activitypub / includes / functions.php

functions.php in ActivityPub 2.1.0, at includes/functions.php

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1	<?php
2	namespace Activitypub;
3
4	use WP_Error;
5	use Activitypub\Http;
6	use Activitypub\Comment;
7	use Activitypub\Webfinger;
8	use Activitypub\Activity\Activity;
9	use Activitypub\Collection\Followers;
10	use Activitypub\Collection\Users;
11
12	/**
13	* Returns the ActivityPub default JSON-context
14	*
15	* @return array the activitypub context
16	*/
17	function get_context() {
18	$context = Activity::JSON_LD_CONTEXT;
19
20	return \apply_filters( 'activitypub_json_context', $context );
21	}
22
23	function safe_remote_post( $url, $body, $user_id ) {
24	return Http::post( $url, $body, $user_id );
25	}
26
27	function safe_remote_get( $url ) {
28	return Http::get( $url );
29	}
30
31	/**
32	* Returns a users WebFinger "resource"
33	*
34	* @param int $user_id The User-ID.
35	*
36	* @return string The User-Resource.
37	*/
38	function get_webfinger_resource( $user_id ) {
39	return Webfinger::get_user_resource( $user_id );
40	}
41
42	/**
43	* Requests the Meta-Data from the Actors profile
44	*
45	* @param string $actor The Actor URL.
46	* @param bool $cached If the result should be cached.
47	*
48	* @return array\|WP_Error The Actor profile as array or WP_Error on failure.
49	*/
50	function get_remote_metadata_by_actor( $actor, $cached = true ) {
51	$pre = apply_filters( 'pre_get_remote_metadata_by_actor', false, $actor );
52	if ( $pre ) {
53	return $pre;
54	}
55	if ( preg_match( '/^@?' . ACTIVITYPUB_USERNAME_REGEXP . '$/i', $actor ) ) {
56	$actor = Webfinger::resolve( $actor );
57	}
58
59	if ( ! $actor ) {
60	return new WP_Error( 'activitypub_no_valid_actor_identifier', \__( 'The "actor" identifier is not valid', 'activitypub' ), array( 'status' => 404, 'actor' => $actor ) );
61	}
62
63	if ( is_wp_error( $actor ) ) {
64	return $actor;
65	}
66
67	$transient_key = 'activitypub_' . $actor;
68
69	// only check the cache if needed.
70	if ( $cached ) {
71	$metadata = \get_transient( $transient_key );
72
73	if ( $metadata ) {
74	return $metadata;
75	}
76	}
77
78	if ( ! \wp_http_validate_url( $actor ) ) {
79	$metadata = new WP_Error( 'activitypub_no_valid_actor_url', \__( 'The "actor" is no valid URL', 'activitypub' ), array( 'status' => 400, 'actor' => $actor ) );
80	return $metadata;
81	}
82
83	$response = Http::get( $actor );
84
85	if ( \is_wp_error( $response ) ) {
86	return $response;
87	}
88
89	$metadata = \wp_remote_retrieve_body( $response );
90	$metadata = \json_decode( $metadata, true );
91
92	if ( ! $metadata ) {
93	$metadata = new WP_Error( 'activitypub_invalid_json', \__( 'No valid JSON data', 'activitypub' ), array( 'status' => 400, 'actor' => $actor ) );
94	return $metadata;
95	}
96
97	\set_transient( $transient_key, $metadata, WEEK_IN_SECONDS );
98
99	return $metadata;
100	}
101
102	/**
103	* Returns the followers of a given user.
104	*
105	* @param int $user_id The User-ID.
106	*
107	* @return array The followers.
108	*/
109	function get_followers( $user_id ) {
110	return Followers::get_followers( $user_id );
111	}
112
113	/**
114	* Count the number of followers for a given user.
115	*
116	* @param int $user_id The User-ID.
117	*
118	* @return int The number of followers.
119	*/
120	function count_followers( $user_id ) {
121	return Followers::count_followers( $user_id );
122	}
123
124	/**
125	* Examine a url and try to determine the author ID it represents.
126	*
127	* Checks are supposedly from the hosted site blog.
128	*
129	* @param string $url Permalink to check.
130	*
131	* @return int User ID, or 0 on failure.
132	*/
133	function url_to_authorid( $url ) {
134	global $wp_rewrite;
135
136	// check if url hase the same host
137	if ( \wp_parse_url( \site_url(), \PHP_URL_HOST ) !== \wp_parse_url( $url, \PHP_URL_HOST ) ) {
138	return 0;
139	}
140
141	// first, check to see if there is a 'author=N' to match against
142	if ( \preg_match( '/[?&]author=(\d+)/i', $url, $values ) ) {
143	$id = \absint( $values[1] );
144	if ( $id ) {
145	return $id;
146	}
147	}
148
149	// check to see if we are using rewrite rules
150	$rewrite = $wp_rewrite->wp_rewrite_rules();
151
152	// not using rewrite rules, and 'author=N' method failed, so we're out of options
153	if ( empty( $rewrite ) ) {
154	return 0;
155	}
156
157	// generate rewrite rule for the author url
158	$author_rewrite = $wp_rewrite->get_author_permastruct();
159	$author_regexp = \str_replace( '%author%', '', $author_rewrite );
160
161	// match the rewrite rule with the passed url
162	if ( \preg_match( '/https?:\/\/(.+)' . \preg_quote( $author_regexp, '/' ) . '([^\/]+)/i', $url, $match ) ) {
163	$user = \get_user_by( 'slug', $match[2] );
164	if ( $user ) {
165	return $user->ID;
166	}
167	}
168
169	return 0;
170	}
171
172	/**
173	* Verify if url is a wp_ap_comment,
174	* Or if it is a previously received remote comment
175	*
176	* @return int comment_id
177	*/
178	function is_comment() {
179	$comment_id = get_query_var( 'c', null );
180
181	if ( ! is_null( $comment_id ) ) {
182	$comment = \get_comment( $comment_id );
183
184	// Only return local origin comments
185	if ( $comment && $comment->user_id ) {
186	return $comment_id;
187	}
188	}
189
190	return false;
191	}
192
193	/**
194	* Check for Tombstone Objects
195	*
196	* @see https://www.w3.org/TR/activitypub/#delete-activity-outbox
197	*
198	* @param WP_Error $wp_error A WP_Error-Response of an HTTP-Request
199	*
200	* @return boolean true if HTTP-Code is 410 or 404
201	*/
202	function is_tombstone( $wp_error ) {
203	if ( ! is_wp_error( $wp_error ) ) {
204	return false;
205	}
206
207	if ( in_array( (int) $wp_error->get_error_code(), array( 404, 410 ), true ) ) {
208	return true;
209	}
210
211	return false;
212	}
213
214	/**
215	* Get the REST URL relative to this plugin's namespace.
216	*
217	* @param string $path Optional. REST route path. Otherwise this plugin's namespaced root.
218	*
219	* @return string REST URL relative to this plugin's namespace.
220	*/
221	function get_rest_url_by_path( $path = '' ) {
222	// we'll handle the leading slash.
223	$path = ltrim( $path, '/' );
224	$namespaced_path = sprintf( '/%s/%s', ACTIVITYPUB_REST_NAMESPACE, $path );
225	return \get_rest_url( null, $namespaced_path );
226	}
227
228	/**
229	* Convert a string from camelCase to snake_case.
230	*
231	* @param string $string The string to convert.
232	*
233	* @return string The converted string.
234	*/
235	// phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound
236	function camel_to_snake_case( $string ) {
237	return strtolower( preg_replace( '/(?<!^)[A-Z]/', '_$0', $string ) );
238	}
239
240	/**
241	* Convert a string from snake_case to camelCase.
242	*
243	* @param string $string The string to convert.
244	*
245	* @return string The converted string.
246	*/
247	// phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound
248	function snake_to_camel_case( $string ) {
249	return lcfirst( str_replace( '_', '', ucwords( $string, '_' ) ) );
250	}
251
252	/**
253	* Escapes a Tag, to be used as a hashtag.
254	*
255	* @param string $string The string to escape.
256	*
257	* @return string The escaped hastag.
258	*/
259	function esc_hashtag( $string ) {
260
261	$hashtag = \wp_specialchars_decode( $string, ENT_QUOTES );
262	// Remove all characters that are not letters, numbers, or underscores.
263	$hashtag = \preg_replace( '/emoji-regex(*SKIP)(?!)\|[^\p{L}\p{Nd}_]+/u', '_', $hashtag );
264
265	// Capitalize every letter that is preceded by an underscore.
266	$hashtag = preg_replace_callback(
267	'/_(.)/',
268	function ( $matches ) {
269	return '' . strtoupper( $matches[1] );
270	},
271	$hashtag
272	);
273
274	// Add a hashtag to the beginning of the string.
275	$hashtag = ltrim( $hashtag, '#' );
276	$hashtag = '#' . $hashtag;
277
278	/**
279	* Allow defining your own custom hashtag generation rules.
280	*
281	* @param string $hashtag The hashtag to be returned.
282	* @param string $string The original string.
283	*/
284	$hashtag = apply_filters( 'activitypub_esc_hashtag', $hashtag, $string );
285
286	return esc_html( $hashtag );
287	}
288
289	/**
290	* Check if a request is for an ActivityPub request.
291	*
292	* @return bool False by default.
293	*/
294	function is_activitypub_request() {
295	global $wp_query;
296
297	/*
298	* ActivityPub requests are currently only made for
299	* author archives, singular posts, and the homepage.
300	*/
301	if ( ! \is_author() && ! \is_singular() && ! \is_home() && ! defined( '\REST_REQUEST' ) ) {
302	return false;
303	}
304
305	// Check if the current post type supports ActivityPub.
306	if ( \is_singular() ) {
307	$queried_object = \get_queried_object();
308	$post_type = \get_post_type( $queried_object );
309
310	if ( ! \post_type_supports( $post_type, 'activitypub' ) ) {
311	return false;
312	}
313	}
314
315	// Check if header already sent.
316	if ( ! \headers_sent() && ACTIVITYPUB_SEND_VARY_HEADER ) {
317	// Send Vary header for Accept header.
318	\header( 'Vary: Accept' );
319	}
320
321	// One can trigger an ActivityPub request by adding ?activitypub to the URL.
322	// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.VariableRedeclaration
323	global $wp_query;
324	if ( isset( $wp_query->query_vars['activitypub'] ) ) {
325	return true;
326	}
327
328	/*
329	* The other (more common) option to make an ActivityPub request
330	* is to send an Accept header.
331	*/
332	if ( isset( $_SERVER['HTTP_ACCEPT'] ) ) {
333	$accept = sanitize_text_field( wp_unslash( $_SERVER['HTTP_ACCEPT'] ) );
334
335	/*
336	* $accept can be a single value, or a comma separated list of values.
337	* We want to support both scenarios,
338	* and return true when the header includes at least one of the following:
339	* - application/activity+json
340	* - application/ld+json
341	* - application/json
342	*/
343	if ( preg_match( '/(application\/(ld\+json\|activity\+json\|json))/i', $accept ) ) {
344	return true;
345	}
346	}
347
348	return false;
349	}
350
351	/**
352	* This function checks if a user is disabled for ActivityPub.
353	*
354	* @param int $user_id The User-ID.
355	*
356	* @return boolean True if the user is disabled, false otherwise.
357	*/
358	function is_user_disabled( $user_id ) {
359	$return = false;
360
361	switch ( $user_id ) {
362	// if the user is the application user, it's always enabled.
363	case \Activitypub\Collection\Users::APPLICATION_USER_ID:
364	$return = false;
365	break;
366	// if the user is the blog user, it's only enabled in single-user mode.
367	case \Activitypub\Collection\Users::BLOG_USER_ID:
368	if ( is_user_type_disabled( 'blog' ) ) {
369	$return = true;
370	break;
371	}
372
373	$return = false;
374	break;
375	// if the user is any other user, it's enabled if it can publish posts.
376	default:
377	if ( ! \get_user_by( 'id', $user_id ) ) {
378	$return = true;
379	break;
380	}
381
382	if ( is_user_type_disabled( 'user' ) ) {
383	$return = true;
384	break;
385	}
386
387	if ( ! \user_can( $user_id, 'publish_posts' ) ) {
388	$return = true;
389	break;
390	}
391
392	$return = false;
393	break;
394	}
395
396	return apply_filters( 'activitypub_is_user_disabled', $return, $user_id );
397	}
398
399	/**
400	* Checks if a User-Type is disabled for ActivityPub.
401	*
402	* This function is used to check if the 'blog' or 'user'
403	* type is disabled for ActivityPub.
404	*
405	* @param enum $type Can be 'blog' or 'user'.
406	*
407	* @return boolean True if the user type is disabled, false otherwise.
408	*/
409	function is_user_type_disabled( $type ) {
410	switch ( $type ) {
411	case 'blog':
412	if ( \defined( 'ACTIVITYPUB_SINGLE_USER_MODE' ) ) {
413	if ( ACTIVITYPUB_SINGLE_USER_MODE ) {
414	$return = false;
415	break;
416	}
417	}
418
419	if ( \defined( 'ACTIVITYPUB_DISABLE_BLOG_USER' ) ) {
420	$return = ACTIVITYPUB_DISABLE_BLOG_USER;
421	break;
422	}
423
424	if ( '1' !== \get_option( 'activitypub_enable_blog_user', '0' ) ) {
425	$return = true;
426	break;
427	}
428
429	$return = false;
430	break;
431	case 'user':
432	if ( \defined( 'ACTIVITYPUB_SINGLE_USER_MODE' ) ) {
433	if ( ACTIVITYPUB_SINGLE_USER_MODE ) {
434	$return = true;
435	break;
436	}
437	}
438
439	if ( \defined( 'ACTIVITYPUB_DISABLE_USER' ) ) {
440	$return = ACTIVITYPUB_DISABLE_USER;
441	break;
442	}
443
444	if ( '1' !== \get_option( 'activitypub_enable_users', '1' ) ) {
445	$return = true;
446	break;
447	}
448
449	$return = false;
450	break;
451	default:
452	$return = new WP_Error( 'activitypub_wrong_user_type', __( 'Wrong user type', 'activitypub' ), array( 'status' => 400 ) );
453	break;
454	}
455
456	return apply_filters( 'activitypub_is_user_type_disabled', $return, $type );
457	}
458
459	/**
460	* Check if the blog is in single-user mode.
461	*
462	* @return boolean True if the blog is in single-user mode, false otherwise.
463	*/
464	function is_single_user() {
465	if (
466	false === is_user_type_disabled( 'blog' ) &&
467	true === is_user_type_disabled( 'user' )
468	) {
469	return true;
470	}
471
472	return false;
473	}
474
475	/**
476	* Check if a site supports the block editor.
477	*
478	* @return boolean True if the site supports the block editor, false otherwise.
479	*/
480	function site_supports_blocks() {
481	if ( \version_compare( \get_bloginfo( 'version' ), '5.9', '<' ) ) {
482	return false;
483	}
484
485	if ( ! \function_exists( 'register_block_type_from_metadata' ) ) {
486	return false;
487	}
488
489	/**
490	* Allow plugins to disable block editor support,
491	* thus disabling blocks registered by the ActivityPub plugin.
492	*
493	* @param boolean $supports_blocks True if the site supports the block editor, false otherwise.
494	*/
495	return apply_filters( 'activitypub_site_supports_blocks', true );
496	}
497
498	/**
499	* Check if data is valid JSON.
500	*
501	* @param string $data The data to check.
502	*
503	* @return boolean True if the data is JSON, false otherwise.
504	*/
505	function is_json( $data ) {
506	return \is_array( \json_decode( $data, true ) ) ? true : false;
507	}
508
509	/**
510	* Check if a blog is public based on the `blog_public` option
511	*
512	* @return bollean True if public, false if not
513	*/
514	function is_blog_public() {
515	return (bool) apply_filters( 'activitypub_is_blog_public', \get_option( 'blog_public', 1 ) );
516	}
517
518	/**
519	* Sanitize a URL
520	*
521	* @param string $value The URL to sanitize
522	*
523	* @return string\|null The sanitized URL or null if invalid
524	*/
525	function sanitize_url( $value ) {
526	if ( filter_var( $value, FILTER_VALIDATE_URL ) === false ) {
527	return null;
528	}
529
530	return esc_url_raw( $value );
531	}
532
533	/**
534	* Extract recipient URLs from Activity object
535	*
536	* @param array $data
537	*
538	* @return array The list of user URLs
539	*/
540	function extract_recipients_from_activity( $data ) {
541	$recipient_items = array();
542
543	foreach ( array( 'to', 'bto', 'cc', 'bcc', 'audience' ) as $i ) {
544	if ( array_key_exists( $i, $data ) ) {
545	if ( is_array( $data[ $i ] ) ) {
546	$recipient = $data[ $i ];
547	} else {
548	$recipient = array( $data[ $i ] );
549	}
550	$recipient_items = array_merge( $recipient_items, $recipient );
551	}
552
553	if ( is_array( $data['object'] ) && array_key_exists( $i, $data['object'] ) ) {
554	if ( is_array( $data['object'][ $i ] ) ) {
555	$recipient = $data['object'][ $i ];
556	} else {
557	$recipient = array( $data['object'][ $i ] );
558	}
559	$recipient_items = array_merge( $recipient_items, $recipient );
560	}
561	}
562
563	$recipients = array();
564
565	// flatten array
566	foreach ( $recipient_items as $recipient ) {
567	if ( is_array( $recipient ) ) {
568	// check if recipient is an object
569	if ( array_key_exists( 'id', $recipient ) ) {
570	$recipients[] = $recipient['id'];
571	}
572	} else {
573	$recipients[] = $recipient;
574	}
575	}
576
577	return array_unique( $recipients );
578	}
579
580	/**
581	* Check if passed Activity is Public
582	*
583	* @param array $data The Activity object as array
584	*
585	* @return boolean True if public, false if not
586	*/
587	function is_activity_public( $data ) {
588	$recipients = extract_recipients_from_activity( $data );
589
590	return in_array( 'https://www.w3.org/ns/activitystreams#Public', $recipients, true );
591	}
592
593	/**
594	* Get active users based on a given duration
595	*
596	* @param int $duration The duration to check in month(s)
597	*
598	* @return int The number of active users
599	*/
600	function get_active_users( $duration = 1 ) {
601
602	$duration = intval( $duration );
603	$transient_key = sprintf( 'monthly_active_users_%d', $duration );
604	$count = get_transient( $transient_key );
605
606	if ( false === $count ) {
607	global $wpdb;
608	$query = "SELECT COUNT( DISTINCT post_author ) FROM {$wpdb->posts} WHERE post_type = 'post' AND post_status = 'publish' AND post_date <= DATE_SUB( NOW(), INTERVAL %d MONTH )";
609	$query = $wpdb->prepare( $query, $duration );
610	$count = $wpdb->get_var( $query ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
611
612	set_transient( $transient_key, $count, DAY_IN_SECONDS );
613	}
614
615	// if 0 authors where active
616	if ( 0 === $count ) {
617	return 0;
618	}
619
620	// if single user mode
621	if ( is_single_user() ) {
622	return 1;
623	}
624
625	// if blog user is disabled
626	if ( is_user_disabled( Users::BLOG_USER_ID ) ) {
627	return $count;
628	}
629
630	// also count blog user
631	return $count + 1;
632	}
633
634	/**
635	* Get the total number of users
636	*
637	* @return int The total number of users
638	*/
639	function get_total_users() {
640	// if single user mode
641	if ( is_single_user() ) {
642	return 1;
643	}
644
645	$users = \get_users(
646	array(
647	'capability__in' => array( 'publish_posts' ),
648	)
649	);
650
651	if ( is_array( $users ) ) {
652	$users = count( $users );
653	} else {
654	$users = 1;
655	}
656
657	// if blog user is disabled
658	if ( is_user_disabled( Users::BLOG_USER_ID ) ) {
659	return $users;
660	}
661
662	return $users + 1;
663	}
664
665	/**
666	* Examine a comment ID and look up an existing comment it represents.
667	*
668	* @param string $id ActivityPub object ID (usually a URL) to check.
669	*
670	* @return int\|boolean Comment ID, or false on failure.
671	*/
672	function object_id_to_comment( $id ) {
673	return Comment::object_id_to_comment( $id );
674	}
675
676	/**
677	* Verify if URL is a local comment,
678	* Or if it is a previously received remote comment
679	* (For threading comments locally)
680	*
681	* @param string $url The URL to check.
682	*
683	* @return int comment_ID or null if not found
684	*/
685	function url_to_commentid( $url ) {
686	return Comment::url_to_commentid( $url );
687	}
688
689	/**
690	* Get the URI of an ActivityPub object
691	*
692	* @param array $object The ActivityPub object
693	*
694	* @return string The URI of the ActivityPub object
695	*/
696	function object_to_uri( $object ) {
697	// check if it is already simple
698	if ( ! $object \|\| is_string( $object ) ) {
699	return $object;
700	}
701
702	// check if it is a list, then take first item
703	// this plugin does not support collections
704	if ( array_is_list( $object ) ) {
705	$object = $object[0];
706	}
707
708	// check if it is simplified now
709	if ( is_string( $object ) ) {
710	return $object;
711	}
712
713	// return part of Object that makes most sense
714	switch ( $object['type'] ) {
715	case 'Link':
716	$object = $object['href'];
717	break;
718	default:
719	$object = $object['id'];
720	break;
721	}
722
723	return $object;
724	}
725
726	/**
727	* Check if a comment should be federated.
728	*
729	* We consider a comment should be federated if it is authored by a user that is
730	* not disabled for federation and if it is a reply directly to the post or to a
731	* federated comment.
732	*
733	* @param mixed $comment Comment object or ID.
734	*
735	* @return boolean True if the comment should be federated, false otherwise.
736	*/
737	function should_comment_be_federated( $comment ) {
738	return Comment::should_be_federated( $comment );
739	}
740
741	/**
742	* Check if a comment was federated.
743	*
744	* This function checks if a comment was federated via ActivityPub.
745	*
746	* @param mixed $comment Comment object or ID.
747	*
748	* @return boolean True if the comment was federated, false otherwise.
749	*/
750	function was_comment_sent( $comment ) {
751	return Comment::was_sent( $comment );
752	}
753
754	/**
755	* Check if a comment is federated.
756	*
757	* We consider a comment federated if comment was received via ActivityPub.
758	*
759	* Use this function to check if it is comment that was received via ActivityPub.
760	*
761	* @param mixed $comment Comment object or ID.
762	*
763	* @return boolean True if the comment is federated, false otherwise.
764	*/
765	function was_comment_received( $comment ) {
766	return Comment::was_received( $comment );
767	}
768
769	/**
770	* Check if a comment is local only.
771	*
772	* This function checks if a comment is local only and was not sent or received via ActivityPub.
773	*
774	* @param mixed $comment Comment object or ID.
775	*
776	* @return boolean True if the comment is local only, false otherwise.
777	*/
778	function is_local_comment( $comment ) {
779	return Comment::is_local( $comment );
780	}
781
782	/**
783	* Mark a WordPress object as federated.
784	*
785	* @param WP_Comment\|WP_Post\|mixed $wp_object
786	* @return void
787	*/
788	function set_wp_object_state( $wp_object, $state ) {
789	$meta_key = 'activitypub_status';
790
791	if ( $wp_object instanceof \WP_Post ) {
792	\update_post_meta( $wp_object->ID, $meta_key, $state );
793	} elseif ( $wp_object instanceof \WP_Comment ) {
794	\update_comment_meta( $wp_object->comment_ID, $meta_key, $state );
795	} else {
796	\apply_filters( 'activitypub_mark_wp_object_as_federated', $wp_object );
797	}
798	}
799
800	/**
801	* Get the description of a post type.
802	*
803	* Set some default descriptions for the default post types.
804	*
805	* @param WP_Post_Type $post_type The post type object.
806	*
807	* @return string The description of the post type.
808	*/
809	function get_post_type_description( $post_type ) {
810	$description = '';
811
812	switch ( $post_type->name ) {
813	case 'post':
814	$description = '';
815	break;
816	case 'page':
817	$description = '';
818	break;
819	case 'attachment':
820	$description = ' - ' . __( 'The attachments that you have uploaded to a post (images, videos, documents or other files).', 'activitypub' );
821	break;
822	default:
823	if ( ! empty( $post_type->description ) ) {
824	$description = ' - ' . $post_type->description;
825	}
826	}
827
828	return apply_filters( 'activitypub_post_type_description', $description, $post_type->name, $post_type );
829	}
830