activitypub / includes / functions-federation.php

functions-federation.php in ActivityPub 9.2.0, at includes/functions-federation.php

276 lines 9.1 KB

Raw Download Zip

1	<?php
2	/**
3	* Federation functions.
4	*
5	* Functions for managing federation state, outbox, and follow/unfollow operations.
6	*
7	* @package Activitypub
8	*/
9
10	namespace Activitypub;
11
12	use Activitypub\Activity\Activity;
13	use Activitypub\Collection\Actors;
14	use Activitypub\Collection\Following;
15	use Activitypub\Collection\Outbox;
16	use Activitypub\Collection\Remote_Actors;
17	use Activitypub\Transformer\Factory as Transformer_Factory;
18
19	/**
20	* Set the federation state of a WordPress object.
21	*
22	* @param \WP_Comment\|\WP_Post $wp_object The WordPress object.
23	* @param string $state The state of the object.
24	*/
25	function set_wp_object_state( $wp_object, $state ) {
26	if ( $wp_object instanceof \WP_Post ) {
27	$meta_type = 'post';
28	$object_id = $wp_object->ID;
29	} elseif ( $wp_object instanceof \WP_Comment ) {
30	$meta_type = 'comment';
31	$object_id = $wp_object->comment_ID;
32	} else {
33	/**
34	* Allow plugins to mark WordPress objects as federated.
35	*
36	* @param \WP_Comment\|\WP_Post $wp_object The WordPress object.
37	*/
38	\do_action( 'activitypub_mark_wp_object_as_federated', $wp_object );
39	return;
40	}
41
42	\update_metadata( $meta_type, $object_id, 'activitypub_status', $state );
43
44	if ( ACTIVITYPUB_OBJECT_STATE_DELETED === $state ) {
45	\update_metadata( $meta_type, $object_id, 'activitypub_deleted_at', \time() );
46	} else {
47	\delete_metadata( $meta_type, $object_id, 'activitypub_deleted_at' );
48	}
49	}
50
51	/**
52	* Get the federation state of a WordPress object.
53	*
54	* @param \WP_Comment\|\WP_Post $wp_object The WordPress object.
55	*
56	* @return string\|false The state of the object or false if not found.
57	*/
58	function get_wp_object_state( $wp_object ) {
59	if ( $wp_object instanceof \WP_Post ) {
60	$meta_type = 'post';
61	$object_id = $wp_object->ID;
62	} elseif ( $wp_object instanceof \WP_Comment ) {
63	$meta_type = 'comment';
64	$object_id = $wp_object->comment_ID;
65	} else {
66	/**
67	* Allow plugins to get the federation state of a WordPress object.
68	*
69	* @param false $state The state of the object.
70	* @param \WP_Comment\|\WP_Post $wp_object The WordPress object.
71	*/
72	return \apply_filters( 'activitypub_get_wp_object_state', false, $wp_object );
73	}
74
75	return \get_metadata( $meta_type, $object_id, 'activitypub_status', true );
76	}
77
78	/**
79	* Check if an ID is from the same domain as the site.
80	*
81	* @param string $id The ID URI to check.
82	*
83	* @return boolean True if the ID is a self-ping, false otherwise.
84	*/
85	function is_self_ping( $id ) {
86	$query_string = \wp_parse_url( $id, PHP_URL_QUERY );
87
88	if ( ! $query_string ) {
89	return false;
90	}
91
92	$query = array();
93	\parse_str( $query_string, $query );
94
95	if (
96	is_same_domain( $id ) &&
97	\in_array( 'c', \array_keys( $query ), true )
98	) {
99	return true;
100	}
101
102	return false;
103	}
104
105	/**
106	* Add an object to the outbox.
107	*
108	* @param mixed $data The object to add to the outbox.
109	* @param string\|null $activity_type Optional. The type of the Activity or null if `$data` is an Activity. Default null.
110	* @param integer $user_id Optional. The User-ID. Default 0.
111	* @param string $content_visibility Optional. The visibility of the content. See `constants.php` for possible values: `ACTIVITYPUB_CONTENT_VISIBILITY_*`. Default null.
112	*
113	* @return boolean\|int The ID of the outbox item or false on failure.
114	*/
115	function add_to_outbox( $data, $activity_type = null, $user_id = 0, $content_visibility = null ) {
116	// If the user is disabled, fall back to the blog user when available.
117	if ( ! user_can_activitypub( $user_id ) ) {
118	if ( user_can_activitypub( Actors::BLOG_USER_ID ) ) {
119	$user_id = Actors::BLOG_USER_ID;
120	} else {
121	return false;
122	}
123	}
124
125	/*
126	* Refuse to Update an object that is already deleted from the Fediverse. An
127	* explicit Update (e.g. `wp activitypub post update` or a third-party caller)
128	* on a soft-deleted post would only federate a Tombstone, and — worse — would
129	* reset the object's state to "federated" below, so a later re-publish would
130	* skip the Create that cancels the still-pending Delete and the post could be
131	* torn down after it is public again. Re-publishing is the supported way to
132	* bring a deleted object back, and that emits a Create, not an Update.
133	*/
134	if ( 'Update' === $activity_type && ACTIVITYPUB_OBJECT_STATE_DELETED === get_wp_object_state( $data ) ) {
135	return new \WP_Error(
136	'activitypub_object_deleted',
137	\__( 'Cannot send an Update for an object that has been deleted from the Fediverse. Re-publish it instead.', 'activitypub' ),
138	array( 'status' => 409 )
139	);
140	}
141
142	$transformer = Transformer_Factory::get_transformer( $data );
143
144	if ( ! $transformer \|\| \is_wp_error( $transformer ) ) {
145	return false;
146	}
147
148	if ( $content_visibility ) {
149	$transformer->set_content_visibility( $content_visibility );
150	} else {
151	$content_visibility = $transformer->get_content_visibility();
152	}
153
154	if ( $activity_type ) {
155	$activity = $transformer->to_activity( $activity_type );
156	$activity->set_actor( Actors::get_by_id( $user_id )->get_id() );
157	} else {
158	$activity = $transformer->to_object();
159	}
160
161	if ( ! $activity \|\| \is_wp_error( $activity ) ) {
162	/**
163	* Action triggered when adding an object to the outbox fails.
164	*
165	* @param \WP_Error $activity The error object or false.
166	* @param mixed $data The object that failed to be added to the outbox.
167	* @param string\|null $activity_type The type of the Activity or null if `$data` is an Activity.
168	* @param int $user_id The User ID.
169	* @param string $content_visibility The visibility of the content. See `constants.php` for possible values: `ACTIVITYPUB_CONTENT_VISIBILITY_*`.
170	*/
171	\do_action( 'activitypub_add_to_outbox_failed', $activity, $data, $activity_type, $user_id, $content_visibility );
172
173	return false;
174	}
175
176	$outbox_activity_id = Outbox::add( $activity, $user_id, $content_visibility );
177
178	if ( ! $outbox_activity_id \|\| \is_wp_error( $outbox_activity_id ) ) {
179	/**
180	* Action triggered when adding an object to the outbox fails.
181	*
182	* @param false\|\WP_Error $outbox_activity_id The error object or false.
183	* @param mixed $data The object that failed to be added to the outbox.
184	* @param string\|null $activity_type The type of the Activity or null if `$data` is an Activity.
185	* @param int $user_id The User ID.
186	* @param string $content_visibility The visibility of the content. See `constants.php` for possible values: `ACTIVITYPUB_CONTENT_VISIBILITY_*`.
187	*/
188	\do_action( 'activitypub_add_to_outbox_failed', $outbox_activity_id, $data, $activity_type, $user_id, $content_visibility );
189
190	return false;
191	}
192
193	/**
194	* Action triggered after an object has been added to the outbox.
195	*
196	* @param int $outbox_activity_id The ID of the outbox item.
197	* @param Activity $activity The activity object.
198	* @param int $user_id The User-ID.
199	* @param string $content_visibility The visibility of the content. See `constants.php` for possible values: `ACTIVITYPUB_CONTENT_VISIBILITY_*`.
200	*/
201	\do_action( 'post_activitypub_add_to_outbox', $outbox_activity_id, $activity, $user_id, $content_visibility );
202
203	// Update state based on activity.
204	$state_map = array(
205	'Create' => ACTIVITYPUB_OBJECT_STATE_FEDERATED,
206	'Update' => ACTIVITYPUB_OBJECT_STATE_FEDERATED,
207	'Delete' => ACTIVITYPUB_OBJECT_STATE_DELETED,
208	);
209
210	if ( $activity_type && isset( $state_map[ $activity_type ] ) ) {
211	set_wp_object_state( $data, $state_map[ $activity_type ] );
212	}
213
214	return $outbox_activity_id;
215	}
216
217	/**
218	* Follow a user.
219	*
220	* @param string\|int $remote_actor The Actor URL, WebFinger Resource or Post-ID of the remote Actor.
221	* @param int $user_id The ID of the WordPress User.
222	*
223	* @return int\|\WP_Error The Outbox ID on success or a WP_Error on failure.
224	*/
225	function follow( $remote_actor, $user_id ) {
226	if ( \is_numeric( $remote_actor ) ) {
227	return Following::follow( $remote_actor, $user_id );
228	}
229
230	if ( ! \filter_var( $remote_actor, FILTER_VALIDATE_URL ) ) {
231	$remote_actor = Webfinger::resolve( $remote_actor );
232	}
233
234	if ( \is_wp_error( $remote_actor ) ) {
235	return $remote_actor;
236	}
237
238	$remote_actor_post = Remote_Actors::fetch_by_uri( $remote_actor );
239
240	if ( \is_wp_error( $remote_actor_post ) ) {
241	return $remote_actor_post;
242	}
243
244	return Following::follow( $remote_actor_post, $user_id );
245	}
246
247	/**
248	* Unfollow a user.
249	*
250	* @param string\|int $remote_actor The Actor URL, WebFinger Resource or Post-ID of the remote Actor.
251	* @param int $user_id The ID of the WordPress User.
252	*
253	* @return int\|\WP_Error The ID of the Undo outbox item, 0 if no matching Follow outbox was found, or WP_Error on failure.
254	*/
255	function unfollow( $remote_actor, $user_id ) {
256	if ( \is_numeric( $remote_actor ) ) {
257	return Following::unfollow( $remote_actor, $user_id );
258	}
259
260	if ( ! \filter_var( $remote_actor, FILTER_VALIDATE_URL ) ) {
261	$remote_actor = Webfinger::resolve( $remote_actor );
262	}
263
264	if ( \is_wp_error( $remote_actor ) ) {
265	return $remote_actor;
266	}
267
268	$remote_actor_post = Remote_Actors::fetch_by_uri( $remote_actor );
269
270	if ( \is_wp_error( $remote_actor_post ) ) {
271	return $remote_actor_post;
272	}
273
274	return Following::unfollow( $remote_actor_post, $user_id );
275	}
276