summaryrefslogtreecommitdiffstats
path: root/wp-includes/class-wp-embed.php
blob: 6b9eaa25db7bc530b666ef8e7146a9936f9a82a0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
<?php
/**
 * API for easily embedding rich media such as videos and images into content.
 *
 * @package WordPress
 * @subpackage Embed
 * @since 2.9.0
 */
#[AllowDynamicProperties]
class WP_Embed {
	public $handlers = array();
	public $post_ID;
	public $usecache      = true;
	public $linkifunknown = true;
	public $last_attr     = array();
	public $last_url      = '';

	/**
	 * When a URL cannot be embedded, return false instead of returning a link
	 * or the URL.
	 *
	 * Bypasses the {@see 'embed_maybe_make_link'} filter.
	 *
	 * @var bool
	 */
	public $return_false_on_fail = false;

	/**
	 * Constructor
	 */
	public function __construct() {
		// Hack to get the [embed] shortcode to run before wpautop().
		add_filter( 'the_content', array( $this, 'run_shortcode' ), 8 );
		add_filter( 'widget_text_content', array( $this, 'run_shortcode' ), 8 );
		add_filter( 'widget_block_content', array( $this, 'run_shortcode' ), 8 );

		// Shortcode placeholder for strip_shortcodes().
		add_shortcode( 'embed', '__return_false' );

		// Attempts to embed all URLs in a post.
		add_filter( 'the_content', array( $this, 'autoembed' ), 8 );
		add_filter( 'widget_text_content', array( $this, 'autoembed' ), 8 );
		add_filter( 'widget_block_content', array( $this, 'autoembed' ), 8 );

		// After a post is saved, cache oEmbed items via Ajax.
		add_action( 'edit_form_advanced', array( $this, 'maybe_run_ajax_cache' ) );
		add_action( 'edit_page_form', array( $this, 'maybe_run_ajax_cache' ) );
	}

	/**
	 * Processes the [embed] shortcode.
	 *
	 * Since the [embed] shortcode needs to be run earlier than other shortcodes,
	 * this function removes all existing shortcodes, registers the [embed] shortcode,
	 * calls do_shortcode(), and then re-registers the old shortcodes.
	 *
	 * @global array $shortcode_tags
	 *
	 * @param string $content Content to parse.
	 * @return string Content with shortcode parsed.
	 */
	public function run_shortcode( $content ) {
		global $shortcode_tags;

		// Back up current registered shortcodes and clear them all out.
		$orig_shortcode_tags = $shortcode_tags;
		remove_all_shortcodes();

		add_shortcode( 'embed', array( $this, 'shortcode' ) );

		// Do the shortcode (only the [embed] one is registered).
		$content = do_shortcode( $content, true );

		// Put the original shortcodes back.
		$shortcode_tags = $orig_shortcode_tags;

		return $content;
	}

	/**
	 * If a post/page was saved, then output JavaScript to make
	 * an Ajax request that will call WP_Embed::cache_oembed().
	 */
	public function maybe_run_ajax_cache() {
		$post = get_post();

		if ( ! $post || empty( $_GET['message'] ) ) {
			return;
		}
		?>
<script type="text/javascript">
	jQuery( function($) {
		$.get("<?php echo esc_url( admin_url( 'admin-ajax.php', 'relative' ) ) . '?action=oembed-cache&post=' . $post->ID; ?>");
	} );
</script>
		<?php
	}

	/**
	 * Registers an embed handler.
	 *
	 * Do not use this function directly, use wp_embed_register_handler() instead.
	 *
	 * This function should probably also only be used for sites that do not support oEmbed.
	 *
	 * @param string   $id       An internal ID/name for the handler. Needs to be unique.
	 * @param string   $regex    The regex that will be used to see if this handler should be used for a URL.
	 * @param callable $callback The callback function that will be called if the regex is matched.
	 * @param int      $priority Optional. Used to specify the order in which the registered handlers will be tested.
	 *                           Lower numbers correspond with earlier testing, and handlers with the same priority are
	 *                           tested in the order in which they were added to the action. Default 10.
	 */
	public function register_handler( $id, $regex, $callback, $priority = 10 ) {
		$this->handlers[ $priority ][ $id ] = array(
			'regex'    => $regex,
			'callback' => $callback,
		);
	}

	/**
	 * Unregisters a previously-registered embed handler.
	 *
	 * Do not use this function directly, use wp_embed_unregister_handler() instead.
	 *
	 * @param string $id       The handler ID that should be removed.
	 * @param int    $priority Optional. The priority of the handler to be removed (default: 10).
	 */
	public function unregister_handler( $id, $priority = 10 ) {
		unset( $this->handlers[ $priority ][ $id ] );
	}

	/**
	 * Returns embed HTML for a given URL from embed handlers.
	 *
	 * Attempts to convert a URL into embed HTML by checking the URL
	 * against the regex of the registered embed handlers.
	 *
	 * @since 5.5.0
	 *
	 * @param array  $attr {
	 *     Shortcode attributes. Optional.
	 *
	 *     @type int $width  Width of the embed in pixels.
	 *     @type int $height Height of the embed in pixels.
	 * }
	 * @param string $url The URL attempting to be embedded.
	 * @return string|false The embed HTML on success, false otherwise.
	 */
	public function get_embed_handler_html( $attr, $url ) {
		$rawattr = $attr;
		$attr    = wp_parse_args( $attr, wp_embed_defaults( $url ) );

		ksort( $this->handlers );
		foreach ( $this->handlers as $priority => $handlers ) {
			foreach ( $handlers as $id => $handler ) {
				if ( preg_match( $handler['regex'], $url, $matches ) && is_callable( $handler['callback'] ) ) {
					$return = call_user_func( $handler['callback'], $matches, $attr, $url, $rawattr );
					if ( false !== $return ) {
						/**
						 * Filters the returned embed HTML.
						 *
						 * @since 2.9.0
						 *
						 * @see WP_Embed::shortcode()
						 *
						 * @param string|false $return The HTML result of the shortcode, or false on failure.
						 * @param string       $url    The embed URL.
						 * @param array        $attr   An array of shortcode attributes.
						 */
						return apply_filters( 'embed_handler_html', $return, $url, $attr );
					}
				}
			}
		}

		return false;
	}

	/**
	 * The do_shortcode() callback function.
	 *
	 * Attempts to convert a URL into embed HTML. Starts by checking the URL against the regex of
	 * the registered embed handlers. If none of the regex matches and it's enabled, then the URL
	 * will be given to the WP_oEmbed class.
	 *
	 * @param array  $attr {
	 *     Shortcode attributes. Optional.
	 *
	 *     @type int $width  Width of the embed in pixels.
	 *     @type int $height Height of the embed in pixels.
	 * }
	 * @param string $url The URL attempting to be embedded.
	 * @return string|false The embed HTML on success, otherwise the original URL.
	 *                      `->maybe_make_link()` can return false on failure.
	 */
	public function shortcode( $attr, $url = '' ) {
		$post = get_post();

		if ( empty( $url ) && ! empty( $attr['src'] ) ) {
			$url = $attr['src'];
		}

		$this->last_url = $url;

		if ( empty( $url ) ) {
			$this->last_attr = $attr;
			return '';
		}

		$rawattr = $attr;
		$attr    = wp_parse_args( $attr, wp_embed_defaults( $url ) );

		$this->last_attr = $attr;

		/*
		 * KSES converts & into &amp; and we need to undo this.
		 * See https://core.trac.wordpress.org/ticket/11311
		 */
		$url = str_replace( '&amp;', '&', $url );

		// Look for known internal handlers.
		$embed_handler_html = $this->get_embed_handler_html( $rawattr, $url );
		if ( false !== $embed_handler_html ) {
			return $embed_handler_html;
		}

		$post_id = ( ! empty( $post->ID ) ) ? $post->ID : null;

		// Potentially set by WP_Embed::cache_oembed().
		if ( ! empty( $this->post_ID ) ) {
			$post_id = $this->post_ID;
		}

		// Check for a cached result (stored as custom post or in the post meta).
		$key_suffix    = md5( $url . serialize( $attr ) );
		$cachekey      = '_oembed_' . $key_suffix;
		$cachekey_time = '_oembed_time_' . $key_suffix;

		/**
		 * Filters the oEmbed TTL value (time to live).
		 *
		 * @since 4.0.0
		 *
		 * @param int    $time    Time to live (in seconds).
		 * @param string $url     The attempted embed URL.
		 * @param array  $attr    An array of shortcode attributes.
		 * @param int    $post_id Post ID.
		 */
		$ttl = apply_filters( 'oembed_ttl', DAY_IN_SECONDS, $url, $attr, $post_id );

		$cache      = '';
		$cache_time = 0;

		$cached_post_id = $this->find_oembed_post_id( $key_suffix );

		if ( $post_id ) {
			$cache      = get_post_meta( $post_id, $cachekey, true );
			$cache_time = get_post_meta( $post_id, $cachekey_time, true );

			if ( ! $cache_time ) {
				$cache_time = 0;
			}
		} elseif ( $cached_post_id ) {
			$cached_post = get_post( $cached_post_id );

			$cache      = $cached_post->post_content;
			$cache_time = strtotime( $cached_post->post_modified_gmt );
		}

		$cached_recently = ( time() - $cache_time ) < $ttl;

		if ( $this->usecache || $cached_recently ) {
			// Failures are cached. Serve one if we're using the cache.
			if ( '{{unknown}}' === $cache ) {
				return $this->maybe_make_link( $url );
			}

			if ( ! empty( $cache ) ) {
				/**
				 * Filters the cached oEmbed HTML.
				 *
				 * @since 2.9.0
				 *
				 * @see WP_Embed::shortcode()
				 *
				 * @param string|false $cache   The cached HTML result, stored in post meta.
				 * @param string       $url     The attempted embed URL.
				 * @param array        $attr    An array of shortcode attributes.
				 * @param int          $post_id Post ID.
				 */
				return apply_filters( 'embed_oembed_html', $cache, $url, $attr, $post_id );
			}
		}

		/**
		 * Filters whether to inspect the given URL for discoverable link tags.
		 *
		 * @since 2.9.0
		 * @since 4.4.0 The default value changed to true.
		 *
		 * @see WP_oEmbed::discover()
		 *
		 * @param bool $enable Whether to enable `<link>` tag discovery. Default true.
		 */
		$attr['discover'] = apply_filters( 'embed_oembed_discover', true );

		// Use oEmbed to get the HTML.
		$html = wp_oembed_get( $url, $attr );

		if ( $post_id ) {
			if ( $html ) {
				update_post_meta( $post_id, $cachekey, $html );
				update_post_meta( $post_id, $cachekey_time, time() );
			} elseif ( ! $cache ) {
				update_post_meta( $post_id, $cachekey, '{{unknown}}' );
			}
		} else {
			$has_kses = false !== has_filter( 'content_save_pre', 'wp_filter_post_kses' );

			if ( $has_kses ) {
				// Prevent KSES from corrupting JSON in post_content.
				kses_remove_filters();
			}

			$insert_post_args = array(
				'post_name'   => $key_suffix,
				'post_status' => 'publish',
				'post_type'   => 'oembed_cache',
			);

			if ( $html ) {
				if ( $cached_post_id ) {
					wp_update_post(
						wp_slash(
							array(
								'ID'           => $cached_post_id,
								'post_content' => $html,
							)
						)
					);
				} else {
					wp_insert_post(
						wp_slash(
							array_merge(
								$insert_post_args,
								array(
									'post_content' => $html,
								)
							)
						)
					);
				}
			} elseif ( ! $cache ) {
				wp_insert_post(
					wp_slash(
						array_merge(
							$insert_post_args,
							array(
								'post_content' => '{{unknown}}',
							)
						)
					)
				);
			}

			if ( $has_kses ) {
				kses_init_filters();
			}
		}

		// If there was a result, return it.
		if ( $html ) {
			/** This filter is documented in wp-includes/class-wp-embed.php */
			return apply_filters( 'embed_oembed_html', $html, $url, $attr, $post_id );
		}

		// Still unknown.
		return $this->maybe_make_link( $url );
	}

	/**
	 * Deletes all oEmbed caches. Unused by core as of 4.0.0.
	 *
	 * @param int $post_id Post ID to delete the caches for.
	 */
	public function delete_oembed_caches( $post_id ) {
		$post_metas = get_post_custom_keys( $post_id );
		if ( empty( $post_metas ) ) {
			return;
		}

		foreach ( $post_metas as $post_meta_key ) {
			if ( str_starts_with( $post_meta_key, '_oembed_' ) ) {
				delete_post_meta( $post_id, $post_meta_key );
			}
		}
	}

	/**
	 * Triggers a caching of all oEmbed results.
	 *
	 * @param int $post_id Post ID to do the caching for.
	 */
	public function cache_oembed( $post_id ) {
		$post = get_post( $post_id );

		$post_types = get_post_types( array( 'show_ui' => true ) );

		/**
		 * Filters the array of post types to cache oEmbed results for.
		 *
		 * @since 2.9.0
		 *
		 * @param string[] $post_types Array of post type names to cache oEmbed results for. Defaults to post types with `show_ui` set to true.
		 */
		$cache_oembed_types = apply_filters( 'embed_cache_oembed_types', $post_types );

		if ( empty( $post->ID ) || ! in_array( $post->post_type, $cache_oembed_types, true ) ) {
			return;
		}

		// Trigger a caching.
		if ( ! empty( $post->post_content ) ) {
			$this->post_ID  = $post->ID;
			$this->usecache = false;

			$content = $this->run_shortcode( $post->post_content );
			$this->autoembed( $content );

			$this->usecache = true;
		}
	}

	/**
	 * Passes any unlinked URLs that are on their own line to WP_Embed::shortcode() for potential embedding.
	 *
	 * @see WP_Embed::autoembed_callback()
	 *
	 * @param string $content The content to be searched.
	 * @return string Potentially modified $content.
	 */
	public function autoembed( $content ) {
		// Replace line breaks from all HTML elements with placeholders.
		$content = wp_replace_in_html_tags( $content, array( "\n" => '<!-- wp-line-break -->' ) );

		if ( preg_match( '#(^|\s|>)https?://#i', $content ) ) {
			// Find URLs on their own line.
			$content = preg_replace_callback( '|^(\s*)(https?://[^\s<>"]+)(\s*)$|im', array( $this, 'autoembed_callback' ), $content );
			// Find URLs in their own paragraph.
			$content = preg_replace_callback( '|(<p(?: [^>]*)?>\s*)(https?://[^\s<>"]+)(\s*<\/p>)|i', array( $this, 'autoembed_callback' ), $content );
		}

		// Put the line breaks back.
		return str_replace( '<!-- wp-line-break -->', "\n", $content );
	}

	/**
	 * Callback function for WP_Embed::autoembed().
	 *
	 * @param array $matches A regex match array.
	 * @return string The embed HTML on success, otherwise the original URL.
	 */
	public function autoembed_callback( $matches ) {
		$oldval              = $this->linkifunknown;
		$this->linkifunknown = false;
		$return              = $this->shortcode( array(), $matches[2] );
		$this->linkifunknown = $oldval;

		return $matches[1] . $return . $matches[3];
	}

	/**
	 * Conditionally makes a hyperlink based on an internal class variable.
	 *
	 * @param string $url URL to potentially be linked.
	 * @return string|false Linked URL or the original URL. False if 'return_false_on_fail' is true.
	 */
	public function maybe_make_link( $url ) {
		if ( $this->return_false_on_fail ) {
			return false;
		}

		$output = ( $this->linkifunknown ) ? '<a href="' . esc_url( $url ) . '">' . esc_html( $url ) . '</a>' : $url;

		/**
		 * Filters the returned, maybe-linked embed URL.
		 *
		 * @since 2.9.0
		 *
		 * @param string $output The linked or original URL.
		 * @param string $url    The original URL.
		 */
		return apply_filters( 'embed_maybe_make_link', $output, $url );
	}

	/**
	 * Finds the oEmbed cache post ID for a given cache key.
	 *
	 * @since 4.9.0
	 *
	 * @param string $cache_key oEmbed cache key.
	 * @return int|null Post ID on success, null on failure.
	 */
	public function find_oembed_post_id( $cache_key ) {
		$cache_group    = 'oembed_cache_post';
		$oembed_post_id = wp_cache_get( $cache_key, $cache_group );

		if ( $oembed_post_id && 'oembed_cache' === get_post_type( $oembed_post_id ) ) {
			return $oembed_post_id;
		}

		$oembed_post_query = new WP_Query(
			array(
				'post_type'              => 'oembed_cache',
				'post_status'            => 'publish',
				'name'                   => $cache_key,
				'posts_per_page'         => 1,
				'no_found_rows'          => true,
				'cache_results'          => true,
				'update_post_meta_cache' => false,
				'update_post_term_cache' => false,
				'lazy_load_term_meta'    => false,
			)
		);

		if ( ! empty( $oembed_post_query->posts ) ) {
			// Note: 'fields' => 'ids' is not being used in order to cache the post object as it will be needed.
			$oembed_post_id = $oembed_post_query->posts[0]->ID;
			wp_cache_set( $cache_key, $oembed_post_id, $cache_group );

			return $oembed_post_id;
		}

		return null;
	}
}