rss_parse.inc
1: <?php
2:
3: /**
4: * Project: MagpieRSS: a simple RSS integration tool
5: * File: rss_parse.inc - parse an RSS or Atom feed
6: * return as a simple object.
7: *
8: * Handles RSS 0.9x, RSS 2.0, RSS 1.0, and Atom 0.3
9: *
10: * The lastest version of MagpieRSS can be obtained from:
11: * http://magpierss.sourceforge.net
12: *
13: * For questions, help, comments, discussion, etc., please join the
14: * Magpie mailing list:
15: * magpierss-general@lists.sourceforge.net
16: *
17: * @author Kellan Elliott-McCrea <kellan@protest.net>
18: * @version 0.7a
19: * @license GPL
20: *
21: */
22:
23: define('RSS', 'RSS');
24: define('ATOM', 'Atom');
25:
26: require_once (MAGPIE_DIR . 'rss_utils.inc');
27:
28: /**
29: * Hybrid parser, and object, takes RSS as a string and returns a simple object.
30: *
31: * see: rss_fetch.inc for a simpler interface with integrated caching support
32: *
33: */
34: class MagpieRSS {
35: var $parser;
36:
37: var $current_item = array(); // item currently being parsed
38: var $items = array(); // collection of parsed items
39: var $channel = array(); // hash of channel fields
40: var $textinput = array();
41: var $image = array();
42: var $feed_type;
43: var $feed_version;
44: var $encoding = ''; // output encoding of parsed rss
45:
46: var $_source_encoding = ''; // only set if we have to parse xml prolog
47:
48: var $ERROR = "";
49: var $WARNING = "";
50:
51: // define some constants
52:
53: var $_CONTENT_CONSTRUCTS = array('content', 'summary', 'info', 'title', 'tagline', 'copyright');
54: var $_KNOWN_ENCODINGS = array('UTF-8', 'US-ASCII', 'ISO-8859-1');
55:
56: // parser variables, useless if you're not a parser, treat as private
57: var $stack = array(); // parser stack
58: var $inchannel = false;
59: var $initem = false;
60: var $incontent = false; // if in Atom <content mode="xml"> field
61: var $intextinput = false;
62: var $inimage = false;
63: var $current_namespace = false;
64:
65:
66: /**
67: * Set up XML parser, parse source, and return populated RSS object..
68: *
69: * @param string $source string containing the RSS to be parsed
70: *
71: * NOTE: Probably a good idea to leave the encoding options alone unless
72: * you know what you're doing as PHP's character set support is
73: * a little weird.
74: *
75: * NOTE: A lot of this is unnecessary but harmless with PHP5
76: *
77: *
78: * @param string $output_encoding output the parsed RSS in this character
79: * set defaults to ISO-8859-1 as this is PHP's
80: * default.
81: *
82: * NOTE: might be changed to UTF-8 in future
83: * versions.
84: *
85: * @param string $input_encoding the character set of the incoming RSS source.
86: * Leave blank and Magpie will try to figure it
87: * out.
88: *
89: *
90: * @param bool $detect_encoding if false Magpie won't attempt to detect
91: * source encoding. (caveat emptor)
92: *
93: */
94: function MagpieRSS ($source, $output_encoding='ISO-8859-1',
95: $input_encoding=null, $detect_encoding=true)
96: {
97: # if PHP xml isn't compiled in, die
98: #
99: if (!function_exists('xml_parser_create')) {
100: $this->error( "Failed to load PHP's XML Extension. " .
101: "http://www.php.net/manual/en/ref.xml.php",
102: E_USER_ERROR );
103: }
104:
105: list($parser, $source) = $this->create_parser($source,
106: $output_encoding, $input_encoding, $detect_encoding);
107:
108:
109: if (!is_resource($parser)) {
110: $this->error( "Failed to create an instance of PHP's XML parser. " .
111: "http://www.php.net/manual/en/ref.xml.php",
112: E_USER_ERROR );
113: }
114:
115:
116: $this->parser = $parser;
117:
118: # pass in parser, and a reference to this object
119: # setup handlers
120: #
121: xml_set_object( $this->parser, $this );
122: xml_set_element_handler($this->parser,
123: 'feed_start_element', 'feed_end_element' );
124:
125: xml_set_character_data_handler( $this->parser, 'feed_cdata' );
126:
127: $status = xml_parse( $this->parser, $source );
128:
129: if (! $status ) {
130: $errorcode = xml_get_error_code( $this->parser );
131: if ( $errorcode != XML_ERROR_NONE ) {
132: $xml_error = xml_error_string( $errorcode );
133: $error_line = xml_get_current_line_number($this->parser);
134: $error_col = xml_get_current_column_number($this->parser);
135: $errormsg = "$xml_error at line $error_line, column $error_col";
136:
137: $this->error( $errormsg );
138: }
139: }
140:
141: xml_parser_free( $this->parser );
142:
143: $this->normalize();
144: }
145:
146: function feed_start_element($p, $element, &$attrs) {
147: $el = $element = strtolower($element);
148: $attrs = array_change_key_case($attrs, CASE_LOWER);
149:
150: // check for a namespace, and split if found
151: $ns = false;
152: if ( strpos( $element, ':' ) ) {
153: list($ns, $el) = explode( ':', $element, 2);
154: }
155: if ( $ns and $ns != 'rdf' ) {
156: $this->current_namespace = $ns;
157: }
158:
159: # if feed type isn't set, then this is first element of feed
160: # identify feed from root element
161: #
162: if (!isset($this->feed_type) ) {
163: if ( $el == 'rdf' ) {
164: $this->feed_type = RSS;
165: $this->feed_version = '1.0';
166: }
167: elseif ( $el == 'rss' ) {
168: $this->feed_type = RSS;
169: $this->feed_version = $attrs['version'];
170: }
171: elseif ( $el == 'feed' ) {
172: $this->feed_type = ATOM;
173: $this->feed_version = $attrs['version'];
174: $this->inchannel = true;
175: }
176: return;
177: }
178:
179: if ( $el == 'channel' )
180: {
181: $this->inchannel = true;
182: }
183: elseif ($el == 'item' or $el == 'entry' )
184: {
185: $this->initem = true;
186: if ( isset($attrs['rdf:about']) ) {
187: $this->current_item['about'] = $attrs['rdf:about'];
188: }
189: }
190:
191: // if we're in the default namespace of an RSS feed,
192: // record textinput or image fields
193: elseif (
194: $this->feed_type == RSS and
195: $this->current_namespace == '' and
196: $el == 'textinput' )
197: {
198: $this->intextinput = true;
199: }
200:
201: elseif (
202: $this->feed_type == RSS and
203: $this->current_namespace == '' and
204: $el == 'image' )
205: {
206: $this->inimage = true;
207: }
208:
209: # handle atom content constructs
210: elseif ( $this->feed_type == ATOM and in_array($el, $this->_CONTENT_CONSTRUCTS) )
211: {
212: // avoid clashing w/ RSS mod_content
213: if ($el == 'content' ) {
214: $el = 'atom_content';
215: }
216:
217: $this->incontent = $el;
218:
219:
220: }
221:
222: // if inside an Atom content construct (e.g. content or summary) field treat tags as text
223: elseif ($this->feed_type == ATOM and $this->incontent )
224: {
225: // if tags are inlined, then flatten
226: $attrs_str = join(' ',
227: array_map('map_attrs',
228: array_keys($attrs),
229: array_values($attrs) ) );
230:
231: $this->append_content( "<$element $attrs_str>" );
232:
233: array_unshift( $this->stack, $el );
234: }
235:
236: // Atom support many links per containging element.
237: // Magpie treats link elements of type rel='alternate'
238: // as being equivalent to RSS's simple link element.
239: //
240: elseif ($this->feed_type == ATOM and $el == 'link' )
241: {
242: if ( isset($attrs['rel']) and $attrs['rel'] == 'alternate' )
243: {
244: $link_el = 'link';
245: }
246: else {
247: $link_el = 'link_' . $attrs['rel'];
248: }
249:
250: $this->append($link_el, $attrs['href']);
251: }
252: // set stack[0] to current element
253: else {
254: array_unshift($this->stack, $el);
255: }
256: }
257:
258:
259:
260: function feed_cdata ($p, $text) {
261: if ($this->feed_type == ATOM and $this->incontent)
262: {
263: $this->append_content( $text );
264: }
265: else {
266: $current_el = join('_', array_reverse($this->stack));
267: $this->append($current_el, $text);
268: }
269: }
270:
271: function feed_end_element ($p, $el) {
272: $el = strtolower($el);
273:
274: if ( $el == 'item' or $el == 'entry' )
275: {
276: $this->items[] = $this->current_item;
277: $this->current_item = array();
278: $this->initem = false;
279: }
280: elseif ($this->feed_type == RSS and $this->current_namespace == '' and $el == 'textinput' )
281: {
282: $this->intextinput = false;
283: }
284: elseif ($this->feed_type == RSS and $this->current_namespace == '' and $el == 'image' )
285: {
286: $this->inimage = false;
287: }
288: elseif ($this->feed_type == ATOM and in_array($el, $this->_CONTENT_CONSTRUCTS) )
289: {
290: $this->incontent = false;
291: }
292: elseif ($el == 'channel' or $el == 'feed' )
293: {
294: $this->inchannel = false;
295: }
296: elseif ($this->feed_type == ATOM and $this->incontent ) {
297: // balance tags properly
298: // note: i don't think this is actually neccessary
299: if ( $this->stack[0] == $el )
300: {
301: $this->append_content("</$el>");
302: }
303: else {
304: $this->append_content("<$el />");
305: }
306:
307: array_shift( $this->stack );
308: }
309: else {
310: array_shift( $this->stack );
311: }
312:
313: $this->current_namespace = false;
314: }
315:
316: function concat (&$str1, $str2="") {
317: if (!isset($str1) ) {
318: $str1="";
319: }
320: $str1 .= $str2;
321: }
322:
323:
324:
325: function append_content($text) {
326: if ( $this->initem ) {
327: $this->concat( $this->current_item[ $this->incontent ], $text );
328: }
329: elseif ( $this->inchannel ) {
330: $this->concat( $this->channel[ $this->incontent ], $text );
331: }
332: }
333:
334: // smart append - field and namespace aware
335: function append($el, $text) {
336: if (!$el) {
337: return;
338: }
339: if ( $this->current_namespace )
340: {
341: if ( $this->initem ) {
342: $this->concat(
343: $this->current_item[ $this->current_namespace ][ $el ], $text);
344: }
345: elseif ($this->inchannel) {
346: $this->concat(
347: $this->channel[ $this->current_namespace][ $el ], $text );
348: }
349: elseif ($this->intextinput) {
350: $this->concat(
351: $this->textinput[ $this->current_namespace][ $el ], $text );
352: }
353: elseif ($this->inimage) {
354: $this->concat(
355: $this->image[ $this->current_namespace ][ $el ], $text );
356: }
357: }
358: else {
359: if ( $this->initem ) {
360: $this->concat(
361: $this->current_item[ $el ], $text);
362: }
363: elseif ($this->intextinput) {
364: $this->concat(
365: $this->textinput[ $el ], $text );
366: }
367: elseif ($this->inimage) {
368: $this->concat(
369: $this->image[ $el ], $text );
370: }
371: elseif ($this->inchannel) {
372: $this->concat(
373: $this->channel[ $el ], $text );
374: }
375:
376: }
377: }
378:
379: function normalize () {
380: // if atom populate rss fields
381: if ( $this->is_atom() ) {
382: $this->channel['description'] = $this->channel['tagline'];
383: for ( $i = 0; $i < count($this->items); $i++) {
384: $item = $this->items[$i];
385: if ( isset($item['summary']) )
386: $item['description'] = $item['summary'];
387: if ( isset($item['atom_content']))
388: $item['content']['encoded'] = $item['atom_content'];
389:
390: $atom_date = (isset($item['issued']) ) ? $item['issued'] : $item['modified'];
391: if ( $atom_date ) {
392: $epoch = @parse_w3cdtf($atom_date);
393: if ($epoch and $epoch > 0) {
394: $item['date_timestamp'] = $epoch;
395: }
396: }
397:
398: $this->items[$i] = $item;
399: }
400: }
401: elseif ( $this->is_rss() ) {
402: $this->channel['tagline'] = $this->channel['description'];
403: for ( $i = 0; $i < count($this->items); $i++) {
404: $item = $this->items[$i];
405: if ( isset($item['description']))
406: $item['summary'] = $item['description'];
407: if ( isset($item['content']['encoded'] ) )
408: $item['atom_content'] = $item['content']['encoded'];
409:
410: if ( $this->is_rss() == '1.0' and isset($item['dc']['date']) ) {
411: $epoch = @parse_w3cdtf($item['dc']['date']);
412: if ($epoch and $epoch > 0) {
413: $item['date_timestamp'] = $epoch;
414: }
415: }
416: elseif ( isset($item['pubdate']) ) {
417: $epoch = @strtotime($item['pubdate']);
418: if ($epoch > 0) {
419: $item['date_timestamp'] = $epoch;
420: }
421: }
422:
423: $this->items[$i] = $item;
424: }
425: }
426: }
427:
428:
429: function is_rss () {
430: if ( $this->feed_type == RSS ) {
431: return $this->feed_version;
432: }
433: else {
434: return false;
435: }
436: }
437:
438: function is_atom() {
439: if ( $this->feed_type == ATOM ) {
440: return $this->feed_version;
441: }
442: else {
443: return false;
444: }
445: }
446:
447: /**
448: * return XML parser, and possibly re-encoded source
449: *
450: */
451: function create_parser($source, $out_enc, $in_enc, $detect) {
452: if ( substr(phpversion(),0,1) == 5) {
453: $parser = $this->php5_create_parser($in_enc, $detect);
454: }
455: else {
456: list($parser, $source) = $this->php4_create_parser($source, $in_enc, $detect);
457: }
458: if ($out_enc) {
459: $this->encoding = $out_enc;
460: xml_parser_set_option($parser, XML_OPTION_TARGET_ENCODING, $out_enc);
461: }
462:
463: return array($parser, $source);
464: }
465:
466: /**
467: * Instantiate an XML parser under PHP5
468: *
469: * PHP5 will do a fine job of detecting input encoding
470: * if passed an empty string as the encoding.
471: *
472: * All hail libxml2!
473: *
474: */
475: function php5_create_parser($in_enc, $detect) {
476: // by default php5 does a fine job of detecting input encodings
477: if(!$detect && $in_enc) {
478: return xml_parser_create($in_enc);
479: }
480: else {
481: return xml_parser_create('');
482: }
483: }
484:
485: /**
486: * Instaniate an XML parser under PHP4
487: *
488: * Unfortunately PHP4's support for character encodings
489: * and especially XML and character encodings sucks. As
490: * long as the documents you parse only contain characters
491: * from the ISO-8859-1 character set (a superset of ASCII,
492: * and a subset of UTF-8) you're fine. However once you
493: * step out of that comfy little world things get mad, bad,
494: * and dangerous to know.
495: *
496: * The following code is based on SJM's work with FoF
497: * @see http://minutillo.com/steve/weblog/2004/6/17/php-xml-and-character-encodings-a-tale-of-sadness-rage-and-data-loss
498: *
499: */
500: function php4_create_parser($source, $in_enc, $detect) {
501: if ( !$detect ) {
502: return array(xml_parser_create($in_enc), $source);
503: }
504:
505: if (!$in_enc) {
506: if (preg_match('/<?xml.*encoding=[\'"](.*?)[\'"].*?>/m', $source, $m)) {
507: $in_enc = strtoupper($m[1]);
508: $this->source_encoding = $in_enc;
509: }
510: else {
511: $in_enc = 'UTF-8';
512: }
513: }
514:
515: if ($this->known_encoding($in_enc)) {
516: return array(xml_parser_create($in_enc), $source);
517: }
518:
519: // the dectected encoding is not one of the simple encodings PHP knows
520:
521: // attempt to use the iconv extension to
522: // cast the XML to a known encoding
523: // @see http://php.net/iconv
524:
525: if (function_exists('iconv')) {
526: $encoded_source = iconv($in_enc,'UTF-8', $source);
527: if ($encoded_source) {
528: return array(xml_parser_create('UTF-8'), $encoded_source);
529: }
530: }
531:
532: // iconv didn't work, try mb_convert_encoding
533: // @see http://php.net/mbstring
534: if(function_exists('mb_convert_encoding')) {
535: $encoded_source = mb_convert_encoding($source, 'UTF-8', $in_enc );
536: if ($encoded_source) {
537: return array(xml_parser_create('UTF-8'), $encoded_source);
538: }
539: }
540:
541: // else
542: $this->error("Feed is in an unsupported character encoding. ($in_enc) " .
543: "You may see strange artifacts, and mangled characters.",
544: E_USER_NOTICE);
545:
546: return array(xml_parser_create(), $source);
547: }
548:
549: function known_encoding($enc) {
550: $enc = strtoupper($enc);
551: if ( in_array($enc, $this->_KNOWN_ENCODINGS) ) {
552: return $enc;
553: }
554: else {
555: return false;
556: }
557: }
558:
559: function error ($errormsg, $lvl=E_USER_WARNING) {
560: // append PHP's error message if track_errors enabled
561: if ( isset($php_errormsg) ) {
562: $errormsg .= " ($php_errormsg)";
563: }
564: // if ( MAGPIE_DEBUG ) {
565: // trigger_error($errormsg, $lvl);
566: // }
567: // else {
568: error_log( $errormsg, 0);
569: // }
570:
571: $notices = E_USER_NOTICE|E_NOTICE;
572: if ( $lvl & $notices ) {
573: $this->WARNING = $errormsg;
574: } else {
575: $this->ERROR = $errormsg;
576: }
577: }
578:
579:
580: } // end class RSS
581:
582: function map_attrs($k, $v) {
583: return "$k=\"$v\"";
584: }
585:
586: // patch to support medieval versions of PHP4.1.x,
587: // courtesy, Ryan Currie, ryan@digibliss.com
588:
589: if (!function_exists('array_change_key_case')) {
590: define("CASE_UPPER",1);
591: define("CASE_LOWER",0);
592:
593:
594: function array_change_key_case($array,$case=CASE_LOWER) {
595: if ($case=CASE_LOWER) $cmd=strtolower;
596: elseif ($case=CASE_UPPER) $cmd=strtoupper;
597: foreach($array as $key=>$value) {
598: $output[$cmd($key)]=$value;
599: }
600: return $output;
601: }
602:
603: }
604:
605: ?>