wp-includes/rss-functions.php

   1 <?php
   2 /*
   3  * Project:     MagpieRSS: a simple RSS integration tool
   4  * File:        A compiled file for RSS syndication
   5  * Author:      Kellan Elliott-McCrea <kellan@protest.net>
   6  * Version:             0.51
   7  * License:             GPL
   8  */
   9
  10 define('RSS', 'RSS');
  11 define('ATOM', 'Atom');
  12 define('MAGPIE_USER_AGENT', 'WordPress/' . $wp_version);
  13
  14 class MagpieRSS {
  15         var $parser;
  16         var $current_item       = array();      // item currently being parsed
  17         var $items                      = array();      // collection of parsed items
  18         var $channel            = array();      // hash of channel fields
  19         var $textinput          = array();
  20         var $image                      = array();
  21         var $feed_type;
  22         var $feed_version;
  23
  24         // parser variables
  25         var $stack                              = array(); // parser stack
  26         var $inchannel                  = false;
  27         var $initem                     = false;
  28         var $incontent                  = false; // if in Atom <content mode="xml"> field
  29         var $intextinput                = false;
  30         var $inimage                    = false;
  31         var $current_field              = '';
  32         var $current_namespace  = false;
  33
  34         //var $ERROR = "";
  35
  36         var $_CONTENT_CONSTRUCTS = array('content', 'summary', 'info', 'title', 'tagline', 'copyright');
  37
  38         function MagpieRSS ($source) {
  39
  40                 # if PHP xml isn't compiled in, die
  41                 #
  42                 if ( !function_exists('xml_parser_create') )
  43                         trigger_error( "Failed to load PHP's XML Extension. http://www.php.net/manual/en/ref.xml.php" );
  44
  45                 $parser = @xml_parser_create();
  46
  47                 if ( !is_resource($parser) )
  48                         trigger_error( "Failed to create an instance of PHP's XML parser. http://www.php.net/manual/en/ref.xml.php");
  49
  50
  51                 $this->parser = $parser;
  52
  53                 # pass in parser, and a reference to this object
  54                 # setup handlers
  55                 #
  56                 xml_set_object( $this->parser, $this );
  57                 xml_set_element_handler($this->parser,
  58                                 'feed_start_element', 'feed_end_element' );
  59
  60                 xml_set_character_data_handler( $this->parser, 'feed_cdata' );
  61
  62                 $status = xml_parse( $this->parser, $source );
  63
  64                 if (! $status ) {
  65                         $errorcode = xml_get_error_code( $this->parser );
  66                         if ( $errorcode != XML_ERROR_NONE ) {
  67                                 $xml_error = xml_error_string( $errorcode );
  68                                 $error_line = xml_get_current_line_number($this->parser);
  69                                 $error_col = xml_get_current_column_number($this->parser);
  70                                 $errormsg = "$xml_error at line $error_line, column $error_col";
  71
  72                                 $this->error( $errormsg );
  73                         }
  74                 }
  75
  76                 xml_parser_free( $this->parser );
  77
  78                 $this->normalize();
  79         }
  80
  81         function feed_start_element($p, $element, &$attrs) {
  82                 $el = $element = strtolower($element);
  83                 $attrs = array_change_key_case($attrs, CASE_LOWER);
  84
  85                 // check for a namespace, and split if found
  86                 $ns     = false;
  87                 if ( strpos( $element, ':' ) ) {
  88                         list($ns, $el) = split( ':', $element, 2);
  89                 }
  90                 if ( $ns and $ns != 'rdf' ) {
  91                         $this->current_namespace = $ns;
  92                 }
  93
  94                 # if feed type isn't set, then this is first element of feed
  95                 # identify feed from root element
  96                 #
  97                 if (!isset($this->feed_type) ) {
  98                         if ( $el == 'rdf' ) {
  99                                 $this->feed_type = RSS;
 100                                 $this->feed_version = '1.0';
 101                         }
 102                         elseif ( $el == 'rss' ) {
 103                                 $this->feed_type = RSS;
 104                                 $this->feed_version = $attrs['version'];
 105                         }
 106                         elseif ( $el == 'feed' ) {
 107                                 $this->feed_type = ATOM;
 108                                 $this->feed_version = $attrs['version'];
 109                                 $this->inchannel = true;
 110                         }
 111                         return;
 112                 }
 113
 114                 if ( $el == 'channel' )
 115                 {
 116                         $this->inchannel = true;
 117                 }
 118                 elseif ($el == 'item' or $el == 'entry' )
 119                 {
 120                         $this->initem = true;
 121                         if ( isset($attrs['rdf:about']) ) {
 122                                 $this->current_item['about'] = $attrs['rdf:about'];
 123                         }
 124                 }
 125
 126                 // if we're in the default namespace of an RSS feed,
 127                 //  record textinput or image fields
 128                 elseif (
 129                         $this->feed_type == RSS and
 130                         $this->current_namespace == '' and
 131                         $el == 'textinput' )
 132                 {
 133                         $this->intextinput = true;
 134                 }
 135
 136                 elseif (
 137                         $this->feed_type == RSS and
 138                         $this->current_namespace == '' and
 139                         $el == 'image' )
 140                 {
 141                         $this->inimage = true;
 142                 }
 143
 144                 # handle atom content constructs
 145                 elseif ( $this->feed_type == ATOM and in_array($el, $this->_CONTENT_CONSTRUCTS) )
 146                 {
 147                         // avoid clashing w/ RSS mod_content
 148                         if ($el == 'content' ) {
 149                                 $el = 'atom_content';
 150                         }
 151
 152                         $this->incontent = $el;
 153
 154
 155                 }
 156
 157                 // if inside an Atom content construct (e.g. content or summary) field treat tags as text
 158                 elseif ($this->feed_type == ATOM and $this->incontent )
 159                 {
 160                         // if tags are inlined, then flatten
 161                         $attrs_str = join(' ',
 162                                         array_map('map_attrs',
 163                                         array_keys($attrs),
 164                                         array_values($attrs) ) );
 165
 166                         $this->append_content( "<$element $attrs_str>"  );
 167
 168                         array_unshift( $this->stack, $el );
 169                 }
 170
 171                 // Atom support many links per containging element.
 172                 // Magpie treats link elements of type rel='alternate'
 173                 // as being equivalent to RSS's simple link element.
 174                 //
 175                 elseif ($this->feed_type == ATOM and $el == 'link' )
 176                 {
 177                         if ( isset($attrs['rel']) and $attrs['rel'] == 'alternate' )
 178                         {
 179                                 $link_el = 'link';
 180                         }
 181                         else {
 182                                 $link_el = 'link_' . $attrs['rel'];
 183                         }
 184
 185                         $this->append($link_el, $attrs['href']);
 186                 }
 187                 // set stack[0] to current element
 188                 else {
 189                         array_unshift($this->stack, $el);
 190                 }
 191         }
 192
 193
 194
 195         function feed_cdata ($p, $text) {
 196
 197                 if ($this->feed_type == ATOM and $this->incontent)
 198                 {
 199                         $this->append_content( $text );
 200                 }
 201                 else {
 202                         $current_el = join('_', array_reverse($this->stack));
 203                         $this->append($current_el, $text);
 204                 }
 205         }
 206
 207         function feed_end_element ($p, $el) {
 208                 $el = strtolower($el);
 209
 210                 if ( $el == 'item' or $el == 'entry' )
 211                 {
 212                         $this->items[] = $this->current_item;
 213                         $this->current_item = array();
 214                         $this->initem = false;
 215                 }
 216                 elseif ($this->feed_type == RSS and $this->current_namespace == '' and $el == 'textinput' )
 217                 {
 218                         $this->intextinput = false;
 219                 }
 220                 elseif ($this->feed_type == RSS and $this->current_namespace == '' and $el == 'image' )
 221                 {
 222                         $this->inimage = false;
 223                 }
 224                 elseif ($this->feed_type == ATOM and in_array($el, $this->_CONTENT_CONSTRUCTS) )
 225                 {
 226                         $this->incontent = false;
 227                 }
 228                 elseif ($el == 'channel' or $el == 'feed' )
 229                 {
 230                         $this->inchannel = false;
 231                 }
 232                 elseif ($this->feed_type == ATOM and $this->incontent  ) {
 233                         // balance tags properly
 234                         // note:  i don't think this is actually neccessary
 235                         if ( $this->stack[0] == $el )
 236                         {
 237                                 $this->append_content("</$el>");
 238                         }
 239                         else {
 240                                 $this->append_content("<$el />");
 241                         }
 242
 243                         array_shift( $this->stack );
 244                 }
 245                 else {
 246                         array_shift( $this->stack );
 247                 }
 248
 249                 $this->current_namespace = false;
 250         }
 251
 252         function concat (&$str1, $str2="") {
 253                 if (!isset($str1) ) {
 254                         $str1="";
 255                 }
 256                 $str1 .= $str2;
 257         }
 258
 259         function append_content($text) {
 260                 if ( $this->initem ) {
 261                         $this->concat( $this->current_item[ $this->incontent ], $text );
 262                 }
 263                 elseif ( $this->inchannel ) {
 264                         $this->concat( $this->channel[ $this->incontent ], $text );
 265                 }
 266         }
 267
 268         // smart append - field and namespace aware
 269         function append($el, $text) {
 270                 if (!$el) {
 271                         return;
 272                 }
 273                 if ( $this->current_namespace )
 274                 {
 275                         if ( $this->initem ) {
 276                                 $this->concat(
 277                                         $this->current_item[ $this->current_namespace ][ $el ], $text);
 278                         }
 279                         elseif ($this->inchannel) {
 280                                 $this->concat(
 281                                         $this->channel[ $this->current_namespace][ $el ], $text );
 282                         }
 283                         elseif ($this->intextinput) {
 284                                 $this->concat(
 285                                         $this->textinput[ $this->current_namespace][ $el ], $text );
 286                         }
 287                         elseif ($this->inimage) {
 288                                 $this->concat(
 289                                         $this->image[ $this->current_namespace ][ $el ], $text );
 290                         }
 291                 }
 292                 else {
 293                         if ( $this->initem ) {
 294                                 $this->concat(
 295                                         $this->current_item[ $el ], $text);
 296                         }
 297                         elseif ($this->intextinput) {
 298                                 $this->concat(
 299                                         $this->textinput[ $el ], $text );
 300                         }
 301                         elseif ($this->inimage) {
 302                                 $this->concat(
 303                                         $this->image[ $el ], $text );
 304                         }
 305                         elseif ($this->inchannel) {
 306                                 $this->concat(
 307                                         $this->channel[ $el ], $text );
 308                         }
 309
 310                 }
 311         }
 312
 313         function normalize () {
 314                 // if atom populate rss fields
 315                 if ( $this->is_atom() ) {
 316                         $this->channel['descripton'] = $this->channel['tagline'];
 317                         for ( $i = 0; $i < count($this->items); $i++) {
 318                                 $item = $this->items[$i];
 319                                 if ( isset($item['summary']) )
 320                                         $item['description'] = $item['summary'];
 321                                 if ( isset($item['atom_content']))
 322                                         $item['content']['encoded'] = $item['atom_content'];
 323
 324                                 $this->items[$i] = $item;
 325                         }
 326                 }
 327                 elseif ( $this->is_rss() ) {
 328                         $this->channel['tagline'] = $this->channel['description'];
 329                         for ( $i = 0; $i < count($this->items); $i++) {
 330                                 $item = $this->items[$i];
 331                                 if ( isset($item['description']))
 332                                         $item['summary'] = $item['description'];
 333                                 if ( isset($item['content']['encoded'] ) )
 334                                         $item['atom_content'] = $item['content']['encoded'];
 335
 336                                 $this->items[$i] = $item;
 337                         }
 338                 }
 339         }
 340
 341         function is_rss () {
 342                 if ( $this->feed_type == RSS ) {
 343                         return $this->feed_version;
 344                 }
 345                 else {
 346                         return false;
 347                 }
 348         }
 349
 350         function is_atom() {
 351                 if ( $this->feed_type == ATOM ) {
 352                         return $this->feed_version;
 353                 }
 354                 else {
 355                         return false;
 356                 }
 357         }
 358
 359         function map_attrs($k, $v) {
 360                 return "$k=\"$v\"";
 361         }
 362
 363         function error( $errormsg, $lvl = E_USER_WARNING ) {
 364                 // append PHP's error message if track_errors enabled
 365                 if ( isset($php_errormsg) ) {
 366                         $errormsg .= " ($php_errormsg)";
 367                 }
 368                 if ( MAGPIE_DEBUG ) {
 369                         trigger_error( $errormsg, $lvl);
 370                 } else {
 371                         error_log( $errormsg, 0);
 372                 }
 373         }
 374
 375 }
 376 require_once( dirname(__FILE__) . '/class-snoopy.php');
 377
 378 function fetch_rss ($url) {
 379         // initialize constants
 380         init();
 381
 382         if ( !isset($url) ) {
 383                 // error("fetch_rss called without a url");
 384                 return false;
 385         }
 386
 387         // if cache is disabled
 388         if ( !MAGPIE_CACHE_ON ) {
 389                 // fetch file, and parse it
 390                 $resp = _fetch_remote_file( $url );
 391                 if ( is_success( $resp->status ) ) {
 392                         return _response_to_rss( $resp );
 393                 }
 394                 else {
 395                         // error("Failed to fetch $url and cache is off");
 396                         return false;
 397                 }
 398         }
 399         // else cache is ON
 400         else {
 401                 // Flow
 402                 // 1. check cache
 403                 // 2. if there is a hit, make sure its fresh
 404                 // 3. if cached obj fails freshness check, fetch remote
 405                 // 4. if remote fails, return stale object, or error
 406
 407                 $cache = new RSSCache( MAGPIE_CACHE_DIR, MAGPIE_CACHE_AGE );
 408
 409                 if (MAGPIE_DEBUG and $cache->ERROR) {
 410                         debug($cache->ERROR, E_USER_WARNING);
 411                 }
 412
 413
 414                 $cache_status    = 0;           // response of check_cache
 415                 $request_headers = array(); // HTTP headers to send with fetch
 416                 $rss                     = 0;           // parsed RSS object
 417                 $errormsg                = 0;           // errors, if any
 418
 419                 if (!$cache->ERROR) {
 420                         // return cache HIT, MISS, or STALE
 421                         $cache_status = $cache->check_cache( $url );
 422                 }
 423
 424                 // if object cached, and cache is fresh, return cached obj
 425                 if ( $cache_status == 'HIT' ) {
 426                         $rss = $cache->get( $url );
 427                         if ( isset($rss) and $rss ) {
 428                                 $rss->from_cache = 1;
 429                                 if ( MAGPIE_DEBUG > 1) {
 430                                 debug("MagpieRSS: Cache HIT", E_USER_NOTICE);
 431                         }
 432                                 return $rss;
 433                         }
 434                 }
 435
 436                 // else attempt a conditional get
 437
 438                 // setup headers
 439                 if ( $cache_status == 'STALE' ) {
 440                         $rss = $cache->get( $url );
 441                         if ( $rss->etag and $rss->last_modified ) {
 442                                 $request_headers['If-None-Match'] = $rss->etag;
 443                                 $request_headers['If-Last-Modified'] = $rss->last_modified;
 444                         }
 445                 }
 446
 447                 $resp = _fetch_remote_file( $url, $request_headers );
 448
 449                 if (isset($resp) and $resp) {
 450                         if ($resp->status == '304' ) {
 451                                 // we have the most current copy
 452                                 if ( MAGPIE_DEBUG > 1) {
 453                                         debug("Got 304 for $url");
 454                                 }
 455                                 // reset cache on 304 (at minutillo insistent prodding)
 456                                 $cache->set($url, $rss);
 457                                 return $rss;
 458                         }
 459                         elseif ( is_success( $resp->status ) ) {
 460                                 $rss = _response_to_rss( $resp );
 461                                 if ( $rss ) {
 462                                         if (MAGPIE_DEBUG > 1) {
 463                                                 debug("Fetch successful");
 464                                         }
 465                                         // add object to cache
 466                                         $cache->set( $url, $rss );
 467                                         return $rss;
 468                                 }
 469                         }
 470                         else {
 471                                 $errormsg = "Failed to fetch $url. ";
 472                                 if ( $resp->error ) {
 473                                         # compensate for Snoopy's annoying habbit to tacking
 474                                         # on '\n'
 475                                         $http_error = substr($resp->error, 0, -2);
 476                                         $errormsg .= "(HTTP Error: $http_error)";
 477                                 }
 478                                 else {
 479                                         $errormsg .=  "(HTTP Response: " . $resp->response_code .')';
 480                                 }
 481                         }
 482                 }
 483                 else {
 484                         $errormsg = "Unable to retrieve RSS file for unknown reasons.";
 485                 }
 486
 487                 // else fetch failed
 488
 489                 // attempt to return cached object
 490                 if ($rss) {
 491                         if ( MAGPIE_DEBUG ) {
 492                                 debug("Returning STALE object for $url");
 493                         }
 494                         return $rss;
 495                 }
 496
 497                 // else we totally failed
 498                 // error( $errormsg );
 499
 500                 return false;
 501
 502         } // end if ( !MAGPIE_CACHE_ON ) {
 503 } // end fetch_rss()
 504
 505 function _fetch_remote_file ($url, $headers = "" ) {
 506         // Snoopy is an HTTP client in PHP
 507         $client = new Snoopy();
 508         $client->agent = MAGPIE_USER_AGENT;
 509         $client->read_timeout = MAGPIE_FETCH_TIME_OUT;
 510         $client->use_gzip = MAGPIE_USE_GZIP;
 511         if (is_array($headers) ) {
 512                 $client->rawheaders = $headers;
 513         }
 514
 515         @$client->fetch($url);
 516         return $client;
 517
 518 }
 519
 520 function _response_to_rss ($resp) {
 521         $rss = new MagpieRSS( $resp->results );
 522
 523         // if RSS parsed successfully
 524         if ( $rss and !$rss->ERROR) {
 525
 526                 // find Etag, and Last-Modified
 527                 foreach($resp->headers as $h) {
 528                         // 2003-03-02 - Nicola Asuni (www.tecnick.com) - fixed bug "Undefined offset: 1"
 529                         if (strpos($h, ": ")) {
 530                                 list($field, $val) = explode(": ", $h, 2);
 531                         }
 532                         else {
 533                                 $field = $h;
 534                                 $val = "";
 535                         }
 536
 537                         if ( $field == 'ETag' ) {
 538                                 $rss->etag = $val;
 539                         }
 540
 541                         if ( $field == 'Last-Modified' ) {
 542                                 $rss->last_modified = $val;
 543                         }
 544                 }
 545
 546                 return $rss;
 547         } // else construct error message
 548         else {
 549                 $errormsg = "Failed to parse RSS file.";
 550
 551                 if ($rss) {
 552                         $errormsg .= " (" . $rss->ERROR . ")";
 553                 }
 554                 // error($errormsg);
 555
 556                 return false;
 557         } // end if ($rss and !$rss->error)
 558 }
 559
 560 /*=======================================================================*\
 561         Function:       init
 562         Purpose:        setup constants with default values
 563                                 check for user overrides
 564 \*=======================================================================*/
 565 function init () {
 566         if ( defined('MAGPIE_INITALIZED') ) {
 567                 return;
 568         }
 569         else {
 570                 define('MAGPIE_INITALIZED', 1);
 571         }
 572
 573         if ( !defined('MAGPIE_CACHE_ON') ) {
 574                 define('MAGPIE_CACHE_ON', 1);
 575         }
 576
 577         if ( !defined('MAGPIE_CACHE_DIR') ) {
 578                 define('MAGPIE_CACHE_DIR', './cache');
 579         }
 580
 581         if ( !defined('MAGPIE_CACHE_AGE') ) {
 582                 define('MAGPIE_CACHE_AGE', 60*60); // one hour
 583         }
 584
 585         if ( !defined('MAGPIE_CACHE_FRESH_ONLY') ) {
 586                 define('MAGPIE_CACHE_FRESH_ONLY', 0);
 587         }
 588
 589                 if ( !defined('MAGPIE_DEBUG') ) {
 590                 define('MAGPIE_DEBUG', 0);
 591         }
 592
 593         if ( !defined('MAGPIE_USER_AGENT') ) {
 594                 $ua = 'WordPress/' . $wp_version;
 595
 596                 if ( MAGPIE_CACHE_ON ) {
 597                         $ua = $ua . ')';
 598                 }
 599                 else {
 600                         $ua = $ua . '; No cache)';
 601                 }
 602
 603                 define('MAGPIE_USER_AGENT', $ua);
 604         }
 605
 606         if ( !defined('MAGPIE_FETCH_TIME_OUT') ) {
 607                 define('MAGPIE_FETCH_TIME_OUT', 2);     // 2 second timeout
 608         }
 609
 610         // use gzip encoding to fetch rss files if supported?
 611         if ( !defined('MAGPIE_USE_GZIP') ) {
 612                 define('MAGPIE_USE_GZIP', true);
 613         }
 614 }
 615
 616 function is_info ($sc) {
 617         return $sc >= 100 && $sc < 200;
 618 }
 619
 620 function is_success ($sc) {
 621         return $sc >= 200 && $sc < 300;
 622 }
 623
 624 function is_redirect ($sc) {
 625         return $sc >= 300 && $sc < 400;
 626 }
 627
 628 function is_error ($sc) {
 629         return $sc >= 400 && $sc < 600;
 630 }
 631
 632 function is_client_error ($sc) {
 633         return $sc >= 400 && $sc < 500;
 634 }
 635
 636 function is_server_error ($sc) {
 637         return $sc >= 500 && $sc < 600;
 638 }
 639
 640 class RSSCache {
 641         var $BASE_CACHE = 'wp-content/cache';   // where the cache files are stored
 642         var $MAX_AGE    = 43200;                // when are files stale, default twelve hours
 643         var $ERROR              = '';                   // accumulate error messages
 644
 645         function RSSCache ($base='', $age='') {
 646                 if ( $base ) {
 647                         $this->BASE_CACHE = $base;
 648                 }
 649                 if ( $age ) {
 650                         $this->MAX_AGE = $age;
 651                 }
 652
 653         }
 654
 655 /*=======================================================================*\
 656         Function:       set
 657         Purpose:        add an item to the cache, keyed on url
 658         Input:          url from wich the rss file was fetched
 659         Output:         true on sucess
 660 \*=======================================================================*/
 661         function set ($url, $rss) {
 662                 global $wpdb;
 663                 $cache_option = 'rss_' . $this->file_name( $url );
 664                 $cache_timestamp = 'rss_' . $this->file_name( $url ) . '_ts';
 665
 666                 if ( !$wpdb->get_var("SELECT option_name FROM $wpdb->options WHERE option_name = '$cache_option'") )
 667                         add_option($cache_option, '', '', 'no');
 668                 if ( !$wpdb->get_var("SELECT option_name FROM $wpdb->options WHERE option_name = '$cache_timestamp'") )
 669                         add_option($cache_timestamp, '', '', 'no');
 670
 671                 update_option($cache_option, $rss);
 672                 update_option($cache_timestamp, time() );
 673
 674                 return $cache_option;
 675         }
 676
 677 /*=======================================================================*\
 678         Function:       get
 679         Purpose:        fetch an item from the cache
 680         Input:          url from wich the rss file was fetched
 681         Output:         cached object on HIT, false on MISS
 682 \*=======================================================================*/
 683         function get ($url) {
 684                 $this->ERROR = "";
 685                 $cache_option = 'rss_' . $this->file_name( $url );
 686
 687                 if ( ! get_option( $cache_option ) ) {
 688                         $this->debug(
 689                                 "Cache doesn't contain: $url (cache option: $cache_option)"
 690                         );
 691                         return 0;
 692                 }
 693
 694                 $rss = get_option( $cache_option );
 695
 696                 return $rss;
 697         }
 698
 699 /*=======================================================================*\
 700         Function:       check_cache
 701         Purpose:        check a url for membership in the cache
 702                                 and whether the object is older then MAX_AGE (ie. STALE)
 703         Input:          url from wich the rss file was fetched
 704         Output:         cached object on HIT, false on MISS
 705 \*=======================================================================*/
 706         function check_cache ( $url ) {
 707                 $this->ERROR = "";
 708                 $cache_option = $this->file_name( $url );
 709                 $cache_timestamp = 'rss_' . $this->file_name( $url ) . '_ts';
 710
 711                 if ( $mtime = get_option($cache_timestamp) ) {
 712                         // find how long ago the file was added to the cache
 713                         // and whether that is longer then MAX_AGE
 714                         $age = time() - $mtime;
 715                         if ( $this->MAX_AGE > $age ) {
 716                                 // object exists and is current
 717                                 return 'HIT';
 718                         }
 719                         else {
 720                                 // object exists but is old
 721                                 return 'STALE';
 722                         }
 723                 }
 724                 else {
 725                         // object does not exist
 726                         return 'MISS';
 727                 }
 728         }
 729
 730 /*=======================================================================*\
 731         Function:       serialize
 732 \*=======================================================================*/
 733         function serialize ( $rss ) {
 734                 return serialize( $rss );
 735         }
 736
 737 /*=======================================================================*\
 738         Function:       unserialize
 739 \*=======================================================================*/
 740         function unserialize ( $data ) {
 741                 return unserialize( $data );
 742         }
 743
 744 /*=======================================================================*\
 745         Function:       file_name
 746         Purpose:        map url to location in cache
 747         Input:          url from wich the rss file was fetched
 748         Output:         a file name
 749 \*=======================================================================*/
 750         function file_name ($url) {
 751                 return md5( $url );
 752         }
 753
 754 /*=======================================================================*\
 755         Function:       error
 756         Purpose:        register error
 757 \*=======================================================================*/
 758         function error ($errormsg, $lvl=E_USER_WARNING) {
 759                 // append PHP's error message if track_errors enabled
 760                 if ( isset($php_errormsg) ) {
 761                         $errormsg .= " ($php_errormsg)";
 762                 }
 763                 $this->ERROR = $errormsg;
 764                 if ( MAGPIE_DEBUG ) {
 765                         trigger_error( $errormsg, $lvl);
 766                 }
 767                 else {
 768                         error_log( $errormsg, 0);
 769                 }
 770         }
 771                         function debug ($debugmsg, $lvl=E_USER_NOTICE) {
 772                 if ( MAGPIE_DEBUG ) {
 773                         $this->error("MagpieRSS [debug] $debugmsg", $lvl);
 774                 }
 775         }
 776 }
 777
 778 function parse_w3cdtf ( $date_str ) {
 779
 780         # regex to match wc3dtf
 781         $pat = "/(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2})(:(\d{2}))?(?:([-+])(\d{2}):?(\d{2})|(Z))?/";
 782
 783         if ( preg_match( $pat, $date_str, $match ) ) {
 784                 list( $year, $month, $day, $hours, $minutes, $seconds) =
 785                         array( $match[1], $match[2], $match[3], $match[4], $match[5], $match[6]);
 786
 787                 # calc epoch for current date assuming GMT
 788                 $epoch = gmmktime( $hours, $minutes, $seconds, $month, $day, $year);
 789
 790                 $offset = 0;
 791                 if ( $match[10] == 'Z' ) {
 792                         # zulu time, aka GMT
 793                 }
 794                 else {
 795                         list( $tz_mod, $tz_hour, $tz_min ) =
 796                                 array( $match[8], $match[9], $match[10]);
 797
 798                         # zero out the variables
 799                         if ( ! $tz_hour ) { $tz_hour = 0; }
 800                         if ( ! $tz_min ) { $tz_min = 0; }
 801
 802                         $offset_secs = (($tz_hour*60)+$tz_min)*60;
 803
 804                         # is timezone ahead of GMT?  then subtract offset
 805                         #
 806                         if ( $tz_mod == '+' ) {
 807                                 $offset_secs = $offset_secs * -1;
 808                         }
 809
 810                         $offset = $offset_secs;
 811                 }
 812                 $epoch = $epoch + $offset;
 813                 return $epoch;
 814         }
 815         else {
 816                 return -1;
 817         }
 818         }
 819 function wp_rss ($url, $num_items) {
 820         //ini_set("display_errors", false); uncomment to suppress php errors thrown if the feed is not returned.
 821         $rss = fetch_rss($url);
 822                 if ( $rss ) {
 823                         echo "<ul>";
 824                         $rss->items = array_slice($rss->items, 0, $num_items);
 825                                 foreach ($rss->items as $item ) {
 826                                         echo "<li>\n";
 827                                         echo "<a href='$item[link]' title='$item[description]'>";
 828                                         echo htmlentities($item['title']);
 829                                         echo "</a><br />\n";
 830                                         echo "</li>\n";
 831                                 }
 832                         echo "</ul>";
 833         }
 834                 else {
 835                         echo "an error has occured the feed is probably down, try again later.";
 836         }
 837 }
 838
 839 function get_rss ($url, $num_items = 5) { // Like get posts, but for RSS
 840         $rss = fetch_rss($url);
 841         if ( $rss ) {
 842                 $rss->items = array_slice($rss->items, 0, $num_items);
 843                 foreach ($rss->items as $item ) {
 844                         echo "<li>\n";
 845                         echo "<a href='$item[link]' title='$item[description]'>";
 846                         echo htmlentities($item['title']);
 847                         echo "</a><br />\n";
 848                         echo "</li>\n";
 849                 }
 850         } else {
 851                 return false;
 852         }
 853 }
 854 ?>