activitypub / includes / functions-activity.php

functions-activity.php in ActivityPub 9.0.0, at includes/functions-activity.php

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1	<?php
2	/**
3	* Activity functions.
4	*
5	* Functions for working with ActivityPub activities, objects, and actors.
6	*
7	* @package Activitypub
8	*/
9
10	namespace Activitypub;
11
12	use Activitypub\Activity\Activity;
13	use Activitypub\Activity\Actor;
14	use Activitypub\Activity\Base_Object;
15
16	/**
17	* Returns the ActivityPub default JSON-context.
18	*
19	* @return array The activitypub context.
20	*
21	* @deprecated 7.6.0 Use the respective context function instead.
22	*/
23	function get_context() {
24	\_deprecated_function( __FUNCTION__, '7.6.0', 'Use the respective context function instead.' );
25
26	$context = Activity::JSON_LD_CONTEXT;
27
28	/**
29	* Filters the ActivityPub JSON-LD context.
30	*
31	* This filter allows developers to modify or extend the JSON-LD context used
32	* in ActivityPub responses. The context defines the vocabulary and terms used
33	* in the ActivityPub JSON objects.
34	*
35	* @param array $context The default ActivityPub JSON-LD context array.
36	*/
37	return \apply_filters( 'activitypub_json_context', $context );
38	}
39
40	/**
41	* Extract recipient URLs from Activity object.
42	*
43	* @param array $data The Activity object as array.
44	*
45	* @return array The list of user URLs.
46	*/
47	function extract_recipients_from_activity( $data ) {
48	$recipient_items = array();
49
50	foreach ( array( 'to', 'bto', 'cc', 'bcc', 'audience' ) as $i ) {
51	$recipient_items = \array_merge( $recipient_items, extract_recipients_from_activity_property( $i, $data ) );
52	}
53
54	return \array_unique( $recipient_items );
55	}
56
57	/**
58	* Extract recipient URLs from a specific property of an Activity object.
59	*
60	* Checks the activity level first, then falls back to the object property,
61	* and finally checks the instrument property (used by QuoteRequest activities).
62	*
63	* @param string $property The property to extract recipients from (e.g., 'to', 'cc').
64	* @param array $data The Activity object as array.
65	*
66	* @return array The list of user URLs.
67	*/
68	function extract_recipients_from_activity_property( $property, $data ) {
69	$recipients = array();
70
71	if ( ! empty( $data[ $property ] ) ) {
72	$recipients = $data[ $property ];
73	} elseif ( ! empty( $data['object'][ $property ] ) ) {
74	$recipients = $data['object'][ $property ];
75	} elseif ( ! empty( $data['instrument'][ $property ] ) ) {
76	// QuoteRequest activities have addressing in the instrument (the quoting Note).
77	$recipients = $data['instrument'][ $property ];
78	}
79
80	$recipients = \array_map( '\Activitypub\object_to_uri', (array) $recipients );
81
82	return \array_unique( \array_filter( $recipients ) );
83	}
84
85	/**
86	* Determine the visibility of the activity based on its recipients.
87	*
88	* @param array $activity The activity data.
89	*
90	* @return string One of ACTIVITYPUB_CONTENT_VISIBILITY_PUBLIC,
91	* ACTIVITYPUB_CONTENT_VISIBILITY_QUIET_PUBLIC, or
92	* ACTIVITYPUB_CONTENT_VISIBILITY_PRIVATE.
93	*/
94	function get_activity_visibility( $activity ) {
95	// Set default visibility for specific activity types.
96	if ( ! empty( $activity['type'] ) && in_array( $activity['type'], array( 'Accept', 'Delete', 'Follow', 'Reject', 'Undo' ), true ) ) {
97	return ACTIVITYPUB_CONTENT_VISIBILITY_PRIVATE;
98	}
99
100	// Check 'to' field for public visibility.
101	$to = extract_recipients_from_activity_property( 'to', $activity );
102	if ( ! empty( array_intersect( $to, ACTIVITYPUB_PUBLIC_AUDIENCE_IDENTIFIERS ) ) ) {
103	return ACTIVITYPUB_CONTENT_VISIBILITY_PUBLIC;
104	}
105
106	// Check 'cc' field for quiet public visibility.
107	$cc = extract_recipients_from_activity_property( 'cc', $activity );
108	if ( ! empty( array_intersect( $cc, ACTIVITYPUB_PUBLIC_AUDIENCE_IDENTIFIERS ) ) ) {
109	return ACTIVITYPUB_CONTENT_VISIBILITY_QUIET_PUBLIC;
110	}
111
112	return ACTIVITYPUB_CONTENT_VISIBILITY_PRIVATE;
113	}
114
115	/**
116	* Check if passed Activity is Public.
117	*
118	* @see https://github.com/w3c/activitypub/issues/404#issuecomment-2926310561
119	* @see https://www.w3.org/TR/activitypub/#delivery (Section 7.1, "Silent and private activities")
120	*
121	* @param Base_Object\|array $data The Activity object as Base_Object or array.
122	*
123	* @return boolean True if public, false if not.
124	*/
125	function is_activity_public( $data ) {
126	if ( $data instanceof Base_Object ) {
127	$data = $data->to_array();
128	}
129
130	$recipients = extract_recipients_from_activity( $data );
131
132	if ( empty( $recipients ) ) {
133	return false;
134	}
135
136	return ! empty( array_intersect( $recipients, ACTIVITYPUB_PUBLIC_AUDIENCE_IDENTIFIERS ) );
137	}
138
139	/**
140	* Check if passed Activity is a reply.
141	*
142	* @param array $data The Activity object as array.
143	*
144	* @return boolean True if a reply, false if not.
145	*/
146	function is_activity_reply( $data ) {
147	return ! empty( $data['object']['inReplyTo'] );
148	}
149
150	/**
151	* Check if passed Activity is a quote.
152	*
153	* Checks for quote properties: quote, quoteUrl, quoteUri, or _misskey_quote.
154	*
155	* @param array $data The Activity object as array.
156	*
157	* @return boolean True if a quote, false if not.
158	*/
159	function is_quote_activity( $data ) {
160	return ! empty( $data['object']['quote'] ) \|\|
161	! empty( $data['object']['quoteUrl'] ) \|\|
162	! empty( $data['object']['quoteUri'] ) \|\|
163	! empty( $data['object']['_misskey_quote'] );
164	}
165
166	/**
167	* Get the URI of an ActivityPub object.
168	*
169	* @param array\|string $data The ActivityPub object.
170	*
171	* @return string\|null The URI of the ActivityPub object.
172	*/
173	function object_to_uri( $data ) {
174	// Check whether it is already simple.
175	if ( ! $data \|\| is_string( $data ) ) {
176	return $data;
177	}
178
179	if ( is_object( $data ) ) {
180	$data = $data->to_array();
181	}
182
183	/*
184	* Check if it is a list, then take first item.
185	* This plugin does not support collections.
186	*/
187	if ( array_is_list( $data ) ) {
188	$data = $data[0];
189	}
190
191	// Check if it is simplified now.
192	if ( is_string( $data ) ) {
193	return $data;
194	}
195
196	$type = 'Object';
197	if ( isset( $data['type'] ) ) {
198	$type = $data['type'];
199	}
200
201	// Return part of Object that makes most sense.
202	switch ( $type ) {
203	case 'Audio': // See https://www.w3.org/TR/activitystreams-vocabulary/#dfn-audio.
204	case 'Document': // See https://www.w3.org/TR/activitystreams-vocabulary/#dfn-document.
205	case 'Image': // See https://www.w3.org/TR/activitystreams-vocabulary/#dfn-image.
206	case 'Video': // See https://www.w3.org/TR/activitystreams-vocabulary/#dfn-video.
207	$data = object_to_uri( $data['url'] );
208	break;
209
210	case 'Link': // See https://www.w3.org/TR/activitystreams-vocabulary/#dfn-link.
211	case 'Mention': // See https://www.w3.org/TR/activitystreams-vocabulary/#dfn-mention.
212	$data = $data['href'];
213	break;
214
215	case 'FeaturedItem': // See https://github.com/mastodon/featured_collections/pull/1.
216	$data = object_to_uri( $data['featuredObject'] ?? null );
217	break;
218
219	default:
220	if ( isset( $data['id'] ) ) {
221	$data = $data['id'];
222	} elseif ( isset( $data['url'] ) ) {
223	$data = object_to_uri( $data['url'] );
224	} elseif ( isset( $data['href'] ) ) {
225	$data = $data['href'];
226	} else {
227	$data = null;
228	}
229	break;
230	}
231
232	return $data;
233	}
234
235	/**
236	* Check if an `$data` is an Activity.
237	*
238	* @see https://www.w3.org/ns/activitystreams#activities
239	*
240	* @param array\|object\|string $data The data to check.
241	*
242	* @return boolean True if the `$data` is an Activity, false otherwise.
243	*/
244	function is_activity( $data ) {
245	/**
246	* Filters the activity types.
247	*
248	* @param array $types The activity types.
249	*/
250	$types = apply_filters( 'activitypub_activity_types', Activity::TYPES );
251
252	return _is_type_of( $data, $types );
253	}
254
255	/**
256	* Check if an `$data` is an Activity Object.
257	*
258	* @see https://www.w3.org/TR/activitystreams-vocabulary/#object-types
259	*
260	* @param array\|object\|string $data The data to check.
261	*
262	* @return boolean True if the `$data` is an Activity Object, false otherwise.
263	*/
264	function is_activity_object( $data ) {
265	/**
266	* Filters the activity object types.
267	*
268	* @param array $types The activity object types.
269	*/
270	$types = \apply_filters( 'activitypub_activity_object_types', Base_Object::TYPES );
271
272	return _is_type_of( $data, $types );
273	}
274
275	/**
276	* Check if an `$data` is an Actor.
277	*
278	* @see https://www.w3.org/ns/activitystreams#actor
279	*
280	* @param array\|object\|string $data The data to check.
281	*
282	* @return boolean True if the `$data` is an Actor, false otherwise.
283	*/
284	function is_actor( $data ) {
285	/**
286	* Filters the actor types.
287	*
288	* @param array $types The actor types.
289	*/
290	$types = apply_filters( 'activitypub_actor_types', Actor::TYPES );
291
292	return _is_type_of( $data, $types );
293	}
294
295	/**
296	* Check if an `$data` is a Collection.
297	*
298	* @see https://www.w3.org/ns/activitystreams#collections
299	*
300	* @param array\|object\|string $data The data to check.
301	*
302	* @return boolean True if the `$data` is a Collection, false otherwise.
303	*/
304	function is_collection( $data ) {
305	/**
306	* Filters the collection types.
307	*
308	* @param array $types The collection types.
309	*/
310	$types = apply_filters( 'activitypub_collection_types', array( 'Collection', 'OrderedCollection', 'CollectionPage', 'OrderedCollectionPage' ) );
311
312	return _is_type_of( $data, $types );
313	}
314
315	/**
316	* Private helper to check if $data is of a given type set.
317	*
318	* @param array\|object\|string $data The data to check.
319	* @param array $types The types to check against.
320	*
321	* @return boolean True if $data is of one of the types, false otherwise.
322	*/
323	function _is_type_of( $data, $types ) {
324	if ( is_string( $data ) ) {
325	return in_array( $data, $types, true );
326	}
327
328	if ( is_array( $data ) && isset( $data['type'] ) ) {
329	return in_array( $data['type'], $types, true );
330	}
331
332	if ( $data instanceof Base_Object ) {
333	return in_array( $data->get_type(), $types, true );
334	}
335
336	return false;
337	}
338