activitypub / includes / functions.php

functions.php in ActivityPub 1.0.9, 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\Activity\Activity;
7	use Activitypub\Collection\Followers;
8
9	/**
10	* Returns the ActivityPub default JSON-context
11	*
12	* @return array the activitypub context
13	*/
14	function get_context() {
15	$context = Activity::CONTEXT;
16
17	return \apply_filters( 'activitypub_json_context', $context );
18	}
19
20	function safe_remote_post( $url, $body, $user_id ) {
21	return Http::post( $url, $body, $user_id );
22	}
23
24	function safe_remote_get( $url ) {
25	return Http::get( $url );
26	}
27
28	/**
29	* Returns a users WebFinger "resource"
30	*
31	* @param int $user_id The User-ID.
32	*
33	* @return string The User-Resource.
34	*/
35	function get_webfinger_resource( $user_id ) {
36	return Webfinger::get_user_resource( $user_id );
37	}
38
39	/**
40	* Requests the Meta-Data from the Actors profile
41	*
42	* @param string $actor The Actor URL.
43	* @param bool $cached If the result should be cached.
44	*
45	* @return array The Actor profile as array
46	*/
47	function get_remote_metadata_by_actor( $actor, $cached = true ) {
48	$pre = apply_filters( 'pre_get_remote_metadata_by_actor', false, $actor );
49	if ( $pre ) {
50	return $pre;
51	}
52	if ( preg_match( '/^@?' . ACTIVITYPUB_USERNAME_REGEXP . '$/i', $actor ) ) {
53	$actor = Webfinger::resolve( $actor );
54	}
55
56	if ( ! $actor ) {
57	return new WP_Error( 'activitypub_no_valid_actor_identifier', \__( 'The "actor" identifier is not valid', 'activitypub' ), array( 'status' => 404, 'actor' => $actor ) );
58	}
59
60	if ( is_wp_error( $actor ) ) {
61	return $actor;
62	}
63
64	$transient_key = 'activitypub_' . $actor;
65
66	// only check the cache if needed.
67	if ( $cached ) {
68	$metadata = \get_transient( $transient_key );
69
70	if ( $metadata ) {
71	return $metadata;
72	}
73	}
74
75	if ( ! \wp_http_validate_url( $actor ) ) {
76	$metadata = new WP_Error( 'activitypub_no_valid_actor_url', \__( 'The "actor" is no valid URL', 'activitypub' ), array( 'status' => 400, 'actor' => $actor ) );
77	return $metadata;
78	}
79
80	$response = Http::get( $actor );
81
82	if ( \is_wp_error( $response ) ) {
83	return $response;
84	}
85
86	$metadata = \wp_remote_retrieve_body( $response );
87	$metadata = \json_decode( $metadata, true );
88
89	if ( ! $metadata ) {
90	$metadata = new WP_Error( 'activitypub_invalid_json', \__( 'No valid JSON data', 'activitypub' ), array( 'status' => 400, 'actor' => $actor ) );
91	return $metadata;
92	}
93
94	\set_transient( $transient_key, $metadata, WEEK_IN_SECONDS );
95
96	return $metadata;
97	}
98
99	/**
100	* Returns the followers of a given user.
101	*
102	* @param int $user_id The User-ID.
103	*
104	* @return array The followers.
105	*/
106	function get_followers( $user_id ) {
107	return Followers::get_followers( $user_id );
108	}
109
110	/**
111	* Count the number of followers for a given user.
112	*
113	* @param int $user_id The User-ID.
114	*
115	* @return int The number of followers.
116	*/
117	function count_followers( $user_id ) {
118	return Followers::count_followers( $user_id );
119	}
120
121	/**
122	* Examine a url and try to determine the author ID it represents.
123	*
124	* Checks are supposedly from the hosted site blog.
125	*
126	* @param string $url Permalink to check.
127	*
128	* @return int User ID, or 0 on failure.
129	*/
130	function url_to_authorid( $url ) {
131	global $wp_rewrite;
132
133	// check if url hase the same host
134	if ( \wp_parse_url( \site_url(), \PHP_URL_HOST ) !== \wp_parse_url( $url, \PHP_URL_HOST ) ) {
135	return 0;
136	}
137
138	// first, check to see if there is a 'author=N' to match against
139	if ( \preg_match( '/[?&]author=(\d+)/i', $url, $values ) ) {
140	$id = \absint( $values[1] );
141	if ( $id ) {
142	return $id;
143	}
144	}
145
146	// check to see if we are using rewrite rules
147	$rewrite = $wp_rewrite->wp_rewrite_rules();
148
149	// not using rewrite rules, and 'author=N' method failed, so we're out of options
150	if ( empty( $rewrite ) ) {
151	return 0;
152	}
153
154	// generate rewrite rule for the author url
155	$author_rewrite = $wp_rewrite->get_author_permastruct();
156	$author_regexp = \str_replace( '%author%', '', $author_rewrite );
157
158	// match the rewrite rule with the passed url
159	if ( \preg_match( '/https?:\/\/(.+)' . \preg_quote( $author_regexp, '/' ) . '([^\/]+)/i', $url, $match ) ) {
160	$user = \get_user_by( 'slug', $match[2] );
161	if ( $user ) {
162	return $user->ID;
163	}
164	}
165
166	return 0;
167	}
168
169	/**
170	* Check for Tombstone Objects
171	*
172	* @see https://www.w3.org/TR/activitypub/#delete-activity-outbox
173	*
174	* @param WP_Error $wp_error A WP_Error-Response of an HTTP-Request
175	*
176	* @return boolean true if HTTP-Code is 410 or 404
177	*/
178	function is_tombstone( $wp_error ) {
179	if ( ! is_wp_error( $wp_error ) ) {
180	return false;
181	}
182
183	if ( in_array( (int) $wp_error->get_error_code(), array( 404, 410 ), true ) ) {
184	return true;
185	}
186
187	return false;
188	}
189
190	/**
191	* Get the REST URL relative to this plugin's namespace.
192	*
193	* @param string $path Optional. REST route path. Otherwise this plugin's namespaced root.
194	*
195	* @return string REST URL relative to this plugin's namespace.
196	*/
197	function get_rest_url_by_path( $path = '' ) {
198	// we'll handle the leading slash.
199	$path = ltrim( $path, '/' );
200	$namespaced_path = sprintf( '/%s/%s', ACTIVITYPUB_REST_NAMESPACE, $path );
201	return \get_rest_url( null, $namespaced_path );
202	}
203
204	/**
205	* Convert a string from camelCase to snake_case.
206	*
207	* @param string $string The string to convert.
208	*
209	* @return string The converted string.
210	*/
211	// phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound
212	function camel_to_snake_case( $string ) {
213	return strtolower( preg_replace( '/(?<!^)[A-Z]/', '_$0', $string ) );
214	}
215
216	/**
217	* Convert a string from snake_case to camelCase.
218	*
219	* @param string $string The string to convert.
220	*
221	* @return string The converted string.
222	*/
223	// phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound
224	function snake_to_camel_case( $string ) {
225	return lcfirst( str_replace( '_', '', ucwords( $string, '_' ) ) );
226	}
227
228	/**
229	* Escapes a Tag, to be used as a hashtag.
230	*
231	* @param string $string The string to escape.
232	*
233	* @return string The escaped hastag.
234	*/
235	function esc_hashtag( $string ) {
236
237	$hashtag = \wp_specialchars_decode( $string, ENT_QUOTES );
238	// Remove all characters that are not letters, numbers, or underscores.
239	$hashtag = \preg_replace( '/emoji-regex(*SKIP)(?!)\|[^\p{L}\p{Nd}_]+/u', '_', $hashtag );
240
241	// Capitalize every letter that is preceded by an underscore.
242	$hashtag = preg_replace_callback(
243	'/_(.)/',
244	function ( $matches ) {
245	return '' . strtoupper( $matches[1] );
246	},
247	$hashtag
248	);
249
250	// Add a hashtag to the beginning of the string.
251	$hashtag = ltrim( $hashtag, '#' );
252	$hashtag = '#' . $hashtag;
253
254	/**
255	* Allow defining your own custom hashtag generation rules.
256	*
257	* @param string $hashtag The hashtag to be returned.
258	* @param string $string The original string.
259	*/
260	$hashtag = apply_filters( 'activitypub_esc_hashtag', $hashtag, $string );
261
262	return esc_html( $hashtag );
263	}
264
265	/**
266	* Check if a request is for an ActivityPub request.
267	*
268	* @return bool False by default.
269	*/
270	function is_activitypub_request() {
271	global $wp_query;
272
273	/*
274	* ActivityPub requests are currently only made for
275	* author archives, singular posts, and the homepage.
276	*/
277	if ( ! \is_author() && ! \is_singular() && ! \is_home() && ! defined( '\REST_REQUEST' ) ) {
278	return false;
279	}
280
281	// One can trigger an ActivityPub request by adding ?activitypub to the URL.
282	// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.VariableRedeclaration
283	global $wp_query;
284	if ( isset( $wp_query->query_vars['activitypub'] ) ) {
285	return true;
286	}
287
288	/*
289	* The other (more common) option to make an ActivityPub request
290	* is to send an Accept header.
291	*/
292	if ( isset( $_SERVER['HTTP_ACCEPT'] ) ) {
293	$accept = sanitize_text_field( wp_unslash( $_SERVER['HTTP_ACCEPT'] ) );
294
295	/*
296	* $accept can be a single value, or a comma separated list of values.
297	* We want to support both scenarios,
298	* and return true when the header includes at least one of the following:
299	* - application/activity+json
300	* - application/ld+json
301	* - application/json
302	*/
303	if ( preg_match( '/(application\/(ld\+json\|activity\+json\|json))/i', $accept ) ) {
304	return true;
305	}
306	}
307
308	return false;
309	}
310
311	/**
312	* This function checks if a user is disabled for ActivityPub.
313	*
314	* @param int $user_id The User-ID.
315	*
316	* @return boolean True if the user is disabled, false otherwise.
317	*/
318	function is_user_disabled( $user_id ) {
319	$return = false;
320
321	switch ( $user_id ) {
322	// if the user is the application user, it's always enabled.
323	case \Activitypub\Collection\Users::APPLICATION_USER_ID:
324	$return = false;
325	break;
326	// if the user is the blog user, it's only enabled in single-user mode.
327	case \Activitypub\Collection\Users::BLOG_USER_ID:
328	if ( is_user_type_disabled( 'blog' ) ) {
329	$return = true;
330	break;
331	}
332
333	$return = false;
334	break;
335	// if the user is any other user, it's enabled if it can publish posts.
336	default:
337	if ( ! \get_user_by( 'id', $user_id ) ) {
338	$return = true;
339	break;
340	}
341
342	if ( is_user_type_disabled( 'user' ) ) {
343	$return = true;
344	break;
345	}
346
347	if ( ! \user_can( $user_id, 'publish_posts' ) ) {
348	$return = true;
349	break;
350	}
351
352	$return = false;
353	break;
354	}
355
356	return apply_filters( 'activitypub_is_user_disabled', $return, $user_id );
357	}
358
359	/**
360	* Checks if a User-Type is disabled for ActivityPub.
361	*
362	* This function is used to check if the 'blog' or 'user'
363	* type is disabled for ActivityPub.
364	*
365	* @param enum $type Can be 'blog' or 'user'.
366	*
367	* @return boolean True if the user type is disabled, false otherwise.
368	*/
369	function is_user_type_disabled( $type ) {
370	switch ( $type ) {
371	case 'blog':
372	if ( \defined( 'ACTIVITYPUB_SINGLE_USER_MODE' ) ) {
373	if ( ACTIVITYPUB_SINGLE_USER_MODE ) {
374	$return = false;
375	break;
376	}
377	}
378
379	if ( \defined( 'ACTIVITYPUB_DISABLE_BLOG_USER' ) ) {
380	$return = ACTIVITYPUB_DISABLE_BLOG_USER;
381	break;
382	}
383
384	if ( '1' !== \get_option( 'activitypub_enable_blog_user', '0' ) ) {
385	$return = true;
386	break;
387	}
388
389	$return = false;
390	break;
391	case 'user':
392	if ( \defined( 'ACTIVITYPUB_SINGLE_USER_MODE' ) ) {
393	if ( ACTIVITYPUB_SINGLE_USER_MODE ) {
394	$return = true;
395	break;
396	}
397	}
398
399	if ( \defined( 'ACTIVITYPUB_DISABLE_USER' ) ) {
400	$return = ACTIVITYPUB_DISABLE_USER;
401	break;
402	}
403
404	if ( '1' !== \get_option( 'activitypub_enable_users', '1' ) ) {
405	$return = true;
406	break;
407	}
408
409	$return = false;
410	break;
411	default:
412	$return = new WP_Error( 'activitypub_wrong_user_type', __( 'Wrong user type', 'activitypub' ), array( 'status' => 400 ) );
413	break;
414	}
415
416	return apply_filters( 'activitypub_is_user_type_disabled', $return, $type );
417	}
418
419	/**
420	* Check if the blog is in single-user mode.
421	*
422	* @return boolean True if the blog is in single-user mode, false otherwise.
423	*/
424	function is_single_user() {
425	if (
426	false === is_user_type_disabled( 'blog' ) &&
427	true === is_user_type_disabled( 'user' )
428	) {
429	return true;
430	}
431
432	return false;
433	}
434
435	/**
436	* Check if a site supports the block editor.
437	*
438	* @return boolean True if the site supports the block editor, false otherwise.
439	*/
440	function site_supports_blocks() {
441	if ( \version_compare( \get_bloginfo( 'version' ), '5.9', '<' ) ) {
442	return false;
443	}
444
445	if ( ! \function_exists( 'register_block_type_from_metadata' ) ) {
446	return false;
447	}
448
449	/**
450	* Allow plugins to disable block editor support,
451	* thus disabling blocks registered by the ActivityPub plugin.
452	*
453	* @param boolean $supports_blocks True if the site supports the block editor, false otherwise.
454	*/
455	return apply_filters( 'activitypub_site_supports_blocks', true );
456	}
457
458	/**
459	* Check if data is valid JSON.
460	*
461	* @param string $data The data to check.
462	*
463	* @return boolean True if the data is JSON, false otherwise.
464	*/
465	function is_json( $data ) {
466	return \is_array( \json_decode( $data, true ) ) ? true : false;
467	}
468
469	/**
470	* Check if a blog is public based on the `blog_public` option
471	*
472	* @return bollean True if public, false if not
473	*/
474	function is_blog_public() {
475	return (bool) apply_filters( 'activitypub_is_blog_public', \get_option( 'blog_public', 1 ) );
476	}
477