WordPress/wp-includes/rss.php

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<?php
/**
* MagpieRSS: a simple RSS integration tool
*
* A compiled file for RSS syndication
*
* @author Kellan Elliott-McCrea <kellan@protest.net>
* @version 0.51
* @license GPL
*
* @package External
* @subpackage MagpieRSS
*/
/*
* Hook to use another RSS object instead of MagpieRSS
*/
do_action('load_feed_engine');
/** RSS feed constant. */
define('RSS', 'RSS');
define('ATOM', 'Atom');
define('MAGPIE_USER_AGENT', 'WordPress/' . $GLOBALS['wp_version']);
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;
// parser variables
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;
//var $ERROR = "";
var $_CONTENT_CONSTRUCTS = array('content', 'summary', 'info', 'title', 'tagline', 'copyright');
function MagpieRSS ($source) {
# if PHP xml isn't compiled in, die
#
if ( !function_exists('xml_parser_create') )
trigger_error( "Failed to load PHP's XML Extension. http://www.php.net/manual/en/ref.xml.php" );
$parser = @xml_parser_create();
if ( !is_resource($parser) )
trigger_error( "Failed to create an instance of PHP's XML parser. http://www.php.net/manual/en/ref.xml.php");
$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
$attrs_str = join(' ',
array_map(array('MagpieRSS', 'map_attrs'),
array_keys($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['descripton'] = $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'];
$this->items[$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'];
$this->items[$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 $this->feed_version;
}
else {
return false;
}
}
function map_attrs($k, $v) {
return "$k=\"$v\"";
}
function error( $errormsg, $lvl = E_USER_WARNING ) {
// append PHP's error message if track_errors enabled
if ( isset($php_errormsg) ) {
$errormsg .= " ($php_errormsg)";
}
if ( MAGPIE_DEBUG ) {
trigger_error( $errormsg, $lvl);
} else {
error_log( $errormsg, 0);
}
}
}
if ( !function_exists('fetch_rss') ) :
/**
* Build Magpie object based on RSS from URL.
*
* @since unknown
* @package External
* @subpackage MagpieRSS
*
* @param string $url URL to retrieve feed
* @return bool|MagpieRSS false on failure or MagpieRSS object on success.
*/
function fetch_rss ($url) {
// initialize constants
init();
if ( !isset($url) ) {
// error("fetch_rss called without a url");
return false;
}
// if cache is disabled
if ( !MAGPIE_CACHE_ON ) {
// fetch file, and parse it
$resp = _fetch_remote_file( $url );
if ( is_success( $resp->status ) ) {
return _response_to_rss( $resp );
}
else {
// error("Failed to fetch $url and cache is off");
return false;
}
}
// else cache is ON
else {
// Flow
// 1. check cache
// 2. if there is a hit, make sure its fresh
// 3. if cached obj fails freshness check, fetch remote
// 4. if remote fails, return stale object, or error
$cache = new RSSCache( MAGPIE_CACHE_DIR, MAGPIE_CACHE_AGE );
if (MAGPIE_DEBUG and $cache->ERROR) {
debug($cache->ERROR, E_USER_WARNING);
}
$cache_status = 0; // response of check_cache
$request_headers = array(); // HTTP headers to send with fetch
$rss = 0; // parsed RSS object
$errormsg = 0; // errors, if any
if (!$cache->ERROR) {
// return cache HIT, MISS, or STALE
$cache_status = $cache->check_cache( $url );
}
// if object cached, and cache is fresh, return cached obj
if ( $cache_status == 'HIT' ) {
$rss = $cache->get( $url );
if ( isset($rss) and $rss ) {
$rss->from_cache = 1;
if ( MAGPIE_DEBUG > 1) {
debug("MagpieRSS: Cache HIT", E_USER_NOTICE);
}
return $rss;
}
}
// else attempt a conditional get
// setup headers
if ( $cache_status == 'STALE' ) {
$rss = $cache->get( $url );
if ( isset($rss->etag) and $rss->last_modified ) {
$request_headers['If-None-Match'] = $rss->etag;
$request_headers['If-Last-Modified'] = $rss->last_modified;
}
}
$resp = _fetch_remote_file( $url, $request_headers );
if (isset($resp) and $resp) {
if ($resp->status == '304' ) {
// we have the most current copy
if ( MAGPIE_DEBUG > 1) {
debug("Got 304 for $url");
}
// reset cache on 304 (at minutillo insistent prodding)
$cache->set($url, $rss);
return $rss;
}
elseif ( is_success( $resp->status ) ) {
$rss = _response_to_rss( $resp );
if ( $rss ) {
if (MAGPIE_DEBUG > 1) {
debug("Fetch successful");
}
// add object to cache
$cache->set( $url, $rss );
return $rss;
}
}
else {
$errormsg = "Failed to fetch $url. ";
if ( $resp->error ) {
# compensate for Snoopy's annoying habbit to tacking
# on '\n'
$http_error = substr($resp->error, 0, -2);
$errormsg .= "(HTTP Error: $http_error)";
}
else {
$errormsg .= "(HTTP Response: " . $resp->response_code .')';
}
}
}
else {
$errormsg = "Unable to retrieve RSS file for unknown reasons.";
}
// else fetch failed
// attempt to return cached object
if ($rss) {
if ( MAGPIE_DEBUG ) {
debug("Returning STALE object for $url");
}
return $rss;
}
// else we totally failed
// error( $errormsg );
return false;
} // end if ( !MAGPIE_CACHE_ON ) {
} // end fetch_rss()
endif;
/**
* Retrieve URL headers and content using WP HTTP Request API.
*
* @since unknown
* @package External
* @subpackage MagpieRSS
*
* @param string $url URL to retrieve
* @param array $headers Optional. Headers to send to the URL.
* @return Snoopy style response
*/
function _fetch_remote_file ($url, $headers = "" ) {
$resp = wp_remote_request($url, array('headers' => $headers, 'timeout' => MAGPIE_FETCH_TIME_OUT));
if ( is_wp_error($resp) ) {
$error = array_shift($resp->errors);
$resp = new stdClass;
$resp->status = 500;
$resp->response_code = 500;
$resp->error = $error[0] . "\n"; //\n = Snoopy compatibility
return $resp;
}
$response = new stdClass;
$response->status = $resp['response']['code'];
$response->response_code = $resp['response']['code'];
$response->headers = $resp['headers'];
$response->results = $resp['body'];
return $response;
}
/**
* Retrieve
*
* @since unknown
* @package External
* @subpackage MagpieRSS
*
* @param unknown_type $resp
* @return unknown
*/
function _response_to_rss ($resp) {
$rss = new MagpieRSS( $resp->results );
// if RSS parsed successfully
if ( $rss && (!isset($rss->ERROR) || !$rss->ERROR) ) {
// find Etag, and Last-Modified
foreach( (array) $resp->headers as $h) {
// 2003-03-02 - Nicola Asuni (www.tecnick.com) - fixed bug "Undefined offset: 1"
if (strpos($h, ": ")) {
list($field, $val) = explode(": ", $h, 2);
}
else {
$field = $h;
$val = "";
}
if ( $field == 'ETag' ) {
$rss->etag = $val;
}
if ( $field == 'Last-Modified' ) {
$rss->last_modified = $val;
}
}
return $rss;
} // else construct error message
else {
$errormsg = "Failed to parse RSS file.";
if ($rss) {
$errormsg .= " (" . $rss->ERROR . ")";
}
// error($errormsg);
return false;
} // end if ($rss and !$rss->error)
}
/**
* Setup constants with default values, unless user overrides.
*
* @since unknown
* @package External
* @subpackage MagpieRSS
*/
function init () {
if ( defined('MAGPIE_INITALIZED') ) {
return;
}
else {
define('MAGPIE_INITALIZED', 1);
}
if ( !defined('MAGPIE_CACHE_ON') ) {
define('MAGPIE_CACHE_ON', 1);
}
if ( !defined('MAGPIE_CACHE_DIR') ) {
define('MAGPIE_CACHE_DIR', './cache');
}
if ( !defined('MAGPIE_CACHE_AGE') ) {
define('MAGPIE_CACHE_AGE', 60*60); // one hour
}
if ( !defined('MAGPIE_CACHE_FRESH_ONLY') ) {
define('MAGPIE_CACHE_FRESH_ONLY', 0);
}
if ( !defined('MAGPIE_DEBUG') ) {
define('MAGPIE_DEBUG', 0);
}
if ( !defined('MAGPIE_USER_AGENT') ) {
$ua = 'WordPress/' . $GLOBALS['wp_version'];
if ( MAGPIE_CACHE_ON ) {
$ua = $ua . ')';
}
else {
$ua = $ua . '; No cache)';
}
define('MAGPIE_USER_AGENT', $ua);
}
if ( !defined('MAGPIE_FETCH_TIME_OUT') ) {
define('MAGPIE_FETCH_TIME_OUT', 2); // 2 second timeout
}
// use gzip encoding to fetch rss files if supported?
if ( !defined('MAGPIE_USE_GZIP') ) {
define('MAGPIE_USE_GZIP', true);
}
}
function is_info ($sc) {
return $sc >= 100 && $sc < 200;
}
function is_success ($sc) {
return $sc >= 200 && $sc < 300;
}
function is_redirect ($sc) {
return $sc >= 300 && $sc < 400;
}
function is_error ($sc) {
return $sc >= 400 && $sc < 600;
}
function is_client_error ($sc) {
return $sc >= 400 && $sc < 500;
}
function is_server_error ($sc) {
return $sc >= 500 && $sc < 600;
}
class RSSCache {
var $BASE_CACHE; // where the cache files are stored
var $MAX_AGE = 43200; // when are files stale, default twelve hours
var $ERROR = ''; // accumulate error messages
function RSSCache ($base='', $age='') {
$this->BASE_CACHE = WP_CONTENT_DIR . '/cache';
if ( $base ) {
$this->BASE_CACHE = $base;
}
if ( $age ) {
$this->MAX_AGE = $age;
}
}
/*=======================================================================*\
Function: set
Purpose: add an item to the cache, keyed on url
Input: url from wich the rss file was fetched
Output: true on sucess
\*=======================================================================*/
function set ($url, $rss) {
global $wpdb;
$cache_option = 'rss_' . $this->file_name( $url );
set_transient($cache_option, $rss, $this->MAX_AGE);
return $cache_option;
}
/*=======================================================================*\
Function: get
Purpose: fetch an item from the cache
Input: url from wich the rss file was fetched
Output: cached object on HIT, false on MISS
\*=======================================================================*/
function get ($url) {
$this->ERROR = "";
$cache_option = 'rss_' . $this->file_name( $url );
if ( ! $rss = get_transient( $cache_option ) ) {
$this->debug(
"Cache doesn't contain: $url (cache option: $cache_option)"
);
return 0;
}
return $rss;
}
/*=======================================================================*\
Function: check_cache
Purpose: check a url for membership in the cache
and whether the object is older then MAX_AGE (ie. STALE)
Input: url from wich the rss file was fetched
Output: cached object on HIT, false on MISS
\*=======================================================================*/
function check_cache ( $url ) {
$this->ERROR = "";
$cache_option = 'rss_' . $this->file_name( $url );
if ( get_transient($cache_option) ) {
// object exists and is current
return 'HIT';
} else {
// object does not exist
return 'MISS';
}
}
/*=======================================================================*\
Function: serialize
\*=======================================================================*/
function serialize ( $rss ) {
return serialize( $rss );
}
/*=======================================================================*\
Function: unserialize
\*=======================================================================*/
function unserialize ( $data ) {
return unserialize( $data );
}
/*=======================================================================*\
Function: file_name
Purpose: map url to location in cache
Input: url from wich the rss file was fetched
Output: a file name
\*=======================================================================*/
function file_name ($url) {
return md5( $url );
}
/*=======================================================================*\
Function: error
Purpose: register error
\*=======================================================================*/
function error ($errormsg, $lvl=E_USER_WARNING) {
// append PHP's error message if track_errors enabled
if ( isset($php_errormsg) ) {
$errormsg .= " ($php_errormsg)";
}
$this->ERROR = $errormsg;
if ( MAGPIE_DEBUG ) {
trigger_error( $errormsg, $lvl);
}
else {
error_log( $errormsg, 0);
}
}
function debug ($debugmsg, $lvl=E_USER_NOTICE) {
if ( MAGPIE_DEBUG ) {
$this->error("MagpieRSS [debug] $debugmsg", $lvl);
}
}
}
if ( !function_exists('parse_w3cdtf') ) :
function parse_w3cdtf ( $date_str ) {
# regex to match wc3dtf
$pat = "/(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2})(:(\d{2}))?(?:([-+])(\d{2}):?(\d{2})|(Z))?/";
if ( preg_match( $pat, $date_str, $match ) ) {
list( $year, $month, $day, $hours, $minutes, $seconds) =
array( $match[1], $match[2], $match[3], $match[4], $match[5], $match[7]);
# calc epoch for current date assuming GMT
$epoch = gmmktime( $hours, $minutes, $seconds, $month, $day, $year);
$offset = 0;
if ( $match[11] == 'Z' ) {
# zulu time, aka GMT
}
else {
list( $tz_mod, $tz_hour, $tz_min ) =
array( $match[8], $match[9], $match[10]);
# zero out the variables
if ( ! $tz_hour ) { $tz_hour = 0; }
if ( ! $tz_min ) { $tz_min = 0; }
$offset_secs = (($tz_hour*60)+$tz_min)*60;
# is timezone ahead of GMT? then subtract offset
#
if ( $tz_mod == '+' ) {
$offset_secs = $offset_secs * -1;
}
$offset = $offset_secs;
}
$epoch = $epoch + $offset;
return $epoch;
}
else {
return -1;
}
}
endif;
if ( !function_exists('wp_rss') ) :
/**
* Display all RSS items in a HTML ordered list.
*
* @since unknown
* @package External
* @subpackage MagpieRSS
*
* @param string $url URL of feed to display. Will not auto sense feed URL.
* @param int $num_items Optional. Number of items to display, default is all.
*/
function wp_rss( $url, $num_items = -1 ) {
if ( $rss = fetch_rss( $url ) ) {
echo '<ul>';
if ( $num_items !== -1 ) {
$rss->items = array_slice( $rss->items, 0, $num_items );
}
foreach ( (array) $rss->items as $item ) {
printf(
'<li><a href="%1$s" title="%2$s">%3$s</a></li>',
clean_url( $item['link'] ),
attribute_escape( strip_tags( $item['description'] ) ),
htmlentities( $item['title'] )
);
}
echo '</ul>';
} else {
_e( 'An error has occurred, which probably means the feed is down. Try again later.' );
}
}
endif;
if ( !function_exists('get_rss') ) :
/**
* Display RSS items in HTML list items.
*
* You have to specify which HTML list you want, either ordered or unordered
* before using the function. You also have to specify how many items you wish
* to display. You can't display all of them like you can with wp_rss()
* function.
*
* @since unknown
* @package External
* @subpackage MagpieRSS
*
* @param string $url URL of feed to display. Will not auto sense feed URL.
* @param int $num_items Optional. Number of items to display, default is all.
* @return bool False on failure.
*/
function get_rss ($url, $num_items = 5) { // Like get posts, but for RSS
$rss = fetch_rss($url);
if ( $rss ) {
$rss->items = array_slice($rss->items, 0, $num_items);
foreach ( (array) $rss->items as $item ) {
echo "<li>\n";
echo "<a href='$item[link]' title='$item[description]'>";
echo htmlentities($item['title']);
echo "</a><br />\n";
echo "</li>\n";
}
} else {
return false;
}
}
endif;
?>