activitypub / includes / class-mention.php

class-mention.php in ActivityPub 2.5.0, at includes/class-mention.php

184 lines 4.9 KB

Raw Download Zip

1	<?php
2	namespace Activitypub;
3
4	use WP_Error;
5	use Activitypub\Webfinger;
6
7	use function Activitypub\object_to_uri;
8
9	/**
10	* ActivityPub Mention Class
11	*
12	* @author Alex Kirk
13	*/
14	class Mention {
15	/**
16	* Initialize the class, registering WordPress hooks
17	*/
18	public static function init() {
19	\add_filter( 'the_content', array( self::class, 'the_content' ), 99, 1 );
20	\add_filter( 'comment_text', array( self::class, 'the_content' ), 10, 1 );
21	\add_filter( 'activitypub_extract_mentions', array( self::class, 'extract_mentions' ), 99, 2 );
22	}
23
24	/**
25	* Filter to replace the mentions in the content with links
26	*
27	* @param string $the_content the post-content
28	*
29	* @return string the filtered post-content
30	*/
31	public static function the_content( $the_content ) {
32	// small protection against execution timeouts: limit to 1 MB
33	if ( mb_strlen( $the_content ) > MB_IN_BYTES ) {
34	return $the_content;
35	}
36	$tag_stack = array();
37	$protected_tags = array(
38	'pre',
39	'code',
40	'textarea',
41	'style',
42	'a',
43	);
44	$content_with_links = '';
45	$in_protected_tag = false;
46	foreach ( wp_html_split( $the_content ) as $chunk ) {
47	if ( preg_match( '#^<!--[\s\S]*-->$#i', $chunk, $m ) ) {
48	$content_with_links .= $chunk;
49	continue;
50	}
51
52	if ( preg_match( '#^<(/)?([a-z-]+)\b[^>]*>$#i', $chunk, $m ) ) {
53	$tag = strtolower( $m[2] );
54	if ( '/' === $m[1] ) {
55	// Closing tag.
56	$i = array_search( $tag, $tag_stack );
57	// We can only remove the tag from the stack if it is in the stack.
58	if ( false !== $i ) {
59	$tag_stack = array_slice( $tag_stack, 0, $i );
60	}
61	} else {
62	// Opening tag, add it to the stack.
63	$tag_stack[] = $tag;
64	}
65
66	// If we're in a protected tag, the tag_stack contains at least one protected tag string.
67	// The protected tag state can only change when we encounter a start or end tag.
68	$in_protected_tag = array_intersect( $tag_stack, $protected_tags );
69
70	// Never inspect tags.
71	$content_with_links .= $chunk;
72	continue;
73	}
74
75	if ( $in_protected_tag ) {
76	// Don't inspect a chunk inside an inspected tag.
77	$content_with_links .= $chunk;
78	continue;
79	}
80
81	// Only reachable when there is no protected tag in the stack.
82	$content_with_links .= \preg_replace_callback( '/@' . ACTIVITYPUB_USERNAME_REGEXP . '/', array( self::class, 'replace_with_links' ), $chunk );
83	}
84
85	return $content_with_links;
86	}
87
88	/**
89	* A callback for preg_replace to build the user links
90	*
91	* @param array $result the preg_match results
92	*
93	* @return string the final string
94	*/
95	public static function replace_with_links( $result ) {
96	$metadata = get_remote_metadata_by_actor( $result[0] );
97
98	if (
99	! empty( $metadata ) &&
100	! is_wp_error( $metadata ) &&
101	( ! empty( $metadata['id'] ) \|\| ! empty( $metadata['url'] ) )
102	) {
103	$username = ltrim( $result[0], '@' );
104	if ( ! empty( $metadata['name'] ) ) {
105	$username = $metadata['name'];
106	}
107	if ( ! empty( $metadata['preferredUsername'] ) ) {
108	$username = $metadata['preferredUsername'];
109	}
110
111	$url = isset( $metadata['url'] ) ? object_to_uri( $metadata['url'] ) : object_to_uri( $metadata['id'] );
112
113	return \sprintf( '<a rel="mention" class="u-url mention" href="%s">@<span>%s</span></a>', esc_url( $url ), esc_html( $username ) );
114	}
115
116	return $result[0];
117	}
118
119	/**
120	* Get the Inboxes for the mentioned Actors
121	*
122	* @param array $mentioned The list of Actors that were mentioned
123	*
124	* @return array The list of Inboxes
125	*/
126	public static function get_inboxes( $mentioned ) {
127	$inboxes = array();
128
129	foreach ( $mentioned as $actor ) {
130	$inbox = self::get_inbox_by_mentioned_actor( $actor );
131
132	if ( ! is_wp_error( $inbox ) && $inbox ) {
133	$inboxes[] = $inbox;
134	}
135	}
136
137	return $inboxes;
138	}
139
140	/**
141	* Get the inbox from the Remote-Profile of a mentioned Actor
142	*
143	* @param string $actor The Actor-URL
144	*
145	* @return string The Inbox-URL
146	*/
147	public static function get_inbox_by_mentioned_actor( $actor ) {
148	$metadata = get_remote_metadata_by_actor( $actor );
149
150	if ( \is_wp_error( $metadata ) ) {
151	return $metadata;
152	}
153
154	if ( isset( $metadata['endpoints'] ) && isset( $metadata['endpoints']['sharedInbox'] ) ) {
155	return $metadata['endpoints']['sharedInbox'];
156	}
157
158	if ( \array_key_exists( 'inbox', $metadata ) ) {
159	return $metadata['inbox'];
160	}
161
162	return new WP_Error( 'activitypub_no_inbox', \__( 'No "Inbox" found', 'activitypub' ), $metadata );
163	}
164
165	/**
166	* Extract the mentions from the post_content.
167	*
168	* @param array $mentions The already found mentions.
169	* @param string $post_content The post content.
170	*
171	* @return mixed The discovered mentions.
172	*/
173	public static function extract_mentions( $mentions, $post_content ) {
174	\preg_match_all( '/@' . ACTIVITYPUB_USERNAME_REGEXP . '/i', $post_content, $matches );
175	foreach ( $matches[0] as $match ) {
176	$link = Webfinger::resolve( $match );
177	if ( ! is_wp_error( $link ) ) {
178	$mentions[ $match ] = $link;
179	}
180	}
181	return $mentions;
182	}
183	}
184