
return xml_parser_create($in_enc);
}
else {
return xml_parser_create('');
}
}
/**
* Instaniate an XML parser under PHP4
*
* Unfortunately PHP4's support for character encodings
* and especially XML and character encodings sucks. As
* long as the documents you parse only contain characters
* from the ISO-8859-1 character set (a superset of ASCII,
* and a subset of UTF-8) you're fine. However once you
* step out of that comfy little world things get mad, bad,
* and dangerous to know.
*
* The following code is based on SJM's work with FoF
* @see http://minutillo.com/steve/weblog/2004/6/17/php-xml-and-character-encodings-a-tale-of-sadness-rage-and-data-loss
*
*/
function php4_create_parser($source, $in_enc, $detect) {
if ( !$detect ) {
return array(xml_parser_create($in_enc), $source);
}
if (!$in_enc) {
if (preg_match('/<?xml.*encoding=[\'"](.*?)[\'"].*?>/m', $source, $m)) {
$in_enc = strtoupper($m[1]);
$this->source_encoding = $in_enc;
}
else {
$in_enc = 'UTF-8';
}
}
if ($this->known_encoding($in_enc)) {
return array(xml_parser_create($in_enc), $source);
}
// the dectected encoding is not one of the simple encodings PHP knows
// attempt to use the iconv extension to
// cast the XML to a known encoding
// @see http://php.net/iconv
if (function_exists('iconv')) {
$encoded_source = iconv($in_enc,'UTF-8', $source);
if ($encoded_source) {
return array(xml_parser_create('UTF-8'), $encoded_source);
}
}
// iconv didn't work, try mb_convert_encoding
// @see http://php.net/mbstring
if(function_exists('mb_convert_encoding')) {
$encoded_source = mb_convert_encoding($source, 'UTF-8', $in_enc );
if ($encoded_source) {
return array(xml_parser_create('UTF-8'), $encoded_source);
}
}
// else
$this->error("Feed is in an unsupported character encoding. ($in_enc) " .
"You may see strange artifacts, and mangled characters.",
E_USER_NOTICE);
return array(xml_parser_create(), $source);
}
function known_encoding($enc) {
$enc = strtoupper($enc);
if ( in_array($enc, $this->_KNOWN_ENCODINGS) ) {
return $enc;
}
else {
return false;
}
}
function error ($errormsg, $lvl=E_USER_WARNING) {
// append PHP's error message if track_errors enabled
if ( !empty( $php_errormsg ) ) {
$errormsg .= " ($php_errormsg)";
}
if ( MAGPIE_DEBUG ) {
trigger_error( $errormsg, $lvl);
}
else {
error_log( $errormsg, 0);
}
$notices = E_USER_NOTICE|E_NOTICE;
if ( $lvl&$notices ) {
$this->WARNING = $errormsg;
} else {
$this->ERROR = $errormsg;
}
}
} // end class RSS
function map_attrs($k, $v) {
return "$k=\"$v\"";
}
?>
