activitypub / includes / class-emoji.php

class-emoji.php in ActivityPub 9.3.0, at includes/class-emoji.php

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1	<?php
2	/**
3	* ActivityPub Emoji file.
4	*
5	* @package Activitypub
6	*/
7
8	namespace Activitypub;
9
10	/**
11	* Handles custom emoji processing for ActivityPub content.
12	*
13	* Wraps emoji shortcodes with block patterns at insert time. The blocks are
14	* rendered at display time by WordPress (posts) or via do_blocks() (comments).
15	*
16	* Also handles emoji replacement for comment author names (which don't use blocks).
17	*
18	* @see https://codeberg.org/fediverse/fep/src/branch/main/fep/9098/fep-9098.md FEP-9098: Custom Emojis
19	*/
20	class Emoji {
21
22	/**
23	* Wrap emoji shortcodes in content with block patterns.
24	*
25	* Called at insert time to wrap emoji shortcodes with activitypub/emoji blocks.
26	* The blocks are rendered at display time via their render_callback.
27	*
28	* @param string $content The content to process.
29	* @param array $activity The activity containing emoji definitions in 'tag'.
30	*
31	* @return string The content with wrapped emoji.
32	*/
33	public static function wrap_in_content( $content, $activity ) {
34	if ( empty( $content ) \|\| empty( $activity['tag'] ) \|\| ! \is_array( $activity['tag'] ) ) {
35	return $content;
36	}
37
38	foreach ( $activity['tag'] as $tag ) {
39	if ( ! \is_array( $tag ) \|\| ! isset( $tag['type'] ) \|\| 'Emoji' !== $tag['type'] \|\| empty( $tag['name'] ) ) {
40	continue;
41	}
42
43	$url = object_to_uri( $tag['icon'] ?? null );
44	if ( empty( $url ) ) {
45	continue;
46	}
47
48	$shortcode = $tag['name'];
49	$block_attrs = array( 'url' => \esc_url( $url ) );
50
51	if ( ! empty( $tag['updated'] ) && \is_string( $tag['updated'] ) && \strtotime( $tag['updated'] ) ) {
52	$block_attrs['updated'] = \sanitize_text_field( $tag['updated'] );
53	}
54
55	$wrapped = \sprintf(
56	'<!-- wp:activitypub/emoji %s -->%s<!-- /wp:activitypub/emoji -->',
57	\wp_json_encode( $block_attrs ),
58	$shortcode
59	);
60
61	// Case-insensitive replacement, avoid already wrapped shortcodes.
62	$pattern = '/(?<!-->)' . \preg_quote( $shortcode, '/' ) . '(?!<!-- \/wp:activitypub\/emoji -->)/i';
63	$content = \preg_replace_callback(
64	$pattern,
65	function () use ( $wrapped ) {
66	return $wrapped;
67	},
68	$content
69	);
70	}
71
72	return $content;
73	}
74
75	/**
76	* Generate an emoji img tag.
77	*
78	* @param string $url The emoji image URL.
79	* @param string $name The emoji name (without colons).
80	*
81	* @return string The emoji img tag HTML.
82	*/
83	public static function get_img_tag( $url, $name ) {
84	return \sprintf(
85	'<img src="%s" alt="%s" title="%s" class="emoji" width="20" height="20" draggable="false" />',
86	\esc_url( $url ),
87	\esc_attr( $name ),
88	\esc_attr( $name )
89	);
90	}
91
92	/**
93	* Get the allowed HTML structure for emoji img tags.
94	*
95	* Used by Comment class for KSES validation of emoji in author names.
96	*
97	* @return array The allowed HTML structure for use with wp_kses.
98	*/
99	public static function get_kses_allowed_html() {
100	return array(
101	'img' => array(
102	'class' => array(
103	'required' => true,
104	'values' => array( 'emoji' ),
105	),
106	'src' => array(
107	'required' => true,
108	'value_callback' => array( self::class, 'validate_emoji_src' ),
109	),
110	'alt' => array( 'required' => true ),
111	'title' => array( 'required' => true ),
112	'height' => array(
113	'required' => true,
114	'values' => array( '20' ),
115	),
116	'width' => array(
117	'required' => true,
118	'values' => array( '20' ),
119	),
120	'draggable' => array(
121	'required' => true,
122	'values' => array( 'false' ),
123	),
124	),
125	);
126	}
127
128	/**
129	* Validate emoji src attribute for wp_kses.
130	*
131	* By default, only allows locally cached emoji URLs for privacy.
132	* Remote URLs are only allowed when caching is explicitly disabled.
133	*
134	* @param string $value The src attribute value.
135	*
136	* @return bool True if the src is valid, false otherwise.
137	*/
138	public static function validate_emoji_src( $value ) {
139	$upload_dir = \wp_upload_dir();
140	$emoji_base = $upload_dir['baseurl'] . '/activitypub/emoji/';
141
142	// Allow local cached emoji.
143	if ( \str_starts_with( $value, $emoji_base ) ) {
144	return true;
145	}
146
147	// Only allow remote URLs when caching is explicitly disabled.
148	// This protects user privacy by defaulting to local-only emoji.
149	$allow_remote = ! Cache::is_enabled();
150
151	// Validate the URL format if remote is allowed.
152	if ( $allow_remote ) {
153	$allow_remote = (bool) \wp_http_validate_url( $value );
154	}
155
156	/**
157	* Filters whether a remote emoji URL is valid.
158	*
159	* Use this filter to explicitly allow remote emoji URLs when needed
160	* (e.g., for CDN proxying).
161	*
162	* @since 5.6.0
163	*
164	* @param bool $valid Whether the URL is valid.
165	* @param string $value The emoji src URL.
166	*/
167	return \apply_filters( 'activitypub_validate_emoji_src', $allow_remote, $value );
168	}
169
170	/**
171	* Prepare actor meta for emoji storage.
172	*
173	* Used for storing actor emoji data for comment author name rendering.
174	*
175	* @param array $actor The actor array containing potential emoji in tags.
176	*
177	* @return array Meta input array with emoji data, or empty array if no emoji.
178	*/
179	public static function prepare_actor_meta( $actor ) {
180	if ( empty( $actor['tag'] ) \|\| ! \is_array( $actor['tag'] ) ) {
181	return array();
182	}
183
184	$emoji_tags = \array_values(
185	\array_filter(
186	$actor['tag'],
187	function ( $tag ) {
188	return \is_array( $tag ) && isset( $tag['type'] ) && 'Emoji' === $tag['type'];
189	}
190	)
191	);
192
193	if ( empty( $emoji_tags ) ) {
194	return array();
195	}
196
197	return array(
198	'_activitypub_emoji' => \wp_json_encode( $emoji_tags ),
199	);
200	}
201
202	/**
203	* Replace emoji from stored JSON data.
204	*
205	* Used for comment author name replacement at display time.
206	*
207	* @param string $text The text to process.
208	* @param string $emoji_json JSON-encoded emoji tag data.
209	*
210	* @return string The processed text with emoji replacements.
211	*/
212	public static function replace_from_json( $text, $emoji_json ) {
213	$tags = \json_decode( $emoji_json, true );
214
215	if ( empty( $tags ) \|\| ! \is_array( $tags ) ) {
216	return $text;
217	}
218
219	foreach ( $tags as $tag ) {
220	if ( empty( $tag['name'] ) ) {
221	continue;
222	}
223
224	$url = object_to_uri( $tag['icon'] ?? null );
225	if ( empty( $url ) ) {
226	continue;
227	}
228
229	/**
230	* Filters a remote media URL for caching.
231	*
232	* @param string $url The remote media URL.
233	* @param string $context The context ('emoji').
234	* @param string\|null $entity_id The entity ID.
235	* @param array $options Additional options.
236	*/
237	$cached_url = \apply_filters(
238	'activitypub_remote_media_url',
239	$url,
240	'emoji',
241	null,
242	array( 'updated' => $tag['updated'] ?? null )
243	);
244
245	$name = \trim( $tag['name'], ':' );
246	$img = self::get_img_tag( $cached_url ?: $url, $name );
247
248	$text = \str_ireplace( $tag['name'], $img, $text );
249	}
250
251	return $text;
252	}
253
254	/**
255	* Replace emoji in text using a remote actor's stored emoji data.
256	*
257	* Used by Mailer class for actor name/summary in emails.
258	*
259	* @param string $text The text to process.
260	* @param string $actor_url The actor's URL to look up emoji data.
261	*
262	* @return string The processed text with emoji replacements.
263	*/
264	public static function replace_for_actor( $text, $actor_url ) {
265	$actor_post = Collection\Remote_Actors::get_by_uri( $actor_url );
266	if ( ! $actor_post \|\| \is_wp_error( $actor_post ) ) {
267	return $text;
268	}
269
270	$emoji_data = \get_post_meta( $actor_post->ID, '_activitypub_emoji', true );
271	if ( empty( $emoji_data ) ) {
272	return $text;
273	}
274
275	return self::replace_from_json( $text, $emoji_data );
276	}
277	}
278