activitypub / includes / class-embed.php

class-embed.php in ActivityPub 5.7.0, at includes/class-embed.php

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1	<?php
2	/**
3	* ActivityPub Embed Handler.
4	*
5	* @package Activitypub
6	*/
7
8	namespace Activitypub;
9
10	use WP_REST_Response;
11
12	/**
13	* Class to handle embedding ActivityPub content
14	*/
15	class Embed {
16
17	/**
18	* Initialize the embed handler
19	*/
20	public static function init() {
21	add_filter( 'pre_oembed_result', array( __CLASS__, 'maybe_use_activitypub_embed' ), 10, 3 );
22	add_filter( 'oembed_dataparse', array( __CLASS__, 'handle_filtered_oembed_result' ), 11, 3 );
23	}
24
25	/**
26	* Check if a real oEmbed result exists for the given URL.
27	*
28	* @param string $url The URL to check.
29	* @param array $args Additional arguments passed to wp_oembed_get().
30	* @return bool True if a real oEmbed result exists, false otherwise.
31	*/
32	public static function has_real_oembed( $url, $args = array() ) {
33	// Temporarily remove our filter to avoid infinite loops.
34	remove_filter( 'pre_oembed_result', array( __CLASS__, 'maybe_use_activitypub_embed' ), 10, 3 );
35
36	// Try to get a "real" oEmbed result. If found, it'll be cached to avoid unnecessary HTTP requests in `wp_oembed_get`.
37	$oembed_result = wp_oembed_get( $url, $args );
38
39	// Add our filter back.
40	add_filter( 'pre_oembed_result', array( __CLASS__, 'maybe_use_activitypub_embed' ), 10, 3 );
41
42	return false !== $oembed_result;
43	}
44
45	/**
46	* Filter the oembed result to handle ActivityPub content when no oEmbed is found.
47	* Implementation is a bit weird because there's no way to filter on a false result, we have to use `pre_oembed_result`.
48	*
49	* @param null\|string $result The UNSANITIZED (and potentially unsafe) HTML that should be used to embed.
50	* @param string $url The URL to the content that should be attempted to be embedded.
51	* @param array $args Additional arguments passed to wp_oembed_get().
52	* @return null\|string Return null to allow normal oEmbed processing, or string for ActivityPub embed.
53	*/
54	public static function maybe_use_activitypub_embed( $result, $url, $args ) {
55	// If we already have a result, return it.
56	if ( null !== $result ) {
57	return $result;
58	}
59
60	// If we found a real oEmbed, return null to allow normal processing.
61	if ( self::has_real_oembed( $url, $args ) ) {
62	return null;
63	}
64
65	// No oEmbed found, try to get ActivityPub representation.
66	$html = get_embed_html( $url );
67
68	// If we couldn't get an ActivityPub embed either, return null to allow normal processing.
69	if ( ! $html ) {
70	return null;
71	}
72
73	// Return the ActivityPub embed HTML.
74	return $html;
75	}
76
77	/**
78	* Handle cases where WordPress has filtered out the oEmbed result for security reasons,
79	* but we can provide a safe ActivityPub-specific markup.
80	*
81	* This runs after wp_filter_oembed_result has potentially nullified the result.
82	*
83	* @param string\|false $html The returned oEmbed HTML.
84	* @param object $data A data object result from an oEmbed provider.
85	* @param string $url The URL of the content to be embedded.
86	* @return string\|false The filtered oEmbed HTML or our ActivityPub embed.
87	*/
88	public static function handle_filtered_oembed_result( $html, $data, $url ) {
89	// If we already have valid HTML, return it.
90	if ( $html ) {
91	return $html;
92	}
93
94	// If this isn't a rich or video type, we can't help.
95	if ( ! isset( $data->type ) \|\| ! in_array( $data->type, array( 'rich', 'video' ), true ) ) {
96	return $html;
97	}
98
99	// If there's no HTML in the data, we can't help.
100	if ( empty( $data->html ) \|\| ! is_string( $data->html ) ) {
101	return $html;
102	}
103
104	// Try to get ActivityPub representation.
105	$activitypub_html = get_embed_html( $url );
106	if ( ! $activitypub_html ) {
107	return $html;
108	}
109
110	// Return our safer ActivityPub embed HTML.
111	return $activitypub_html;
112	}
113	}
114