1<?php
2/**
3 * WordPress Link Template Functions
4 *
5 * @package WordPress
6 * @subpackage Template
7 */
8
9/**
10 * Displays the permalink for the current post.
11 *
12 * @since 1.2.0
13 * @since 4.4.0 Added the `$post` parameter.
14 *
15 * @param int|WP_Post $post Optional. Post ID or post object. Default is the global `$post`.
16 */
17function the_permalink( $post = 0 ) {
18	/**
19	 * Filters the display of the permalink for the current post.
20	 *
21	 * @since 1.5.0
22	 * @since 4.4.0 Added the `$post` parameter.
23	 *
24	 * @param string      $permalink The permalink for the current post.
25	 * @param int|WP_Post $post      Post ID, WP_Post object, or 0. Default 0.
26	 */
27	echo esc_url( apply_filters( 'the_permalink', get_permalink( $post ), $post ) );
28}
29
30/**
31 * Retrieves a trailing-slashed string if the site is set for adding trailing slashes.
32 *
33 * Conditionally adds a trailing slash if the permalink structure has a trailing
34 * slash, strips the trailing slash if not. The string is passed through the
35 * {@see 'user_trailingslashit'} filter. Will remove trailing slash from string, if
36 * site is not set to have them.
37 *
38 * @since 2.2.0
39 *
40 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
41 *
42 * @param string $string      URL with or without a trailing slash.
43 * @param string $type_of_url Optional. The type of URL being considered (e.g. single, category, etc)
44 *                            for use in the filter. Default empty string.
45 * @return string The URL with the trailing slash appended or stripped.
46 */
47function user_trailingslashit( $string, $type_of_url = '' ) {
48	global $wp_rewrite;
49	if ( $wp_rewrite->use_trailing_slashes ) {
50		$string = trailingslashit( $string );
51	} else {
52		$string = untrailingslashit( $string );
53	}
54
55	/**
56	 * Filters the trailing-slashed string, depending on whether the site is set to use trailing slashes.
57	 *
58	 * @since 2.2.0
59	 *
60	 * @param string $string      URL with or without a trailing slash.
61	 * @param string $type_of_url The type of URL being considered. Accepts 'single', 'single_trackback',
62	 *                            'single_feed', 'single_paged', 'commentpaged', 'paged', 'home', 'feed',
63	 *                            'category', 'page', 'year', 'month', 'day', 'post_type_archive'.
64	 */
65	return apply_filters( 'user_trailingslashit', $string, $type_of_url );
66}
67
68/**
69 * Displays the permalink anchor for the current post.
70 *
71 * The permalink mode title will use the post title for the 'a' element 'id'
72 * attribute. The id mode uses 'post-' with the post ID for the 'id' attribute.
73 *
74 * @since 0.71
75 *
76 * @param string $mode Optional. Permalink mode. Accepts 'title' or 'id'. Default 'id'.
77 */
78function permalink_anchor( $mode = 'id' ) {
79	$post = get_post();
80	switch ( strtolower( $mode ) ) {
81		case 'title':
82			$title = sanitize_title( $post->post_title ) . '-' . $post->ID;
83			echo '<a id="' . $title . '"></a>';
84			break;
85		case 'id':
86		default:
87			echo '<a id="post-' . $post->ID . '"></a>';
88			break;
89	}
90}
91
92/**
93 * Determine whether post should always use a plain permalink structure.
94 *
95 * @since 5.7.0
96 *
97 * @param WP_Post|int|null $post   Optional. Post ID or post object. Defaults to global $post.
98 * @param bool|null        $sample Optional. Whether to force consideration based on sample links.
99 *                                 If omitted, a sample link is generated if a post object is passed
100 *                                 with the filter property set to 'sample'.
101 * @return bool Whether to use a plain permalink structure.
102 */
103function wp_force_plain_post_permalink( $post = null, $sample = null ) {
104	if (
105		null === $sample &&
106		is_object( $post ) &&
107		isset( $post->filter ) &&
108		'sample' === $post->filter
109	) {
110		$sample = true;
111	} else {
112		$post   = get_post( $post );
113		$sample = null !== $sample ? $sample : false;
114	}
115
116	if ( ! $post ) {
117		return true;
118	}
119
120	$post_status_obj = get_post_status_object( get_post_status( $post ) );
121	$post_type_obj   = get_post_type_object( get_post_type( $post ) );
122
123	if ( ! $post_status_obj || ! $post_type_obj ) {
124		return true;
125	}
126
127	if (
128		// Publicly viewable links never have plain permalinks.
129		is_post_status_viewable( $post_status_obj ) ||
130		(
131			// Private posts don't have plain permalinks if the user can read them.
132			$post_status_obj->private &&
133			current_user_can( 'read_post', $post->ID )
134		) ||
135		// Protected posts don't have plain links if getting a sample URL.
136		( $post_status_obj->protected && $sample )
137	) {
138		return false;
139	}
140
141	return true;
142}
143
144/**
145 * Retrieves the full permalink for the current post or post ID.
146 *
147 * This function is an alias for get_permalink().
148 *
149 * @since 3.9.0
150 *
151 * @see get_permalink()
152 *
153 * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.
154 * @param bool        $leavename Optional. Whether to keep post name or page name. Default false.
155 * @return string|false The permalink URL or false if post does not exist.
156 */
157function get_the_permalink( $post = 0, $leavename = false ) {
158	return get_permalink( $post, $leavename );
159}
160
161/**
162 * Retrieves the full permalink for the current post or post ID.
163 *
164 * @since 1.0.0
165 *
166 * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.
167 * @param bool        $leavename Optional. Whether to keep post name or page name. Default false.
168 * @return string|false The permalink URL or false if post does not exist.
169 */
170function get_permalink( $post = 0, $leavename = false ) {
171	$rewritecode = array(
172		'%year%',
173		'%monthnum%',
174		'%day%',
175		'%hour%',
176		'%minute%',
177		'%second%',
178		$leavename ? '' : '%postname%',
179		'%post_id%',
180		'%category%',
181		'%author%',
182		$leavename ? '' : '%pagename%',
183	);
184
185	if ( is_object( $post ) && isset( $post->filter ) && 'sample' === $post->filter ) {
186		$sample = true;
187	} else {
188		$post   = get_post( $post );
189		$sample = false;
190	}
191
192	if ( empty( $post->ID ) ) {
193		return false;
194	}
195
196	if ( 'page' === $post->post_type ) {
197		return get_page_link( $post, $leavename, $sample );
198	} elseif ( 'attachment' === $post->post_type ) {
199		return get_attachment_link( $post, $leavename );
200	} elseif ( in_array( $post->post_type, get_post_types( array( '_builtin' => false ) ), true ) ) {
201		return get_post_permalink( $post, $leavename, $sample );
202	}
203
204	$permalink = get_option( 'permalink_structure' );
205
206	/**
207	 * Filters the permalink structure for a post before token replacement occurs.
208	 *
209	 * Only applies to posts with post_type of 'post'.
210	 *
211	 * @since 3.0.0
212	 *
213	 * @param string  $permalink The site's permalink structure.
214	 * @param WP_Post $post      The post in question.
215	 * @param bool    $leavename Whether to keep the post name.
216	 */
217	$permalink = apply_filters( 'pre_post_link', $permalink, $post, $leavename );
218
219	if (
220		$permalink &&
221		! wp_force_plain_post_permalink( $post )
222	) {
223
224		$category = '';
225		if ( strpos( $permalink, '%category%' ) !== false ) {
226			$cats = get_the_category( $post->ID );
227			if ( $cats ) {
228				$cats = wp_list_sort(
229					$cats,
230					array(
231						'term_id' => 'ASC',
232					)
233				);
234
235				/**
236				 * Filters the category that gets used in the %category% permalink token.
237				 *
238				 * @since 3.5.0
239				 *
240				 * @param WP_Term  $cat  The category to use in the permalink.
241				 * @param array    $cats Array of all categories (WP_Term objects) associated with the post.
242				 * @param WP_Post  $post The post in question.
243				 */
244				$category_object = apply_filters( 'post_link_category', $cats[0], $cats, $post );
245
246				$category_object = get_term( $category_object, 'category' );
247				$category        = $category_object->slug;
248				if ( $category_object->parent ) {
249					$category = get_category_parents( $category_object->parent, false, '/', true ) . $category;
250				}
251			}
252			// Show default category in permalinks,
253			// without having to assign it explicitly.
254			if ( empty( $category ) ) {
255				$default_category = get_term( get_option( 'default_category' ), 'category' );
256				if ( $default_category && ! is_wp_error( $default_category ) ) {
257					$category = $default_category->slug;
258				}
259			}
260		}
261
262		$author = '';
263		if ( strpos( $permalink, '%author%' ) !== false ) {
264			$authordata = get_userdata( $post->post_author );
265			$author     = $authordata->user_nicename;
266		}
267
268		// This is not an API call because the permalink is based on the stored post_date value,
269		// which should be parsed as local time regardless of the default PHP timezone.
270		$date = explode( ' ', str_replace( array( '-', ':' ), ' ', $post->post_date ) );
271
272		$rewritereplace = array(
273			$date[0],
274			$date[1],
275			$date[2],
276			$date[3],
277			$date[4],
278			$date[5],
279			$post->post_name,
280			$post->ID,
281			$category,
282			$author,
283			$post->post_name,
284		);
285
286		$permalink = home_url( str_replace( $rewritecode, $rewritereplace, $permalink ) );
287		$permalink = user_trailingslashit( $permalink, 'single' );
288
289	} else { // If they're not using the fancy permalink option.
290		$permalink = home_url( '?p=' . $post->ID );
291	}
292
293	/**
294	 * Filters the permalink for a post.
295	 *
296	 * Only applies to posts with post_type of 'post'.
297	 *
298	 * @since 1.5.0
299	 *
300	 * @param string  $permalink The post's permalink.
301	 * @param WP_Post $post      The post in question.
302	 * @param bool    $leavename Whether to keep the post name.
303	 */
304	return apply_filters( 'post_link', $permalink, $post, $leavename );
305}
306
307/**
308 * Retrieves the permalink for a post of a custom post type.
309 *
310 * @since 3.0.0
311 *
312 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
313 *
314 * @param int|WP_Post $id        Optional. Post ID or post object. Default is the global `$post`.
315 * @param bool        $leavename Optional. Whether to keep post name. Default false.
316 * @param bool        $sample    Optional. Is it a sample permalink. Default false.
317 * @return string|WP_Error The post permalink.
318 */
319function get_post_permalink( $id = 0, $leavename = false, $sample = false ) {
320	global $wp_rewrite;
321
322	$post = get_post( $id );
323
324	if ( is_wp_error( $post ) ) {
325		return $post;
326	}
327
328	$post_link = $wp_rewrite->get_extra_permastruct( $post->post_type );
329
330	$slug = $post->post_name;
331
332	$force_plain_link = wp_force_plain_post_permalink( $post );
333
334	$post_type = get_post_type_object( $post->post_type );
335
336	if ( $post_type->hierarchical ) {
337		$slug = get_page_uri( $post );
338	}
339
340	if ( ! empty( $post_link ) && ( ! $force_plain_link || $sample ) ) {
341		if ( ! $leavename ) {
342			$post_link = str_replace( "%$post->post_type%", $slug, $post_link );
343		}
344		$post_link = home_url( user_trailingslashit( $post_link ) );
345	} else {
346		if ( $post_type->query_var && ( isset( $post->post_status ) && ! $force_plain_link ) ) {
347			$post_link = add_query_arg( $post_type->query_var, $slug, '' );
348		} else {
349			$post_link = add_query_arg(
350				array(
351					'post_type' => $post->post_type,
352					'p'         => $post->ID,
353				),
354				''
355			);
356		}
357		$post_link = home_url( $post_link );
358	}
359
360	/**
361	 * Filters the permalink for a post of a custom post type.
362	 *
363	 * @since 3.0.0
364	 *
365	 * @param string  $post_link The post's permalink.
366	 * @param WP_Post $post      The post in question.
367	 * @param bool    $leavename Whether to keep the post name.
368	 * @param bool    $sample    Is it a sample permalink.
369	 */
370	return apply_filters( 'post_type_link', $post_link, $post, $leavename, $sample );
371}
372
373/**
374 * Retrieves the permalink for the current page or page ID.
375 *
376 * Respects page_on_front. Use this one.
377 *
378 * @since 1.5.0
379 *
380 * @param int|WP_Post $post      Optional. Post ID or object. Default uses the global `$post`.
381 * @param bool        $leavename Optional. Whether to keep the page name. Default false.
382 * @param bool        $sample    Optional. Whether it should be treated as a sample permalink.
383 *                               Default false.
384 * @return string The page permalink.
385 */
386function get_page_link( $post = false, $leavename = false, $sample = false ) {
387	$post = get_post( $post );
388
389	if ( 'page' === get_option( 'show_on_front' ) && get_option( 'page_on_front' ) == $post->ID ) {
390		$link = home_url( '/' );
391	} else {
392		$link = _get_page_link( $post, $leavename, $sample );
393	}
394
395	/**
396	 * Filters the permalink for a page.
397	 *
398	 * @since 1.5.0
399	 *
400	 * @param string $link    The page's permalink.
401	 * @param int    $post_id The ID of the page.
402	 * @param bool   $sample  Is it a sample permalink.
403	 */
404	return apply_filters( 'page_link', $link, $post->ID, $sample );
405}
406
407/**
408 * Retrieves the page permalink.
409 *
410 * Ignores page_on_front. Internal use only.
411 *
412 * @since 2.1.0
413 * @access private
414 *
415 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
416 *
417 * @param int|WP_Post $post      Optional. Post ID or object. Default uses the global `$post`.
418 * @param bool        $leavename Optional. Whether to keep the page name. Default false.
419 * @param bool        $sample    Optional. Whether it should be treated as a sample permalink.
420 *                               Default false.
421 * @return string The page permalink.
422 */
423function _get_page_link( $post = false, $leavename = false, $sample = false ) {
424	global $wp_rewrite;
425
426	$post = get_post( $post );
427
428	$force_plain_link = wp_force_plain_post_permalink( $post );
429
430	$link = $wp_rewrite->get_page_permastruct();
431
432	if ( ! empty( $link ) && ( ( isset( $post->post_status ) && ! $force_plain_link ) || $sample ) ) {
433		if ( ! $leavename ) {
434			$link = str_replace( '%pagename%', get_page_uri( $post ), $link );
435		}
436
437		$link = home_url( $link );
438		$link = user_trailingslashit( $link, 'page' );
439	} else {
440		$link = home_url( '?page_id=' . $post->ID );
441	}
442
443	/**
444	 * Filters the permalink for a non-page_on_front page.
445	 *
446	 * @since 2.1.0
447	 *
448	 * @param string $link    The page's permalink.
449	 * @param int    $post_id The ID of the page.
450	 */
451	return apply_filters( '_get_page_link', $link, $post->ID );
452}
453
454/**
455 * Retrieves the permalink for an attachment.
456 *
457 * This can be used in the WordPress Loop or outside of it.
458 *
459 * @since 2.0.0
460 *
461 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
462 *
463 * @param int|object $post      Optional. Post ID or object. Default uses the global `$post`.
464 * @param bool       $leavename Optional. Whether to keep the page name. Default false.
465 * @return string The attachment permalink.
466 */
467function get_attachment_link( $post = null, $leavename = false ) {
468	global $wp_rewrite;
469
470	$link = false;
471
472	$post             = get_post( $post );
473	$force_plain_link = wp_force_plain_post_permalink( $post );
474	$parent_id        = $post->post_parent;
475	$parent           = $parent_id ? get_post( $parent_id ) : false;
476	$parent_valid     = true; // Default for no parent.
477	if (
478		$parent_id &&
479		(
480			$post->post_parent === $post->ID ||
481			! $parent ||
482			! is_post_type_viewable( get_post_type( $parent ) )
483		)
484	) {
485		// Post is either its own parent or parent post unavailable.
486		$parent_valid = false;
487	}
488
489	if ( $force_plain_link || ! $parent_valid ) {
490		$link = false;
491	} elseif ( $wp_rewrite->using_permalinks() && $parent ) {
492		if ( 'page' === $parent->post_type ) {
493			$parentlink = _get_page_link( $post->post_parent ); // Ignores page_on_front.
494		} else {
495			$parentlink = get_permalink( $post->post_parent );
496		}
497
498		if ( is_numeric( $post->post_name ) || false !== strpos( get_option( 'permalink_structure' ), '%category%' ) ) {
499			$name = 'attachment/' . $post->post_name; // <permalink>/<int>/ is paged so we use the explicit attachment marker.
500		} else {
501			$name = $post->post_name;
502		}
503
504		if ( strpos( $parentlink, '?' ) === false ) {
505			$link = user_trailingslashit( trailingslashit( $parentlink ) . '%postname%' );
506		}
507
508		if ( ! $leavename ) {
509			$link = str_replace( '%postname%', $name, $link );
510		}
511	} elseif ( $wp_rewrite->using_permalinks() && ! $leavename ) {
512		$link = home_url( user_trailingslashit( $post->post_name ) );
513	}
514
515	if ( ! $link ) {
516		$link = home_url( '/?attachment_id=' . $post->ID );
517	}
518
519	/**
520	 * Filters the permalink for an attachment.
521	 *
522	 * @since 2.0.0
523	 * @since 5.6.0 Providing an empty string will now disable
524	 *              the view attachment page link on the media modal.
525	 *
526	 * @param string $link    The attachment's permalink.
527	 * @param int    $post_id Attachment ID.
528	 */
529	return apply_filters( 'attachment_link', $link, $post->ID );
530}
531
532/**
533 * Retrieves the permalink for the year archives.
534 *
535 * @since 1.5.0
536 *
537 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
538 *
539 * @param int|false $year Integer of year. False for current year.
540 * @return string The permalink for the specified year archive.
541 */
542function get_year_link( $year ) {
543	global $wp_rewrite;
544	if ( ! $year ) {
545		$year = current_time( 'Y' );
546	}
547	$yearlink = $wp_rewrite->get_year_permastruct();
548	if ( ! empty( $yearlink ) ) {
549		$yearlink = str_replace( '%year%', $year, $yearlink );
550		$yearlink = home_url( user_trailingslashit( $yearlink, 'year' ) );
551	} else {
552		$yearlink = home_url( '?m=' . $year );
553	}
554
555	/**
556	 * Filters the year archive permalink.
557	 *
558	 * @since 1.5.0
559	 *
560	 * @param string $yearlink Permalink for the year archive.
561	 * @param int    $year     Year for the archive.
562	 */
563	return apply_filters( 'year_link', $yearlink, $year );
564}
565
566/**
567 * Retrieves the permalink for the month archives with year.
568 *
569 * @since 1.0.0
570 *
571 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
572 *
573 * @param int|false $year  Integer of year. False for current year.
574 * @param int|false $month Integer of month. False for current month.
575 * @return string The permalink for the specified month and year archive.
576 */
577function get_month_link( $year, $month ) {
578	global $wp_rewrite;
579	if ( ! $year ) {
580		$year = current_time( 'Y' );
581	}
582	if ( ! $month ) {
583		$month = current_time( 'm' );
584	}
585	$monthlink = $wp_rewrite->get_month_permastruct();
586	if ( ! empty( $monthlink ) ) {
587		$monthlink = str_replace( '%year%', $year, $monthlink );
588		$monthlink = str_replace( '%monthnum%', zeroise( (int) $month, 2 ), $monthlink );
589		$monthlink = home_url( user_trailingslashit( $monthlink, 'month' ) );
590	} else {
591		$monthlink = home_url( '?m=' . $year . zeroise( $month, 2 ) );
592	}
593
594	/**
595	 * Filters the month archive permalink.
596	 *
597	 * @since 1.5.0
598	 *
599	 * @param string $monthlink Permalink for the month archive.
600	 * @param int    $year      Year for the archive.
601	 * @param int    $month     The month for the archive.
602	 */
603	return apply_filters( 'month_link', $monthlink, $year, $month );
604}
605
606/**
607 * Retrieves the permalink for the day archives with year and month.
608 *
609 * @since 1.0.0
610 *
611 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
612 *
613 * @param int|false $year  Integer of year. False for current year.
614 * @param int|false $month Integer of month. False for current month.
615 * @param int|false $day   Integer of day. False for current day.
616 * @return string The permalink for the specified day, month, and year archive.
617 */
618function get_day_link( $year, $month, $day ) {
619	global $wp_rewrite;
620	if ( ! $year ) {
621		$year = current_time( 'Y' );
622	}
623	if ( ! $month ) {
624		$month = current_time( 'm' );
625	}
626	if ( ! $day ) {
627		$day = current_time( 'j' );
628	}
629
630	$daylink = $wp_rewrite->get_day_permastruct();
631	if ( ! empty( $daylink ) ) {
632		$daylink = str_replace( '%year%', $year, $daylink );
633		$daylink = str_replace( '%monthnum%', zeroise( (int) $month, 2 ), $daylink );
634		$daylink = str_replace( '%day%', zeroise( (int) $day, 2 ), $daylink );
635		$daylink = home_url( user_trailingslashit( $daylink, 'day' ) );
636	} else {
637		$daylink = home_url( '?m=' . $year . zeroise( $month, 2 ) . zeroise( $day, 2 ) );
638	}
639
640	/**
641	 * Filters the day archive permalink.
642	 *
643	 * @since 1.5.0
644	 *
645	 * @param string $daylink Permalink for the day archive.
646	 * @param int    $year    Year for the archive.
647	 * @param int    $month   Month for the archive.
648	 * @param int    $day     The day for the archive.
649	 */
650	return apply_filters( 'day_link', $daylink, $year, $month, $day );
651}
652
653/**
654 * Displays the permalink for the feed type.
655 *
656 * @since 3.0.0
657 *
658 * @param string $anchor The link's anchor text.
659 * @param string $feed   Optional. Feed type. Possible values include 'rss2', 'atom'.
660 *                       Default is the value of get_default_feed().
661 */
662function the_feed_link( $anchor, $feed = '' ) {
663	$link = '<a href="' . esc_url( get_feed_link( $feed ) ) . '">' . $anchor . '</a>';
664
665	/**
666	 * Filters the feed link anchor tag.
667	 *
668	 * @since 3.0.0
669	 *
670	 * @param string $link The complete anchor tag for a feed link.
671	 * @param string $feed The feed type. Possible values include 'rss2', 'atom',
672	 *                     or an empty string for the default feed type.
673	 */
674	echo apply_filters( 'the_feed_link', $link, $feed );
675}
676
677/**
678 * Retrieves the permalink for the feed type.
679 *
680 * @since 1.5.0
681 *
682 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
683 *
684 * @param string $feed Optional. Feed type. Possible values include 'rss2', 'atom'.
685 *                     Default is the value of get_default_feed().
686 * @return string The feed permalink.
687 */
688function get_feed_link( $feed = '' ) {
689	global $wp_rewrite;
690
691	$permalink = $wp_rewrite->get_feed_permastruct();
692
693	if ( $permalink ) {
694		if ( false !== strpos( $feed, 'comments_' ) ) {
695			$feed      = str_replace( 'comments_', '', $feed );
696			$permalink = $wp_rewrite->get_comment_feed_permastruct();
697		}
698
699		if ( get_default_feed() == $feed ) {
700			$feed = '';
701		}
702
703		$permalink = str_replace( '%feed%', $feed, $permalink );
704		$permalink = preg_replace( '#/+#', '/', "/$permalink" );
705		$output    = home_url( user_trailingslashit( $permalink, 'feed' ) );
706	} else {
707		if ( empty( $feed ) ) {
708			$feed = get_default_feed();
709		}
710
711		if ( false !== strpos( $feed, 'comments_' ) ) {
712			$feed = str_replace( 'comments_', 'comments-', $feed );
713		}
714
715		$output = home_url( "?feed={$feed}" );
716	}
717
718	/**
719	 * Filters the feed type permalink.
720	 *
721	 * @since 1.5.0
722	 *
723	 * @param string $output The feed permalink.
724	 * @param string $feed   The feed type. Possible values include 'rss2', 'atom',
725	 *                       or an empty string for the default feed type.
726	 */
727	return apply_filters( 'feed_link', $output, $feed );
728}
729
730/**
731 * Retrieves the permalink for the post comments feed.
732 *
733 * @since 2.2.0
734 *
735 * @param int    $post_id Optional. Post ID. Default is the ID of the global `$post`.
736 * @param string $feed    Optional. Feed type. Possible values include 'rss2', 'atom'.
737 *                        Default is the value of get_default_feed().
738 * @return string The permalink for the comments feed for the given post on success, empty string on failure.
739 */
740function get_post_comments_feed_link( $post_id = 0, $feed = '' ) {
741	$post_id = absint( $post_id );
742
743	if ( ! $post_id ) {
744		$post_id = get_the_ID();
745	}
746
747	if ( empty( $feed ) ) {
748		$feed = get_default_feed();
749	}
750
751	$post = get_post( $post_id );
752
753	// Bail out if the post does not exist.
754	if ( ! $post instanceof WP_Post ) {
755		return '';
756	}
757
758	$unattached = 'attachment' === $post->post_type && 0 === (int) $post->post_parent;
759
760	if ( get_option( 'permalink_structure' ) ) {
761		if ( 'page' === get_option( 'show_on_front' ) && get_option( 'page_on_front' ) == $post_id ) {
762			$url = _get_page_link( $post_id );
763		} else {
764			$url = get_permalink( $post_id );
765		}
766
767		if ( $unattached ) {
768			$url = home_url( '/feed/' );
769			if ( get_default_feed() !== $feed ) {
770				$url .= "$feed/";
771			}
772			$url = add_query_arg( 'attachment_id', $post_id, $url );
773		} else {
774			$url = trailingslashit( $url ) . 'feed';
775			if ( get_default_feed() != $feed ) {
776				$url .= "/$feed";
777			}
778			$url = user_trailingslashit( $url, 'single_feed' );
779		}
780	} else {
781		if ( $unattached ) {
782			$url = add_query_arg(
783				array(
784					'feed'          => $feed,
785					'attachment_id' => $post_id,
786				),
787				home_url( '/' )
788			);
789		} elseif ( 'page' === $post->post_type ) {
790			$url = add_query_arg(
791				array(
792					'feed'    => $feed,
793					'page_id' => $post_id,
794				),
795				home_url( '/' )
796			);
797		} else {
798			$url = add_query_arg(
799				array(
800					'feed' => $feed,
801					'p'    => $post_id,
802				),
803				home_url( '/' )
804			);
805		}
806	}
807
808	/**
809	 * Filters the post comments feed permalink.
810	 *
811	 * @since 1.5.1
812	 *
813	 * @param string $url Post comments feed permalink.
814	 */
815	return apply_filters( 'post_comments_feed_link', $url );
816}
817
818/**
819 * Displays the comment feed link for a post.
820 *
821 * Prints out the comment feed link for a post. Link text is placed in the
822 * anchor. If no link text is specified, default text is used. If no post ID is
823 * specified, the current post is used.
824 *
825 * @since 2.5.0
826 *
827 * @param string $link_text Optional. Descriptive link text. Default 'Comments Feed'.
828 * @param int    $post_id   Optional. Post ID. Default is the ID of the global `$post`.
829 * @param string $feed      Optional. Feed type. Possible values include 'rss2', 'atom'.
830 *                          Default is the value of get_default_feed().
831 */
832function post_comments_feed_link( $link_text = '', $post_id = '', $feed = '' ) {
833	$url = get_post_comments_feed_link( $post_id, $feed );
834	if ( empty( $link_text ) ) {
835		$link_text = __( 'Comments Feed' );
836	}
837
838	$link = '<a href="' . esc_url( $url ) . '">' . $link_text . '</a>';
839	/**
840	 * Filters the post comment feed link anchor tag.
841	 *
842	 * @since 2.8.0
843	 *
844	 * @param string $link    The complete anchor tag for the comment feed link.
845	 * @param int    $post_id Post ID.
846	 * @param string $feed    The feed type. Possible values include 'rss2', 'atom',
847	 *                        or an empty string for the default feed type.
848	 */
849	echo apply_filters( 'post_comments_feed_link_html', $link, $post_id, $feed );
850}
851
852/**
853 * Retrieves the feed link for a given author.
854 *
855 * Returns a link to the feed for all posts by a given author. A specific feed
856 * can be requested or left blank to get the default feed.
857 *
858 * @since 2.5.0
859 *
860 * @param int    $author_id Author ID.
861 * @param string $feed      Optional. Feed type. Possible values include 'rss2', 'atom'.
862 *                          Default is the value of get_default_feed().
863 * @return string Link to the feed for the author specified by $author_id.
864 */
865function get_author_feed_link( $author_id, $feed = '' ) {
866	$author_id           = (int) $author_id;
867	$permalink_structure = get_option( 'permalink_structure' );
868
869	if ( empty( $feed ) ) {
870		$feed = get_default_feed();
871	}
872
873	if ( ! $permalink_structure ) {
874		$link = home_url( "?feed=$feed&amp;author=" . $author_id );
875	} else {
876		$link = get_author_posts_url( $author_id );
877		if ( get_default_feed() == $feed ) {
878			$feed_link = 'feed';
879		} else {
880			$feed_link = "feed/$feed";
881		}
882
883		$link = trailingslashit( $link ) . user_trailingslashit( $feed_link, 'feed' );
884	}
885
886	/**
887	 * Filters the feed link for a given author.
888	 *
889	 * @since 1.5.1
890	 *
891	 * @param string $link The author feed link.
892	 * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
893	 */
894	$link = apply_filters( 'author_feed_link', $link, $feed );
895
896	return $link;
897}
898
899/**
900 * Retrieves the feed link for a category.
901 *
902 * Returns a link to the feed for all posts in a given category. A specific feed
903 * can be requested or left blank to get the default feed.
904 *
905 * @since 2.5.0
906 *
907 * @param int    $cat_id Category ID.
908 * @param string $feed   Optional. Feed type. Possible values include 'rss2', 'atom'.
909 *                       Default is the value of get_default_feed().
910 * @return string Link to the feed for the category specified by $cat_id.
911 */
912function get_category_feed_link( $cat_id, $feed = '' ) {
913	return get_term_feed_link( $cat_id, 'category', $feed );
914}
915
916/**
917 * Retrieves the feed link for a term.
918 *
919 * Returns a link to the feed for all posts in a given term. A specific feed
920 * can be requested or left blank to get the default feed.
921 *
922 * @since 3.0.0
923 *
924 * @param int    $term_id  Term ID.
925 * @param string $taxonomy Optional. Taxonomy of `$term_id`. Default 'category'.
926 * @param string $feed     Optional. Feed type. Possible values include 'rss2', 'atom'.
927 *                         Default is the value of get_default_feed().
928 * @return string|false Link to the feed for the term specified by $term_id and $taxonomy.
929 */
930function get_term_feed_link( $term_id, $taxonomy = 'category', $feed = '' ) {
931	$term_id = (int) $term_id;
932
933	$term = get_term( $term_id, $taxonomy );
934
935	if ( empty( $term ) || is_wp_error( $term ) ) {
936		return false;
937	}
938
939	if ( empty( $feed ) ) {
940		$feed = get_default_feed();
941	}
942
943	$permalink_structure = get_option( 'permalink_structure' );
944
945	if ( ! $permalink_structure ) {
946		if ( 'category' === $taxonomy ) {
947			$link = home_url( "?feed=$feed&amp;cat=$term_id" );
948		} elseif ( 'post_tag' === $taxonomy ) {
949			$link = home_url( "?feed=$feed&amp;tag=$term->slug" );
950		} else {
951			$t    = get_taxonomy( $taxonomy );
952			$link = home_url( "?feed=$feed&amp;$t->query_var=$term->slug" );
953		}
954	} else {
955		$link = get_term_link( $term_id, $term->taxonomy );
956		if ( get_default_feed() == $feed ) {
957			$feed_link = 'feed';
958		} else {
959			$feed_link = "feed/$feed";
960		}
961
962		$link = trailingslashit( $link ) . user_trailingslashit( $feed_link, 'feed' );
963	}
964
965	if ( 'category' === $taxonomy ) {
966		/**
967		 * Filters the category feed link.
968		 *
969		 * @since 1.5.1
970		 *
971		 * @param string $link The category feed link.
972		 * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
973		 */
974		$link = apply_filters( 'category_feed_link', $link, $feed );
975	} elseif ( 'post_tag' === $taxonomy ) {
976		/**
977		 * Filters the post tag feed link.
978		 *
979		 * @since 2.3.0
980		 *
981		 * @param string $link The tag feed link.
982		 * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
983		 */
984		$link = apply_filters( 'tag_feed_link', $link, $feed );
985	} else {
986		/**
987		 * Filters the feed link for a taxonomy other than 'category' or 'post_tag'.
988		 *
989		 * @since 3.0.0
990		 *
991		 * @param string $link     The taxonomy feed link.
992		 * @param string $feed     Feed type. Possible values include 'rss2', 'atom'.
993		 * @param string $taxonomy The taxonomy name.
994		 */
995		$link = apply_filters( 'taxonomy_feed_link', $link, $feed, $taxonomy );
996	}
997
998	return $link;
999}
1000
1001/**
1002 * Retrieves the permalink for a tag feed.
1003 *
1004 * @since 2.3.0
1005 *
1006 * @param int    $tag_id Tag ID.
1007 * @param string $feed   Optional. Feed type. Possible values include 'rss2', 'atom'.
1008 *                       Default is the value of get_default_feed().
1009 * @return string The feed permalink for the given tag.
1010 */
1011function get_tag_feed_link( $tag_id, $feed = '' ) {
1012	return get_term_feed_link( $tag_id, 'post_tag', $feed );
1013}
1014
1015/**
1016 * Retrieves the edit link for a tag.
1017 *
1018 * @since 2.7.0
1019 *
1020 * @param int    $tag_id   Tag ID.
1021 * @param string $taxonomy Optional. Taxonomy slug. Default 'post_tag'.
1022 * @return string The edit tag link URL for the given tag.
1023 */
1024function get_edit_tag_link( $tag_id, $taxonomy = 'post_tag' ) {
1025	/**
1026	 * Filters the edit link for a tag (or term in another taxonomy).
1027	 *
1028	 * @since 2.7.0
1029	 *
1030	 * @param string $link The term edit link.
1031	 */
1032	return apply_filters( 'get_edit_tag_link', get_edit_term_link( $tag_id, $taxonomy ) );
1033}
1034
1035/**
1036 * Displays or retrieves the edit link for a tag with formatting.
1037 *
1038 * @since 2.7.0
1039 *
1040 * @param string  $link   Optional. Anchor text. If empty, default is 'Edit This'. Default empty.
1041 * @param string  $before Optional. Display before edit link. Default empty.
1042 * @param string  $after  Optional. Display after edit link. Default empty.
1043 * @param WP_Term $tag    Optional. Term object. If null, the queried object will be inspected.
1044 *                        Default null.
1045 */
1046function edit_tag_link( $link = '', $before = '', $after = '', $tag = null ) {
1047	$link = edit_term_link( $link, '', '', $tag, false );
1048
1049	/**
1050	 * Filters the anchor tag for the edit link for a tag (or term in another taxonomy).
1051	 *
1052	 * @since 2.7.0
1053	 *
1054	 * @param string $link The anchor tag for the edit link.
1055	 */
1056	echo $before . apply_filters( 'edit_tag_link', $link ) . $after;
1057}
1058
1059/**
1060 * Retrieves the URL for editing a given term.
1061 *
1062 * @since 3.1.0
1063 * @since 4.5.0 The `$taxonomy` parameter was made optional.
1064 *
1065 * @param int    $term_id     Term ID.
1066 * @param string $taxonomy    Optional. Taxonomy. Defaults to the taxonomy of the term identified
1067 *                            by `$term_id`.
1068 * @param string $object_type Optional. The object type. Used to highlight the proper post type
1069 *                            menu on the linked page. Defaults to the first object_type associated
1070 *                            with the taxonomy.
1071 * @return string|null The edit term link URL for the given term, or null on failure.
1072 */
1073function get_edit_term_link( $term_id, $taxonomy = '', $object_type = '' ) {
1074	$term = get_term( $term_id, $taxonomy );
1075	if ( ! $term || is_wp_error( $term ) ) {
1076		return;
1077	}
1078
1079	$tax = get_taxonomy( $term->taxonomy );
1080	if ( ! $tax || ! current_user_can( 'edit_term', $term->term_id ) ) {
1081		return;
1082	}
1083
1084	$args = array(
1085		'taxonomy' => $taxonomy,
1086		'tag_ID'   => $term->term_id,
1087	);
1088
1089	if ( $object_type ) {
1090		$args['post_type'] = $object_type;
1091	} elseif ( ! empty( $tax->object_type ) ) {
1092		$args['post_type'] = reset( $tax->object_type );
1093	}
1094
1095	if ( $tax->show_ui ) {
1096		$location = add_query_arg( $args, admin_url( 'term.php' ) );
1097	} else {
1098		$location = '';
1099	}
1100
1101	/**
1102	 * Filters the edit link for a term.
1103	 *
1104	 * @since 3.1.0
1105	 *
1106	 * @param string $location    The edit link.
1107	 * @param int    $term_id     Term ID.
1108	 * @param string $taxonomy    Taxonomy name.
1109	 * @param string $object_type The object type (eg. the post type).
1110	 */
1111	return apply_filters( 'get_edit_term_link', $location, $term_id, $taxonomy, $object_type );
1112}
1113
1114/**
1115 * Displays or retrieves the edit term link with formatting.
1116 *
1117 * @since 3.1.0
1118 *
1119 * @param string  $link   Optional. Anchor text. If empty, default is 'Edit This'. Default empty.
1120 * @param string  $before Optional. Display before edit link. Default empty.
1121 * @param string  $after  Optional. Display after edit link. Default empty.
1122 * @param WP_Term $term   Optional. Term object. If null, the queried object will be inspected. Default null.
1123 * @param bool    $echo   Optional. Whether or not to echo the return. Default true.
1124 * @return string|void HTML content.
1125 */
1126function edit_term_link( $link = '', $before = '', $after = '', $term = null, $echo = true ) {
1127	if ( is_null( $term ) ) {
1128		$term = get_queried_object();
1129	}
1130
1131	if ( ! $term ) {
1132		return;
1133	}
1134
1135	$tax = get_taxonomy( $term->taxonomy );
1136	if ( ! current_user_can( 'edit_term', $term->term_id ) ) {
1137		return;
1138	}
1139
1140	if ( empty( $link ) ) {
1141		$link = __( 'Edit This' );
1142	}
1143
1144	$link = '<a href="' . get_edit_term_link( $term->term_id, $term->taxonomy ) . '">' . $link . '</a>';
1145
1146	/**
1147	 * Filters the anchor tag for the edit link of a term.
1148	 *
1149	 * @since 3.1.0
1150	 *
1151	 * @param string $link    The anchor tag for the edit link.
1152	 * @param int    $term_id Term ID.
1153	 */
1154	$link = $before . apply_filters( 'edit_term_link', $link, $term->term_id ) . $after;
1155
1156	if ( $echo ) {
1157		echo $link;
1158	} else {
1159		return $link;
1160	}
1161}
1162
1163/**
1164 * Retrieves the permalink for a search.
1165 *
1166 * @since 3.0.0
1167 *
1168 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1169 *
1170 * @param string $query Optional. The query string to use. If empty the current query is used. Default empty.
1171 * @return string The search permalink.
1172 */
1173function get_search_link( $query = '' ) {
1174	global $wp_rewrite;
1175
1176	if ( empty( $query ) ) {
1177		$search = get_search_query( false );
1178	} else {
1179		$search = stripslashes( $query );
1180	}
1181
1182	$permastruct = $wp_rewrite->get_search_permastruct();
1183
1184	if ( empty( $permastruct ) ) {
1185		$link = home_url( '?s=' . urlencode( $search ) );
1186	} else {
1187		$search = urlencode( $search );
1188		$search = str_replace( '%2F', '/', $search ); // %2F(/) is not valid within a URL, send it un-encoded.
1189		$link   = str_replace( '%search%', $search, $permastruct );
1190		$link   = home_url( user_trailingslashit( $link, 'search' ) );
1191	}
1192
1193	/**
1194	 * Filters the search permalink.
1195	 *
1196	 * @since 3.0.0
1197	 *
1198	 * @param string $link   Search permalink.
1199	 * @param string $search The URL-encoded search term.
1200	 */
1201	return apply_filters( 'search_link', $link, $search );
1202}
1203
1204/**
1205 * Retrieves the permalink for the search results feed.
1206 *
1207 * @since 2.5.0
1208 *
1209 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1210 *
1211 * @param string $search_query Optional. Search query. Default empty.
1212 * @param string $feed         Optional. Feed type. Possible values include 'rss2', 'atom'.
1213 *                             Default is the value of get_default_feed().
1214 * @return string The search results feed permalink.
1215 */
1216function get_search_feed_link( $search_query = '', $feed = '' ) {
1217	global $wp_rewrite;
1218	$link = get_search_link( $search_query );
1219
1220	if ( empty( $feed ) ) {
1221		$feed = get_default_feed();
1222	}
1223
1224	$permastruct = $wp_rewrite->get_search_permastruct();
1225
1226	if ( empty( $permastruct ) ) {
1227		$link = add_query_arg( 'feed', $feed, $link );
1228	} else {
1229		$link  = trailingslashit( $link );
1230		$link .= "feed/$feed/";
1231	}
1232
1233	/**
1234	 * Filters the search feed link.
1235	 *
1236	 * @since 2.5.0
1237	 *
1238	 * @param string $link Search feed link.
1239	 * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
1240	 * @param string $type The search type. One of 'posts' or 'comments'.
1241	 */
1242	return apply_filters( 'search_feed_link', $link, $feed, 'posts' );
1243}
1244
1245/**
1246 * Retrieves the permalink for the search results comments feed.
1247 *
1248 * @since 2.5.0
1249 *
1250 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1251 *
1252 * @param string $search_query Optional. Search query. Default empty.
1253 * @param string $feed         Optional. Feed type. Possible values include 'rss2', 'atom'.
1254 *                             Default is the value of get_default_feed().
1255 * @return string The comments feed search results permalink.
1256 */
1257function get_search_comments_feed_link( $search_query = '', $feed = '' ) {
1258	global $wp_rewrite;
1259
1260	if ( empty( $feed ) ) {
1261		$feed = get_default_feed();
1262	}
1263
1264	$link = get_search_feed_link( $search_query, $feed );
1265
1266	$permastruct = $wp_rewrite->get_search_permastruct();
1267
1268	if ( empty( $permastruct ) ) {
1269		$link = add_query_arg( 'feed', 'comments-' . $feed, $link );
1270	} else {
1271		$link = add_query_arg( 'withcomments', 1, $link );
1272	}
1273
1274	/** This filter is documented in wp-includes/link-template.php */
1275	return apply_filters( 'search_feed_link', $link, $feed, 'comments' );
1276}
1277
1278/**
1279 * Retrieves the permalink for a post type archive.
1280 *
1281 * @since 3.1.0
1282 * @since 4.5.0 Support for posts was added.
1283 *
1284 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
1285 *
1286 * @param string $post_type Post type.
1287 * @return string|false The post type archive permalink. False if the post type
1288 *                      does not exist or does not have an archive.
1289 */
1290function get_post_type_archive_link( $post_type ) {
1291	global $wp_rewrite;
1292
1293	$post_type_obj = get_post_type_object( $post_type );
1294	if ( ! $post_type_obj ) {
1295		return false;
1296	}
1297
1298	if ( 'post' === $post_type ) {
1299		$show_on_front  = get_option( 'show_on_front' );
1300		$page_for_posts = get_option( 'page_for_posts' );
1301
1302		if ( 'page' === $show_on_front && $page_for_posts ) {
1303			$link = get_permalink( $page_for_posts );
1304		} else {
1305			$link = get_home_url();
1306		}
1307		/** This filter is documented in wp-includes/link-template.php */
1308		return apply_filters( 'post_type_archive_link', $link, $post_type );
1309	}
1310
1311	if ( ! $post_type_obj->has_archive ) {
1312		return false;
1313	}
1314
1315	if ( get_option( 'permalink_structure' ) && is_array( $post_type_obj->rewrite ) ) {
1316		$struct = ( true === $post_type_obj->has_archive ) ? $post_type_obj->rewrite['slug'] : $post_type_obj->has_archive;
1317		if ( $post_type_obj->rewrite['with_front'] ) {
1318			$struct = $wp_rewrite->front . $struct;
1319		} else {
1320			$struct = $wp_rewrite->root . $struct;
1321		}
1322		$link = home_url( user_trailingslashit( $struct, 'post_type_archive' ) );
1323	} else {
1324		$link = home_url( '?post_type=' . $post_type );
1325	}
1326
1327	/**
1328	 * Filters the post type archive permalink.
1329	 *
1330	 * @since 3.1.0
1331	 *
1332	 * @param string $link      The post type archive permalink.
1333	 * @param string $post_type Post type name.
1334	 */
1335	return apply_filters( 'post_type_archive_link', $link, $post_type );
1336}
1337
1338/**
1339 * Retrieves the permalink for a post type archive feed.
1340 *
1341 * @since 3.1.0
1342 *
1343 * @param string $post_type Post type.
1344 * @param string $feed      Optional. Feed type. Possible values include 'rss2', 'atom'.
1345 *                          Default is the value of get_default_feed().
1346 * @return string|false The post type feed permalink. False if the post type
1347 *                      does not exist or does not have an archive.
1348 */
1349function get_post_type_archive_feed_link( $post_type, $feed = '' ) {
1350	$default_feed = get_default_feed();
1351	if ( empty( $feed ) ) {
1352		$feed = $default_feed;
1353	}
1354
1355	$link = get_post_type_archive_link( $post_type );
1356	if ( ! $link ) {
1357		return false;
1358	}
1359
1360	$post_type_obj = get_post_type_object( $post_type );
1361	if ( get_option( 'permalink_structure' ) && is_array( $post_type_obj->rewrite ) && $post_type_obj->rewrite['feeds'] ) {
1362		$link  = trailingslashit( $link );
1363		$link .= 'feed/';
1364		if ( $feed != $default_feed ) {
1365			$link .= "$feed/";
1366		}
1367	} else {
1368		$link = add_query_arg( 'feed', $feed, $link );
1369	}
1370
1371	/**
1372	 * Filters the post type archive feed link.
1373	 *
1374	 * @since 3.1.0
1375	 *
1376	 * @param string $link The post type archive feed link.
1377	 * @param string $feed Feed type. Possible values include 'rss2', 'atom'.
1378	 */
1379	return apply_filters( 'post_type_archive_feed_link', $link, $feed );
1380}
1381
1382/**
1383 * Retrieves the URL used for the post preview.
1384 *
1385 * Allows additional query args to be appended.
1386 *
1387 * @since 4.4.0
1388 *
1389 * @param int|WP_Post $post         Optional. Post ID or `WP_Post` object. Defaults to global `$post`.
1390 * @param array       $query_args   Optional. Array of additional query args to be appended to the link.
1391 *                                  Default empty array.
1392 * @param string      $preview_link Optional. Base preview link to be used if it should differ from the
1393 *                                  post permalink. Default empty.
1394 * @return string|null URL used for the post preview, or null if the post does not exist.
1395 */
1396function get_preview_post_link( $post = null, $query_args = array(), $preview_link = '' ) {
1397	$post = get_post( $post );
1398	if ( ! $post ) {
1399		return;
1400	}
1401
1402	$post_type_object = get_post_type_object( $post->post_type );
1403	if ( is_post_type_viewable( $post_type_object ) ) {
1404		if ( ! $preview_link ) {
1405			$preview_link = set_url_scheme( get_permalink( $post ) );
1406		}
1407
1408		$query_args['preview'] = 'true';
1409		$preview_link          = add_query_arg( $query_args, $preview_link );
1410	}
1411
1412	/**
1413	 * Filters the URL used for a post preview.
1414	 *
1415	 * @since 2.0.5
1416	 * @since 4.0.0 Added the `$post` parameter.
1417	 *
1418	 * @param string  $preview_link URL used for the post preview.
1419	 * @param WP_Post $post         Post object.
1420	 */
1421	return apply_filters( 'preview_post_link', $preview_link, $post );
1422}
1423
1424/**
1425 * Retrieves the edit post link for post.
1426 *
1427 * Can be used within the WordPress loop or outside of it. Can be used with
1428 * pages, posts, attachments, and revisions.
1429 *
1430 * @since 2.3.0
1431 *
1432 * @param int|WP_Post $id      Optional. Post ID or post object. Default is the global `$post`.
1433 * @param string      $context Optional. How to output the '&' character. Default '&amp;'.
1434 * @return string|null The edit post link for the given post. Null if the post type does not exist
1435 *                     or does not allow an editing UI.
1436 */
1437function get_edit_post_link( $id = 0, $context = 'display' ) {
1438	$post = get_post( $id );
1439	if ( ! $post ) {
1440		return;
1441	}
1442
1443	if ( 'revision' === $post->post_type ) {
1444		$action = '';
1445	} elseif ( 'display' === $context ) {
1446		$action = '&amp;action=edit';
1447	} else {
1448		$action = '&action=edit';
1449	}
1450
1451	$post_type_object = get_post_type_object( $post->post_type );
1452	if ( ! $post_type_object ) {
1453		return;
1454	}
1455
1456	if ( ! current_user_can( 'edit_post', $post->ID ) ) {
1457		return;
1458	}
1459
1460	if ( $post_type_object->_edit_link ) {
1461		$link = admin_url( sprintf( $post_type_object->_edit_link . $action, $post->ID ) );
1462	} else {
1463		$link = '';
1464	}
1465
1466	/**
1467	 * Filters the post edit link.
1468	 *
1469	 * @since 2.3.0
1470	 *
1471	 * @param string $link    The edit link.
1472	 * @param int    $post_id Post ID.
1473	 * @param string $context The link context. If set to 'display' then ampersands
1474	 *                        are encoded.
1475	 */
1476	return apply_filters( 'get_edit_post_link', $link, $post->ID, $context );
1477}
1478
1479/**
1480 * Displays the edit post link for post.
1481 *
1482 * @since 1.0.0
1483 * @since 4.4.0 The `$class` argument was added.
1484 *
1485 * @param string      $text   Optional. Anchor text. If null, default is 'Edit This'. Default null.
1486 * @param string      $before Optional. Display before edit link. Default empty.
1487 * @param string      $after  Optional. Display after edit link. Default empty.
1488 * @param int|WP_Post $id     Optional. Post ID or post object. Default is the global `$post`.
1489 * @param string      $class  Optional. Add custom class to link. Default 'post-edit-link'.
1490 */
1491function edit_post_link( $text = null, $before = '', $after = '', $id = 0, $class = 'post-edit-link' ) {
1492	$post = get_post( $id );
1493	if ( ! $post ) {
1494		return;
1495	}
1496
1497	$url = get_edit_post_link( $post->ID );
1498	if ( ! $url ) {
1499		return;
1500	}
1501
1502	if ( null === $text ) {
1503		$text = __( 'Edit This' );
1504	}
1505
1506	$link = '<a class="' . esc_attr( $class ) . '" href="' . esc_url( $url ) . '">' . $text . '</a>';
1507
1508	/**
1509	 * Filters the post edit link anchor tag.
1510	 *
1511	 * @since 2.3.0
1512	 *
1513	 * @param string $link    Anchor tag for the edit link.
1514	 * @param int    $post_id Post ID.
1515	 * @param string $text    Anchor text.
1516	 */
1517	echo $before . apply_filters( 'edit_post_link', $link, $post->ID, $text ) . $after;
1518}
1519
1520/**
1521 * Retrieves the delete posts link for post.
1522 *
1523 * Can be used within the WordPress loop or outside of it, with any post type.
1524 *
1525 * @since 2.9.0
1526 *
1527 * @param int|WP_Post $id           Optional. Post ID or post object. Default is the global `$post`.
1528 * @param string      $deprecated   Not used.
1529 * @param bool        $force_delete Optional. Whether to bypass Trash and force deletion. Default false.
1530 * @return string|void The delete post link URL for the given post.
1531 */
1532function get_delete_post_link( $id = 0, $deprecated = '', $force_delete = false ) {
1533	if ( ! empty( $deprecated ) ) {
1534		_deprecated_argument( __FUNCTION__, '3.0.0' );
1535	}
1536
1537	$post = get_post( $id );
1538	if ( ! $post ) {
1539		return;
1540	}
1541
1542	$post_type_object = get_post_type_object( $post->post_type );
1543	if ( ! $post_type_object ) {
1544		return;
1545	}
1546
1547	if ( ! current_user_can( 'delete_post', $post->ID ) ) {
1548		return;
1549	}
1550
1551	$action = ( $force_delete || ! EMPTY_TRASH_DAYS ) ? 'delete' : 'trash';
1552
1553	$delete_link = add_query_arg( 'action', $action, admin_url( sprintf( $post_type_object->_edit_link, $post->ID ) ) );
1554
1555	/**
1556	 * Filters the post delete link.
1557	 *
1558	 * @since 2.9.0
1559	 *
1560	 * @param string $link         The delete link.
1561	 * @param int    $post_id      Post ID.
1562	 * @param bool   $force_delete Whether to bypass the Trash and force deletion. Default false.
1563	 */
1564	return apply_filters( 'get_delete_post_link', wp_nonce_url( $delete_link, "$action-post_{$post->ID}" ), $post->ID, $force_delete );
1565}
1566
1567/**
1568 * Retrieves the edit comment link.
1569 *
1570 * @since 2.3.0
1571 *
1572 * @param int|WP_Comment $comment_id Optional. Comment ID or WP_Comment object.
1573 * @return string|void The edit comment link URL for the given comment.
1574 */
1575function get_edit_comment_link( $comment_id = 0 ) {
1576	$comment = get_comment( $comment_id );
1577
1578	if ( ! current_user_can( 'edit_comment', $comment->comment_ID ) ) {
1579		return;
1580	}
1581
1582	$location = admin_url( 'comment.php?action=editcomment&amp;c=' ) . $comment->comment_ID;
1583
1584	/**
1585	 * Filters the comment edit link.
1586	 *
1587	 * @since 2.3.0
1588	 *
1589	 * @param string $location The edit link.
1590	 */
1591	return apply_filters( 'get_edit_comment_link', $location );
1592}
1593
1594/**
1595 * Displays the edit comment link with formatting.
1596 *
1597 * @since 1.0.0
1598 *
1599 * @param string $text   Optional. Anchor text. If null, default is 'Edit This'. Default null.
1600 * @param string $before Optional. Display before edit link. Default empty.
1601 * @param string $after  Optional. Display after edit link. Default empty.
1602 */
1603function edit_comment_link( $text = null, $before = '', $after = '' ) {
1604	$comment = get_comment();
1605
1606	if ( ! current_user_can( 'edit_comment', $comment->comment_ID ) ) {
1607		return;
1608	}
1609
1610	if ( null === $text ) {
1611		$text = __( 'Edit This' );
1612	}
1613
1614	$link = '<a class="comment-edit-link" href="' . esc_url( get_edit_comment_link( $comment ) ) . '">' . $text . '</a>';
1615
1616	/**
1617	 * Filters the comment edit link anchor tag.
1618	 *
1619	 * @since 2.3.0
1620	 *
1621	 * @param string $link       Anchor tag for the edit link.
1622	 * @param int    $comment_id Comment ID.
1623	 * @param string $text       Anchor text.
1624	 */
1625	echo $before . apply_filters( 'edit_comment_link', $link, $comment->comment_ID, $text ) . $after;
1626}
1627
1628/**
1629 * Displays the edit bookmark link.
1630 *
1631 * @since 2.7.0
1632 *
1633 * @param int|stdClass $link Optional. Bookmark ID. Default is the ID of the current bookmark.
1634 * @return string|void The edit bookmark link URL.
1635 */
1636function get_edit_bookmark_link( $link = 0 ) {
1637	$link = get_bookmark( $link );
1638
1639	if ( ! current_user_can( 'manage_links' ) ) {
1640		return;
1641	}
1642
1643	$location = admin_url( 'link.php?action=edit&amp;link_id=' ) . $link->link_id;
1644
1645	/**
1646	 * Filters the bookmark edit link.
1647	 *
1648	 * @since 2.7.0
1649	 *
1650	 * @param string $location The edit link.
1651	 * @param int    $link_id  Bookmark ID.
1652	 */
1653	return apply_filters( 'get_edit_bookmark_link', $location, $link->link_id );
1654}
1655
1656/**
1657 * Displays the edit bookmark link anchor content.
1658 *
1659 * @since 2.7.0
1660 *
1661 * @param string $link     Optional. Anchor text. If empty, default is 'Edit This'. Default empty.
1662 * @param string $before   Optional. Display before edit link. Default empty.
1663 * @param string $after    Optional. Display after edit link. Default empty.
1664 * @param int    $bookmark Optional. Bookmark ID. Default is the current bookmark.
1665 */
1666function edit_bookmark_link( $link = '', $before = '', $after = '', $bookmark = null ) {
1667	$bookmark = get_bookmark( $bookmark );
1668
1669	if ( ! current_user_can( 'manage_links' ) ) {
1670		return;
1671	}
1672
1673	if ( empty( $link ) ) {
1674		$link = __( 'Edit This' );
1675	}
1676
1677	$link = '<a href="' . esc_url( get_edit_bookmark_link( $bookmark ) ) . '">' . $link . '</a>';
1678
1679	/**
1680	 * Filters the bookmark edit link anchor tag.
1681	 *
1682	 * @since 2.7.0
1683	 *
1684	 * @param string $link    Anchor tag for the edit link.
1685	 * @param int    $link_id Bookmark ID.
1686	 */
1687	echo $before . apply_filters( 'edit_bookmark_link', $link, $bookmark->link_id ) . $after;
1688}
1689
1690/**
1691 * Retrieves the edit user link.
1692 *
1693 * @since 3.5.0
1694 *
1695 * @param int $user_id Optional. User ID. Defaults to the current user.
1696 * @return string URL to edit user page or empty string.
1697 */
1698function get_edit_user_link( $user_id = null ) {
1699	if ( ! $user_id ) {
1700		$user_id = get_current_user_id();
1701	}
1702
1703	if ( empty( $user_id ) || ! current_user_can( 'edit_user', $user_id ) ) {
1704		return '';
1705	}
1706
1707	$user = get_userdata( $user_id );
1708
1709	if ( ! $user ) {
1710		return '';
1711	}
1712
1713	if ( get_current_user_id() == $user->ID ) {
1714		$link = get_edit_profile_url( $user->ID );
1715	} else {
1716		$link = add_query_arg( 'user_id', $user->ID, self_admin_url( 'user-edit.php' ) );
1717	}
1718
1719	/**
1720	 * Filters the user edit link.
1721	 *
1722	 * @since 3.5.0
1723	 *
1724	 * @param string $link    The edit link.
1725	 * @param int    $user_id User ID.
1726	 */
1727	return apply_filters( 'get_edit_user_link', $link, $user->ID );
1728}
1729
1730//
1731// Navigation links.
1732//
1733
1734/**
1735 * Retrieves the previous post that is adjacent to the current post.
1736 *
1737 * @since 1.5.0
1738 *
1739 * @param bool         $in_same_term   Optional. Whether post should be in a same taxonomy term. Default false.
1740 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs. Default empty.
1741 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
1742 * @return null|string|WP_Post Post object if successful. Null if global $post is not set. Empty string if no
1743 *                             corresponding post exists.
1744 */
1745function get_previous_post( $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
1746	return get_adjacent_post( $in_same_term, $excluded_terms, true, $taxonomy );
1747}
1748
1749/**
1750 * Retrieves the next post that is adjacent to the current post.
1751 *
1752 * @since 1.5.0
1753 *
1754 * @param bool         $in_same_term   Optional. Whether post should be in a same taxonomy term. Default false.
1755 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs. Default empty.
1756 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
1757 * @return null|string|WP_Post Post object if successful. Null if global $post is not set. Empty string if no
1758 *                             corresponding post exists.
1759 */
1760function get_next_post( $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
1761	return get_adjacent_post( $in_same_term, $excluded_terms, false, $taxonomy );
1762}
1763
1764/**
1765 * Retrieves the adjacent post.
1766 *
1767 * Can either be next or previous post.
1768 *
1769 * @since 2.5.0
1770 *
1771 * @global wpdb $wpdb WordPress database abstraction object.
1772 *
1773 * @param bool         $in_same_term   Optional. Whether post should be in a same taxonomy term. Default false.
1774 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs. Default empty string.
1775 * @param bool         $previous       Optional. Whether to retrieve previous post. Default true
1776 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
1777 * @return null|string|WP_Post Post object if successful. Null if global $post is not set. Empty string if no
1778 *                             corresponding post exists.
1779 */
1780function get_adjacent_post( $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
1781	global $wpdb;
1782
1783	$post = get_post();
1784	if ( ! $post || ! taxonomy_exists( $taxonomy ) ) {
1785		return null;
1786	}
1787
1788	$current_post_date = $post->post_date;
1789
1790	$join     = '';
1791	$where    = '';
1792	$adjacent = $previous ? 'previous' : 'next';
1793
1794	if ( ! empty( $excluded_terms ) && ! is_array( $excluded_terms ) ) {
1795		// Back-compat, $excluded_terms used to be $excluded_categories with IDs separated by " and ".
1796		if ( false !== strpos( $excluded_terms, ' and ' ) ) {
1797			_deprecated_argument(
1798				__FUNCTION__,
1799				'3.3.0',
1800				sprintf(
1801					/* translators: %s: The word 'and'. */
1802					__( 'Use commas instead of %s to separate excluded terms.' ),
1803					"'and'"
1804				)
1805			);
1806			$excluded_terms = explode( ' and ', $excluded_terms );
1807		} else {
1808			$excluded_terms = explode( ',', $excluded_terms );
1809		}
1810
1811		$excluded_terms = array_map( 'intval', $excluded_terms );
1812	}
1813
1814	/**
1815	 * Filters the IDs of terms excluded from adjacent post queries.
1816	 *
1817	 * The dynamic portion of the hook name, `$adjacent`, refers to the type
1818	 * of adjacency, 'next' or 'previous'.
1819	 *
1820	 * Possible hook names include:
1821	 *
1822	 *  - `get_next_post_excluded_terms`
1823	 *  - `get_previous_post_excluded_terms`
1824	 *
1825	 * @since 4.4.0
1826	 *
1827	 * @param array|string $excluded_terms Array of excluded term IDs. Empty string if none were provided.
1828	 */
1829	$excluded_terms = apply_filters( "get_{$adjacent}_post_excluded_terms", $excluded_terms );
1830
1831	if ( $in_same_term || ! empty( $excluded_terms ) ) {
1832		if ( $in_same_term ) {
1833			$join  .= " INNER JOIN $wpdb->term_relationships AS tr ON p.ID = tr.object_id INNER JOIN $wpdb->term_taxonomy tt ON tr.term_taxonomy_id = tt.term_taxonomy_id";
1834			$where .= $wpdb->prepare( 'AND tt.taxonomy = %s', $taxonomy );
1835
1836			if ( ! is_object_in_taxonomy( $post->post_type, $taxonomy ) ) {
1837				return '';
1838			}
1839			$term_array = wp_get_object_terms( $post->ID, $taxonomy, array( 'fields' => 'ids' ) );
1840
1841			// Remove any exclusions from the term array to include.
1842			$term_array = array_diff( $term_array, (array) $excluded_terms );
1843			$term_array = array_map( 'intval', $term_array );
1844
1845			if ( ! $term_array || is_wp_error( $term_array ) ) {
1846				return '';
1847			}
1848
1849			$where .= ' AND tt.term_id IN (' . implode( ',', $term_array ) . ')';
1850		}
1851
1852		if ( ! empty( $excluded_terms ) ) {
1853			$where .= " AND p.ID NOT IN ( SELECT tr.object_id FROM $wpdb->term_relationships tr LEFT JOIN $wpdb->term_taxonomy tt ON (tr.term_taxonomy_id = tt.term_taxonomy_id) WHERE tt.term_id IN (" . implode( ',', array_map( 'intval', $excluded_terms ) ) . ') )';
1854		}
1855	}
1856
1857	// 'post_status' clause depends on the current user.
1858	if ( is_user_logged_in() ) {
1859		$user_id = get_current_user_id();
1860
1861		$post_type_object = get_post_type_object( $post->post_type );
1862		if ( empty( $post_type_object ) ) {
1863			$post_type_cap    = $post->post_type;
1864			$read_private_cap = 'read_private_' . $post_type_cap . 's';
1865		} else {
1866			$read_private_cap = $post_type_object->cap->read_private_posts;
1867		}
1868
1869		/*
1870		 * Results should include private posts belonging to the current user, or private posts where the
1871		 * current user has the 'read_private_posts' cap.
1872		 */
1873		$private_states = get_post_stati( array( 'private' => true ) );
1874		$where         .= " AND ( p.post_status = 'publish'";
1875		foreach ( (array) $private_states as $state ) {
1876			if ( current_user_can( $read_private_cap ) ) {
1877				$where .= $wpdb->prepare( ' OR p.post_status = %s', $state );
1878			} else {
1879				$where .= $wpdb->prepare( ' OR (p.post_author = %d AND p.post_status = %s)', $user_id, $state );
1880			}
1881		}
1882		$where .= ' )';
1883	} else {
1884		$where .= " AND p.post_status = 'publish'";
1885	}
1886
1887	$op    = $previous ? '<' : '>';
1888	$order = $previous ? 'DESC' : 'ASC';
1889
1890	/**
1891	 * Filters the JOIN clause in the SQL for an adjacent post query.
1892	 *
1893	 * The dynamic portion of the hook name, `$adjacent`, refers to the type
1894	 * of adjacency, 'next' or 'previous'.
1895	 *
1896	 * Possible hook names include:
1897	 *
1898	 *  - `get_next_post_join`
1899	 *  - `get_previous_post_join`
1900	 *
1901	 * @since 2.5.0
1902	 * @since 4.4.0 Added the `$taxonomy` and `$post` parameters.
1903	 *
1904	 * @param string  $join           The JOIN clause in the SQL.
1905	 * @param bool    $in_same_term   Whether post should be in a same taxonomy term.
1906	 * @param array   $excluded_terms Array of excluded term IDs.
1907	 * @param string  $taxonomy       Taxonomy. Used to identify the term used when `$in_same_term` is true.
1908	 * @param WP_Post $post           WP_Post object.
1909	 */
1910	$join = apply_filters( "get_{$adjacent}_post_join", $join, $in_same_term, $excluded_terms, $taxonomy, $post );
1911
1912	/**
1913	 * Filters the WHERE clause in the SQL for an adjacent post query.
1914	 *
1915	 * The dynamic portion of the hook name, `$adjacent`, refers to the type
1916	 * of adjacency, 'next' or 'previous'.
1917	 *
1918	 * Possible hook names include:
1919	 *
1920	 *  - `get_next_post_where`
1921	 *  - `get_previous_post_where`
1922	 *
1923	 * @since 2.5.0
1924	 * @since 4.4.0 Added the `$taxonomy` and `$post` parameters.
1925	 *
1926	 * @param string  $where          The `WHERE` clause in the SQL.
1927	 * @param bool    $in_same_term   Whether post should be in a same taxonomy term.
1928	 * @param array   $excluded_terms Array of excluded term IDs.
1929	 * @param string  $taxonomy       Taxonomy. Used to identify the term used when `$in_same_term` is true.
1930	 * @param WP_Post $post           WP_Post object.
1931	 */
1932	$where = apply_filters( "get_{$adjacent}_post_where", $wpdb->prepare( "WHERE p.post_date $op %s AND p.post_type = %s $where", $current_post_date, $post->post_type ), $in_same_term, $excluded_terms, $taxonomy, $post );
1933
1934	/**
1935	 * Filters the ORDER BY clause in the SQL for an adjacent post query.
1936	 *
1937	 * The dynamic portion of the hook name, `$adjacent`, refers to the type
1938	 * of adjacency, 'next' or 'previous'.
1939	 *
1940	 * Possible hook names include:
1941	 *
1942	 *  - `get_next_post_sort`
1943	 *  - `get_previous_post_sort`
1944	 *
1945	 * @since 2.5.0
1946	 * @since 4.4.0 Added the `$post` parameter.
1947	 * @since 4.9.0 Added the `$order` parameter.
1948	 *
1949	 * @param string $order_by The `ORDER BY` clause in the SQL.
1950	 * @param WP_Post $post    WP_Post object.
1951	 * @param string  $order   Sort order. 'DESC' for previous post, 'ASC' for next.
1952	 */
1953	$sort = apply_filters( "get_{$adjacent}_post_sort", "ORDER BY p.post_date $order LIMIT 1", $post, $order );
1954
1955	$query     = "SELECT p.ID FROM $wpdb->posts AS p $join $where $sort";
1956	$query_key = 'adjacent_post_' . md5( $query );
1957	$result    = wp_cache_get( $query_key, 'counts' );
1958	if ( false !== $result ) {
1959		if ( $result ) {
1960			$result = get_post( $result );
1961		}
1962		return $result;
1963	}
1964
1965	$result = $wpdb->get_var( $query );
1966	if ( null === $result ) {
1967		$result = '';
1968	}
1969
1970	wp_cache_set( $query_key, $result, 'counts' );
1971
1972	if ( $result ) {
1973		$result = get_post( $result );
1974	}
1975
1976	return $result;
1977}
1978
1979/**
1980 * Retrieves the adjacent post relational link.
1981 *
1982 * Can either be next or previous post relational link.
1983 *
1984 * @since 2.8.0
1985 *
1986 * @param string       $title          Optional. Link title format. Default '%title'.
1987 * @param bool         $in_same_term   Optional. Whether link should be in a same taxonomy term. Default false.
1988 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs. Default empty.
1989 * @param bool         $previous       Optional. Whether to display link to previous or next post. Default true.
1990 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
1991 * @return string|void The adjacent post relational link URL.
1992 */
1993function get_adjacent_post_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
1994	$post = get_post();
1995	if ( $previous && is_attachment() && $post ) {
1996		$post = get_post( $post->post_parent );
1997	} else {
1998		$post = get_adjacent_post( $in_same_term, $excluded_terms, $previous, $taxonomy );
1999	}
2000
2001	if ( empty( $post ) ) {
2002		return;
2003	}
2004
2005	$post_title = the_title_attribute(
2006		array(
2007			'echo' => false,
2008			'post' => $post,
2009		)
2010	);
2011
2012	if ( empty( $post_title ) ) {
2013		$post_title = $previous ? __( 'Previous Post' ) : __( 'Next Post' );
2014	}
2015
2016	$date = mysql2date( get_option( 'date_format' ), $post->post_date );
2017
2018	$title = str_replace( '%title', $post_title, $title );
2019	$title = str_replace( '%date', $date, $title );
2020
2021	$link  = $previous ? "<link rel='prev' title='" : "<link rel='next' title='";
2022	$link .= esc_attr( $title );
2023	$link .= "' href='" . get_permalink( $post ) . "' />\n";
2024
2025	$adjacent = $previous ? 'previous' : 'next';
2026
2027	/**
2028	 * Filters the adjacent post relational link.
2029	 *
2030	 * The dynamic portion of the hook name, `$adjacent`, refers to the type
2031	 * of adjacency, 'next' or 'previous'.
2032	 *
2033	 * Possible hook names include:
2034	 *
2035	 *  - `next_post_rel_link`
2036	 *  - `previous_post_rel_link`
2037	 *
2038	 * @since 2.8.0
2039	 *
2040	 * @param string $link The relational link.
2041	 */
2042	return apply_filters( "{$adjacent}_post_rel_link", $link );
2043}
2044
2045/**
2046 * Displays the relational links for the posts adjacent to the current post.
2047 *
2048 * @since 2.8.0
2049 *
2050 * @param string       $title          Optional. Link title format. Default '%title'.
2051 * @param bool         $in_same_term   Optional. Whether link should be in a same taxonomy term. Default false.
2052 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs. Default empty.
2053 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
2054 */
2055function adjacent_posts_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2056	echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, true, $taxonomy );
2057	echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, false, $taxonomy );
2058}
2059
2060/**
2061 * Displays relational links for the posts adjacent to the current post for single post pages.
2062 *
2063 * This is meant to be attached to actions like 'wp_head'. Do not call this directly in plugins
2064 * or theme templates.
2065 *
2066 * @since 3.0.0
2067 * @since 5.6.0 No longer used in core.
2068 *
2069 * @see adjacent_posts_rel_link()
2070 */
2071function adjacent_posts_rel_link_wp_head() {
2072	if ( ! is_single() || is_attachment() ) {
2073		return;
2074	}
2075	adjacent_posts_rel_link();
2076}
2077
2078/**
2079 * Displays the relational link for the next post adjacent to the current post.
2080 *
2081 * @since 2.8.0
2082 *
2083 * @see get_adjacent_post_rel_link()
2084 *
2085 * @param string       $title          Optional. Link title format. Default '%title'.
2086 * @param bool         $in_same_term   Optional. Whether link should be in a same taxonomy term. Default false.
2087 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs. Default empty.
2088 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
2089 */
2090function next_post_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2091	echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, false, $taxonomy );
2092}
2093
2094/**
2095 * Displays the relational link for the previous post adjacent to the current post.
2096 *
2097 * @since 2.8.0
2098 *
2099 * @see get_adjacent_post_rel_link()
2100 *
2101 * @param string       $title          Optional. Link title format. Default '%title'.
2102 * @param bool         $in_same_term   Optional. Whether link should be in a same taxonomy term. Default false.
2103 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs. Default true.
2104 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
2105 */
2106function prev_post_rel_link( $title = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2107	echo get_adjacent_post_rel_link( $title, $in_same_term, $excluded_terms, true, $taxonomy );
2108}
2109
2110/**
2111 * Retrieves the boundary post.
2112 *
2113 * Boundary being either the first or last post by publish date within the constraints specified
2114 * by $in_same_term or $excluded_terms.
2115 *
2116 * @since 2.8.0
2117 *
2118 * @param bool         $in_same_term   Optional. Whether returned post should be in a same taxonomy term.
2119 *                                     Default false.
2120 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs.
2121 *                                     Default empty.
2122 * @param bool         $start          Optional. Whether to retrieve first or last post. Default true
2123 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
2124 * @return null|array Array containing the boundary post object if successful, null otherwise.
2125 */
2126function get_boundary_post( $in_same_term = false, $excluded_terms = '', $start = true, $taxonomy = 'category' ) {
2127	$post = get_post();
2128	if ( ! $post || ! is_single() || is_attachment() || ! taxonomy_exists( $taxonomy ) ) {
2129		return null;
2130	}
2131
2132	$query_args = array(
2133		'posts_per_page'         => 1,
2134		'order'                  => $start ? 'ASC' : 'DESC',
2135		'update_post_term_cache' => false,
2136		'update_post_meta_cache' => false,
2137	);
2138
2139	$term_array = array();
2140
2141	if ( ! is_array( $excluded_terms ) ) {
2142		if ( ! empty( $excluded_terms ) ) {
2143			$excluded_terms = explode( ',', $excluded_terms );
2144		} else {
2145			$excluded_terms = array();
2146		}
2147	}
2148
2149	if ( $in_same_term || ! empty( $excluded_terms ) ) {
2150		if ( $in_same_term ) {
2151			$term_array = wp_get_object_terms( $post->ID, $taxonomy, array( 'fields' => 'ids' ) );
2152		}
2153
2154		if ( ! empty( $excluded_terms ) ) {
2155			$excluded_terms = array_map( 'intval', $excluded_terms );
2156			$excluded_terms = array_diff( $excluded_terms, $term_array );
2157
2158			$inverse_terms = array();
2159			foreach ( $excluded_terms as $excluded_term ) {
2160				$inverse_terms[] = $excluded_term * -1;
2161			}
2162			$excluded_terms = $inverse_terms;
2163		}
2164
2165		$query_args['tax_query'] = array(
2166			array(
2167				'taxonomy' => $taxonomy,
2168				'terms'    => array_merge( $term_array, $excluded_terms ),
2169			),
2170		);
2171	}
2172
2173	return get_posts( $query_args );
2174}
2175
2176/**
2177 * Retrieves the previous post link that is adjacent to the current post.
2178 *
2179 * @since 3.7.0
2180 *
2181 * @param string       $format         Optional. Link anchor format. Default '&laquo; %link'.
2182 * @param string       $link           Optional. Link permalink format. Default '%title'.
2183 * @param bool         $in_same_term   Optional. Whether link should be in a same taxonomy term. Default false.
2184 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs. Default empty.
2185 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
2186 * @return string The link URL of the previous post in relation to the current post.
2187 */
2188function get_previous_post_link( $format = '&laquo; %link', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2189	return get_adjacent_post_link( $format, $link, $in_same_term, $excluded_terms, true, $taxonomy );
2190}
2191
2192/**
2193 * Displays the previous post link that is adjacent to the current post.
2194 *
2195 * @since 1.5.0
2196 *
2197 * @see get_previous_post_link()
2198 *
2199 * @param string       $format         Optional. Link anchor format. Default '&laquo; %link'.
2200 * @param string       $link           Optional. Link permalink format. Default '%title'.
2201 * @param bool         $in_same_term   Optional. Whether link should be in a same taxonomy term. Default false.
2202 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs. Default empty.
2203 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
2204 */
2205function previous_post_link( $format = '&laquo; %link', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2206	echo get_previous_post_link( $format, $link, $in_same_term, $excluded_terms, $taxonomy );
2207}
2208
2209/**
2210 * Retrieves the next post link that is adjacent to the current post.
2211 *
2212 * @since 3.7.0
2213 *
2214 * @param string       $format         Optional. Link anchor format. Default '&laquo; %link'.
2215 * @param string       $link           Optional. Link permalink format. Default '%title'.
2216 * @param bool         $in_same_term   Optional. Whether link should be in a same taxonomy term. Default false.
2217 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs. Default empty.
2218 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
2219 * @return string The link URL of the next post in relation to the current post.
2220 */
2221function get_next_post_link( $format = '%link &raquo;', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2222	return get_adjacent_post_link( $format, $link, $in_same_term, $excluded_terms, false, $taxonomy );
2223}
2224
2225/**
2226 * Displays the next post link that is adjacent to the current post.
2227 *
2228 * @since 1.5.0
2229 *
2230 * @see get_next_post_link()
2231 *
2232 * @param string       $format         Optional. Link anchor format. Default '&laquo; %link'.
2233 * @param string       $link           Optional. Link permalink format. Default '%title'
2234 * @param bool         $in_same_term   Optional. Whether link should be in a same taxonomy term. Default false.
2235 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded term IDs. Default empty.
2236 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
2237 */
2238function next_post_link( $format = '%link &raquo;', $link = '%title', $in_same_term = false, $excluded_terms = '', $taxonomy = 'category' ) {
2239	echo get_next_post_link( $format, $link, $in_same_term, $excluded_terms, $taxonomy );
2240}
2241
2242/**
2243 * Retrieves the adjacent post link.
2244 *
2245 * Can be either next post link or previous.
2246 *
2247 * @since 3.7.0
2248 *
2249 * @param string       $format         Link anchor format.
2250 * @param string       $link           Link permalink format.
2251 * @param bool         $in_same_term   Optional. Whether link should be in a same taxonomy term. Default false.
2252 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded terms IDs. Default empty.
2253 * @param bool         $previous       Optional. Whether to display link to previous or next post. Default true.
2254 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
2255 * @return string The link URL of the previous or next post in relation to the current post.
2256 */
2257function get_adjacent_post_link( $format, $link, $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
2258	if ( $previous && is_attachment() ) {
2259		$post = get_post( get_post()->post_parent );
2260	} else {
2261		$post = get_adjacent_post( $in_same_term, $excluded_terms, $previous, $taxonomy );
2262	}
2263
2264	if ( ! $post ) {
2265		$output = '';
2266	} else {
2267		$title = $post->post_title;
2268
2269		if ( empty( $post->post_title ) ) {
2270			$title = $previous ? __( 'Previous Post' ) : __( 'Next Post' );
2271		}
2272
2273		/** This filter is documented in wp-includes/post-template.php */
2274		$title = apply_filters( 'the_title', $title, $post->ID );
2275
2276		$date = mysql2date( get_option( 'date_format' ), $post->post_date );
2277		$rel  = $previous ? 'prev' : 'next';
2278
2279		$string = '<a href="' . get_permalink( $post ) . '" rel="' . $rel . '">';
2280		$inlink = str_replace( '%title', $title, $link );
2281		$inlink = str_replace( '%date', $date, $inlink );
2282		$inlink = $string . $inlink . '</a>';
2283
2284		$output = str_replace( '%link', $inlink, $format );
2285	}
2286
2287	$adjacent = $previous ? 'previous' : 'next';
2288
2289	/**
2290	 * Filters the adjacent post link.
2291	 *
2292	 * The dynamic portion of the hook name, `$adjacent`, refers to the type
2293	 * of adjacency, 'next' or 'previous'.
2294	 *
2295	 * Possible hook names include:
2296	 *
2297	 *  - `next_post_link`
2298	 *  - `previous_post_link`
2299	 *
2300	 * @since 2.6.0
2301	 * @since 4.2.0 Added the `$adjacent` parameter.
2302	 *
2303	 * @param string  $output   The adjacent post link.
2304	 * @param string  $format   Link anchor format.
2305	 * @param string  $link     Link permalink format.
2306	 * @param WP_Post $post     The adjacent post.
2307	 * @param string  $adjacent Whether the post is previous or next.
2308	 */
2309	return apply_filters( "{$adjacent}_post_link", $output, $format, $link, $post, $adjacent );
2310}
2311
2312/**
2313 * Displays the adjacent post link.
2314 *
2315 * Can be either next post link or previous.
2316 *
2317 * @since 2.5.0
2318 *
2319 * @param string       $format         Link anchor format.
2320 * @param string       $link           Link permalink format.
2321 * @param bool         $in_same_term   Optional. Whether link should be in a same taxonomy term. Default false.
2322 * @param int[]|string $excluded_terms Optional. Array or comma-separated list of excluded category IDs. Default empty.
2323 * @param bool         $previous       Optional. Whether to display link to previous or next post. Default true.
2324 * @param string       $taxonomy       Optional. Taxonomy, if $in_same_term is true. Default 'category'.
2325 */
2326function adjacent_post_link( $format, $link, $in_same_term = false, $excluded_terms = '', $previous = true, $taxonomy = 'category' ) {
2327	echo get_adjacent_post_link( $format, $link, $in_same_term, $excluded_terms, $previous, $taxonomy );
2328}
2329
2330/**
2331 * Retrieves the link for a page number.
2332 *
2333 * @since 1.5.0
2334 *
2335 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
2336 *
2337 * @param int  $pagenum Optional. Page number. Default 1.
2338 * @param bool $escape  Optional. Whether to escape the URL for display, with esc_url(). Defaults to true.
2339 *                      Otherwise, prepares the URL with esc_url_raw().
2340 * @return string The link URL for the given page number.
2341 */
2342function get_pagenum_link( $pagenum = 1, $escape = true ) {
2343	global $wp_rewrite;
2344
2345	$pagenum = (int) $pagenum;
2346
2347	$request = remove_query_arg( 'paged' );
2348
2349	$home_root = parse_url( home_url() );
2350	$home_root = ( isset( $home_root['path'] ) ) ? $home_root['path'] : '';
2351	$home_root = preg_quote( $home_root, '|' );
2352
2353	$request = preg_replace( '|^' . $home_root . '|i', '', $request );
2354	$request = preg_replace( '|^/+|', '', $request );
2355
2356	if ( ! $wp_rewrite->using_permalinks() || is_admin() ) {
2357		$base = trailingslashit( get_bloginfo( 'url' ) );
2358
2359		if ( $pagenum > 1 ) {
2360			$result = add_query_arg( 'paged', $pagenum, $base . $request );
2361		} else {
2362			$result = $base . $request;
2363		}
2364	} else {
2365		$qs_regex = '|\?.*?$|';
2366		preg_match( $qs_regex, $request, $qs_match );
2367
2368		if ( ! empty( $qs_match[0] ) ) {
2369			$query_string = $qs_match[0];
2370			$request      = preg_replace( $qs_regex, '', $request );
2371		} else {
2372			$query_string = '';
2373		}
2374
2375		$request = preg_replace( "|$wp_rewrite->pagination_base/\d+/?$|", '', $request );
2376		$request = preg_replace( '|^' . preg_quote( $wp_rewrite->index, '|' ) . '|i', '', $request );
2377		$request = ltrim( $request, '/' );
2378
2379		$base = trailingslashit( get_bloginfo( 'url' ) );
2380
2381		if ( $wp_rewrite->using_index_permalinks() && ( $pagenum > 1 || '' !== $request ) ) {
2382			$base .= $wp_rewrite->index . '/';
2383		}
2384
2385		if ( $pagenum > 1 ) {
2386			$request = ( ( ! empty( $request ) ) ? trailingslashit( $request ) : $request ) . user_trailingslashit( $wp_rewrite->pagination_base . '/' . $pagenum, 'paged' );
2387		}
2388
2389		$result = $base . $request . $query_string;
2390	}
2391
2392	/**
2393	 * Filters the page number link for the current request.
2394	 *
2395	 * @since 2.5.0
2396	 * @since 5.2.0 Added the `$pagenum` argument.
2397	 *
2398	 * @param string $result  The page number link.
2399	 * @param int    $pagenum The page number.
2400	 */
2401	$result = apply_filters( 'get_pagenum_link', $result, $pagenum );
2402
2403	if ( $escape ) {
2404		return esc_url( $result );
2405	} else {
2406		return esc_url_raw( $result );
2407	}
2408}
2409
2410/**
2411 * Retrieves the next posts page link.
2412 *
2413 * Backported from 2.1.3 to 2.0.10.
2414 *
2415 * @since 2.0.10
2416 *
2417 * @global int $paged
2418 *
2419 * @param int $max_page Optional. Max pages. Default 0.
2420 * @return string|void The link URL for next posts page.
2421 */
2422function get_next_posts_page_link( $max_page = 0 ) {
2423	global $paged;
2424
2425	if ( ! is_single() ) {
2426		if ( ! $paged ) {
2427			$paged = 1;
2428		}
2429		$nextpage = (int) $paged + 1;
2430		if ( ! $max_page || $max_page >= $nextpage ) {
2431			return get_pagenum_link( $nextpage );
2432		}
2433	}
2434}
2435
2436/**
2437 * Displays or retrieves the next posts page link.
2438 *
2439 * @since 0.71
2440 *
2441 * @param int  $max_page Optional. Max pages. Default 0.
2442 * @param bool $echo     Optional. Whether to echo the link. Default true.
2443 * @return string|void The link URL for next posts page if `$echo = false`.
2444 */
2445function next_posts( $max_page = 0, $echo = true ) {
2446	$output = esc_url( get_next_posts_page_link( $max_page ) );
2447
2448	if ( $echo ) {
2449		echo $output;
2450	} else {
2451		return $output;
2452	}
2453}
2454
2455/**
2456 * Retrieves the next posts page link.
2457 *
2458 * @since 2.7.0
2459 *
2460 * @global int      $paged
2461 * @global WP_Query $wp_query WordPress Query object.
2462 *
2463 * @param string $label    Content for link text.
2464 * @param int    $max_page Optional. Max pages. Default 0.
2465 * @return string|void HTML-formatted next posts page link.
2466 */
2467function get_next_posts_link( $label = null, $max_page = 0 ) {
2468	global $paged, $wp_query;
2469
2470	if ( ! $max_page ) {
2471		$max_page = $wp_query->max_num_pages;
2472	}
2473
2474	if ( ! $paged ) {
2475		$paged = 1;
2476	}
2477
2478	$nextpage = (int) $paged + 1;
2479
2480	if ( null === $label ) {
2481		$label = __( 'Next Page &raquo;' );
2482	}
2483
2484	if ( ! is_single() && ( $nextpage <= $max_page ) ) {
2485		/**
2486		 * Filters the anchor tag attributes for the next posts page link.
2487		 *
2488		 * @since 2.7.0
2489		 *
2490		 * @param string $attributes Attributes for the anchor tag.
2491		 */
2492		$attr = apply_filters( 'next_posts_link_attributes', '' );
2493
2494		return '<a href="' . next_posts( $max_page, false ) . "\" $attr>" . preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label ) . '</a>';
2495	}
2496}
2497
2498/**
2499 * Displays the next posts page link.
2500 *
2501 * @since 0.71
2502 *
2503 * @param string $label    Content for link text.
2504 * @param int    $max_page Optional. Max pages. Default 0.
2505 */
2506function next_posts_link( $label = null, $max_page = 0 ) {
2507	echo get_next_posts_link( $label, $max_page );
2508}
2509
2510/**
2511 * Retrieves the previous posts page link.
2512 *
2513 * Will only return string, if not on a single page or post.
2514 *
2515 * Backported to 2.0.10 from 2.1.3.
2516 *
2517 * @since 2.0.10
2518 *
2519 * @global int $paged
2520 *
2521 * @return string|void The link for the previous posts page.
2522 */
2523function get_previous_posts_page_link() {
2524	global $paged;
2525
2526	if ( ! is_single() ) {
2527		$nextpage = (int) $paged - 1;
2528		if ( $nextpage < 1 ) {
2529			$nextpage = 1;
2530		}
2531		return get_pagenum_link( $nextpage );
2532	}
2533}
2534
2535/**
2536 * Displays or retrieves the previous posts page link.
2537 *
2538 * @since 0.71
2539 *
2540 * @param bool $echo Optional. Whether to echo the link. Default true.
2541 * @return string|void The previous posts page link if `$echo = false`.
2542 */
2543function previous_posts( $echo = true ) {
2544	$output = esc_url( get_previous_posts_page_link() );
2545
2546	if ( $echo ) {
2547		echo $output;
2548	} else {
2549		return $output;
2550	}
2551}
2552
2553/**
2554 * Retrieves the previous posts page link.
2555 *
2556 * @since 2.7.0
2557 *
2558 * @global int $paged
2559 *
2560 * @param string $label Optional. Previous page link text.
2561 * @return string|void HTML-formatted previous page link.
2562 */
2563function get_previous_posts_link( $label = null ) {
2564	global $paged;
2565
2566	if ( null === $label ) {
2567		$label = __( '&laquo; Previous Page' );
2568	}
2569
2570	if ( ! is_single() && $paged > 1 ) {
2571		/**
2572		 * Filters the anchor tag attributes for the previous posts page link.
2573		 *
2574		 * @since 2.7.0
2575		 *
2576		 * @param string $attributes Attributes for the anchor tag.
2577		 */
2578		$attr = apply_filters( 'previous_posts_link_attributes', '' );
2579		return '<a href="' . previous_posts( false ) . "\" $attr>" . preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label ) . '</a>';
2580	}
2581}
2582
2583/**
2584 * Displays the previous posts page link.
2585 *
2586 * @since 0.71
2587 *
2588 * @param string $label Optional. Previous page link text.
2589 */
2590function previous_posts_link( $label = null ) {
2591	echo get_previous_posts_link( $label );
2592}
2593
2594/**
2595 * Retrieves the post pages link navigation for previous and next pages.
2596 *
2597 * @since 2.8.0
2598 *
2599 * @global WP_Query $wp_query WordPress Query object.
2600 *
2601 * @param string|array $args {
2602 *     Optional. Arguments to build the post pages link navigation.
2603 *
2604 *     @type string $sep      Separator character. Default '&#8212;'.
2605 *     @type string $prelabel Link text to display for the previous page link.
2606 *                            Default '&laquo; Previous Page'.
2607 *     @type string $nxtlabel Link text to display for the next page link.
2608 *                            Default 'Next Page &raquo;'.
2609 * }
2610 * @return string The posts link navigation.
2611 */
2612function get_posts_nav_link( $args = array() ) {
2613	global $wp_query;
2614
2615	$return = '';
2616
2617	if ( ! is_singular() ) {
2618		$defaults = array(
2619			'sep'      => ' &#8212; ',
2620			'prelabel' => __( '&laquo; Previous Page' ),
2621			'nxtlabel' => __( 'Next Page &raquo;' ),
2622		);
2623		$args     = wp_parse_args( $args, $defaults );
2624
2625		$max_num_pages = $wp_query->max_num_pages;
2626		$paged         = get_query_var( 'paged' );
2627
2628		// Only have sep if there's both prev and next results.
2629		if ( $paged < 2 || $paged >= $max_num_pages ) {
2630			$args['sep'] = '';
2631		}
2632
2633		if ( $max_num_pages > 1 ) {
2634			$return  = get_previous_posts_link( $args['prelabel'] );
2635			$return .= preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $args['sep'] );
2636			$return .= get_next_posts_link( $args['nxtlabel'] );
2637		}
2638	}
2639	return $return;
2640
2641}
2642
2643/**
2644 * Displays the post pages link navigation for previous and next pages.
2645 *
2646 * @since 0.71
2647 *
2648 * @param string $sep      Optional. Separator for posts navigation links. Default empty.
2649 * @param string $prelabel Optional. Label for previous pages. Default empty.
2650 * @param string $nxtlabel Optional Label for next pages. Default empty.
2651 */
2652function posts_nav_link( $sep = '', $prelabel = '', $nxtlabel = '' ) {
2653	$args = array_filter( compact( 'sep', 'prelabel', 'nxtlabel' ) );
2654	echo get_posts_nav_link( $args );
2655}
2656
2657/**
2658 * Retrieves the navigation to next/previous post, when applicable.
2659 *
2660 * @since 4.1.0
2661 * @since 4.4.0 Introduced the `in_same_term`, `excluded_terms`, and `taxonomy` arguments.
2662 * @since 5.3.0 Added the `aria_label` parameter.
2663 * @since 5.5.0 Added the `class` parameter.
2664 *
2665 * @param array $args {
2666 *     Optional. Default post navigation arguments. Default empty array.
2667 *
2668 *     @type string       $prev_text          Anchor text to display in the previous post link. Default '%title'.
2669 *     @type string       $next_text          Anchor text to display in the next post link. Default '%title'.
2670 *     @type bool         $in_same_term       Whether link should be in a same taxonomy term. Default false.
2671 *     @type int[]|string $excluded_terms     Array or comma-separated list of excluded term IDs. Default empty.
2672 *     @type string       $taxonomy           Taxonomy, if `$in_same_term` is true. Default 'category'.
2673 *     @type string       $screen_reader_text Screen reader text for the nav element. Default 'Post navigation'.
2674 *     @type string       $aria_label         ARIA label text for the nav element. Default 'Posts'.
2675 *     @type string       $class              Custom class for the nav element. Default 'post-navigation'.
2676 * }
2677 * @return string Markup for post links.
2678 */
2679function get_the_post_navigation( $args = array() ) {
2680	// Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
2681	if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
2682		$args['aria_label'] = $args['screen_reader_text'];
2683	}
2684
2685	$args = wp_parse_args(
2686		$args,
2687		array(
2688			'prev_text'          => '%title',
2689			'next_text'          => '%title',
2690			'in_same_term'       => false,
2691			'excluded_terms'     => '',
2692			'taxonomy'           => 'category',
2693			'screen_reader_text' => __( 'Post navigation' ),
2694			'aria_label'         => __( 'Posts' ),
2695			'class'              => 'post-navigation',
2696		)
2697	);
2698
2699	$navigation = '';
2700
2701	$previous = get_previous_post_link(
2702		'<div class="nav-previous">%link</div>',
2703		$args['prev_text'],
2704		$args['in_same_term'],
2705		$args['excluded_terms'],
2706		$args['taxonomy']
2707	);
2708
2709	$next = get_next_post_link(
2710		'<div class="nav-next">%link</div>',
2711		$args['next_text'],
2712		$args['in_same_term'],
2713		$args['excluded_terms'],
2714		$args['taxonomy']
2715	);
2716
2717	// Only add markup if there's somewhere to navigate to.
2718	if ( $previous || $next ) {
2719		$navigation = _navigation_markup( $previous . $next, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
2720	}
2721
2722	return $navigation;
2723}
2724
2725/**
2726 * Displays the navigation to next/previous post, when applicable.
2727 *
2728 * @since 4.1.0
2729 *
2730 * @param array $args Optional. See get_the_post_navigation() for available arguments.
2731 *                    Default empty array.
2732 */
2733function the_post_navigation( $args = array() ) {
2734	echo get_the_post_navigation( $args );
2735}
2736
2737/**
2738 * Returns the navigation to next/previous set of posts, when applicable.
2739 *
2740 * @since 4.1.0
2741 * @since 5.3.0 Added the `aria_label` parameter.
2742 * @since 5.5.0 Added the `class` parameter.
2743 *
2744 * @global WP_Query $wp_query WordPress Query object.
2745 *
2746 * @param array $args {
2747 *     Optional. Default posts navigation arguments. Default empty array.
2748 *
2749 *     @type string $prev_text          Anchor text to display in the previous posts link.
2750 *                                      Default 'Older posts'.
2751 *     @type string $next_text          Anchor text to display in the next posts link.
2752 *                                      Default 'Newer posts'.
2753 *     @type string $screen_reader_text Screen reader text for the nav element.
2754 *                                      Default 'Posts navigation'.
2755 *     @type string $aria_label         ARIA label text for the nav element. Default 'Posts'.
2756 *     @type string $class              Custom class for the nav element. Default 'posts-navigation'.
2757 * }
2758 * @return string Markup for posts links.
2759 */
2760function get_the_posts_navigation( $args = array() ) {
2761	$navigation = '';
2762
2763	// Don't print empty markup if there's only one page.
2764	if ( $GLOBALS['wp_query']->max_num_pages > 1 ) {
2765		// Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
2766		if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
2767			$args['aria_label'] = $args['screen_reader_text'];
2768		}
2769
2770		$args = wp_parse_args(
2771			$args,
2772			array(
2773				'prev_text'          => __( 'Older posts' ),
2774				'next_text'          => __( 'Newer posts' ),
2775				'screen_reader_text' => __( 'Posts navigation' ),
2776				'aria_label'         => __( 'Posts' ),
2777				'class'              => 'posts-navigation',
2778			)
2779		);
2780
2781		$next_link = get_previous_posts_link( $args['next_text'] );
2782		$prev_link = get_next_posts_link( $args['prev_text'] );
2783
2784		if ( $prev_link ) {
2785			$navigation .= '<div class="nav-previous">' . $prev_link . '</div>';
2786		}
2787
2788		if ( $next_link ) {
2789			$navigation .= '<div class="nav-next">' . $next_link . '</div>';
2790		}
2791
2792		$navigation = _navigation_markup( $navigation, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
2793	}
2794
2795	return $navigation;
2796}
2797
2798/**
2799 * Displays the navigation to next/previous set of posts, when applicable.
2800 *
2801 * @since 4.1.0
2802 *
2803 * @param array $args Optional. See get_the_posts_navigation() for available arguments.
2804 *                    Default empty array.
2805 */
2806function the_posts_navigation( $args = array() ) {
2807	echo get_the_posts_navigation( $args );
2808}
2809
2810/**
2811 * Retrieves a paginated navigation to next/previous set of posts, when applicable.
2812 *
2813 * @since 4.1.0
2814 * @since 5.3.0 Added the `aria_label` parameter.
2815 * @since 5.5.0 Added the `class` parameter.
2816 *
2817 * @param array $args {
2818 *     Optional. Default pagination arguments, see paginate_links().
2819 *
2820 *     @type string $screen_reader_text Screen reader text for navigation element.
2821 *                                      Default 'Posts navigation'.
2822 *     @type string $aria_label         ARIA label text for the nav element. Default 'Posts'.
2823 *     @type string $class              Custom class for the nav element. Default 'pagination'.
2824 * }
2825 * @return string Markup for pagination links.
2826 */
2827function get_the_posts_pagination( $args = array() ) {
2828	$navigation = '';
2829
2830	// Don't print empty markup if there's only one page.
2831	if ( $GLOBALS['wp_query']->max_num_pages > 1 ) {
2832		// Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
2833		if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
2834			$args['aria_label'] = $args['screen_reader_text'];
2835		}
2836
2837		$args = wp_parse_args(
2838			$args,
2839			array(
2840				'mid_size'           => 1,
2841				'prev_text'          => _x( 'Previous', 'previous set of posts' ),
2842				'next_text'          => _x( 'Next', 'next set of posts' ),
2843				'screen_reader_text' => __( 'Posts navigation' ),
2844				'aria_label'         => __( 'Posts' ),
2845				'class'              => 'pagination',
2846			)
2847		);
2848
2849		// Make sure we get a string back. Plain is the next best thing.
2850		if ( isset( $args['type'] ) && 'array' === $args['type'] ) {
2851			$args['type'] = 'plain';
2852		}
2853
2854		// Set up paginated links.
2855		$links = paginate_links( $args );
2856
2857		if ( $links ) {
2858			$navigation = _navigation_markup( $links, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
2859		}
2860	}
2861
2862	return $navigation;
2863}
2864
2865/**
2866 * Displays a paginated navigation to next/previous set of posts, when applicable.
2867 *
2868 * @since 4.1.0
2869 *
2870 * @param array $args Optional. See get_the_posts_pagination() for available arguments.
2871 *                    Default empty array.
2872 */
2873function the_posts_pagination( $args = array() ) {
2874	echo get_the_posts_pagination( $args );
2875}
2876
2877/**
2878 * Wraps passed links in navigational markup.
2879 *
2880 * @since 4.1.0
2881 * @since 5.3.0 Added the `aria_label` parameter.
2882 * @access private
2883 *
2884 * @param string $links              Navigational links.
2885 * @param string $class              Optional. Custom class for the nav element.
2886 *                                   Default 'posts-navigation'.
2887 * @param string $screen_reader_text Optional. Screen reader text for the nav element.
2888 *                                   Default 'Posts navigation'.
2889 * @param string $aria_label         Optional. ARIA label for the nav element.
2890 *                                   Defaults to the value of `$screen_reader_text`.
2891 * @return string Navigation template tag.
2892 */
2893function _navigation_markup( $links, $class = 'posts-navigation', $screen_reader_text = '', $aria_label = '' ) {
2894	if ( empty( $screen_reader_text ) ) {
2895		$screen_reader_text = __( 'Posts navigation' );
2896	}
2897	if ( empty( $aria_label ) ) {
2898		$aria_label = $screen_reader_text;
2899	}
2900
2901	$template = '
2902	<nav class="navigation %1$s" role="navigation" aria-label="%4$s">
2903		<h2 class="screen-reader-text">%2$s</h2>
2904		<div class="nav-links">%3$s</div>
2905	</nav>';
2906
2907	/**
2908	 * Filters the navigation markup template.
2909	 *
2910	 * Note: The filtered template HTML must contain specifiers for the navigation
2911	 * class (%1$s), the screen-reader-text value (%2$s), placement of the navigation
2912	 * links (%3$s), and ARIA label text if screen-reader-text does not fit that (%4$s):
2913	 *
2914	 *     <nav class="navigation %1$s" role="navigation" aria-label="%4$s">
2915	 *         <h2 class="screen-reader-text">%2$s</h2>
2916	 *         <div class="nav-links">%3$s</div>
2917	 *     </nav>
2918	 *
2919	 * @since 4.4.0
2920	 *
2921	 * @param string $template The default template.
2922	 * @param string $class    The class passed by the calling function.
2923	 * @return string Navigation template.
2924	 */
2925	$template = apply_filters( 'navigation_markup_template', $template, $class );
2926
2927	return sprintf( $template, sanitize_html_class( $class ), esc_html( $screen_reader_text ), $links, esc_html( $aria_label ) );
2928}
2929
2930/**
2931 * Retrieves the comments page number link.
2932 *
2933 * @since 2.7.0
2934 *
2935 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
2936 *
2937 * @param int $pagenum  Optional. Page number. Default 1.
2938 * @param int $max_page Optional. The maximum number of comment pages. Default 0.
2939 * @return string The comments page number link URL.
2940 */
2941function get_comments_pagenum_link( $pagenum = 1, $max_page = 0 ) {
2942	global $wp_rewrite;
2943
2944	$pagenum = (int) $pagenum;
2945
2946	$result = get_permalink();
2947
2948	if ( 'newest' === get_option( 'default_comments_page' ) ) {
2949		if ( $pagenum != $max_page ) {
2950			if ( $wp_rewrite->using_permalinks() ) {
2951				$result = user_trailingslashit( trailingslashit( $result ) . $wp_rewrite->comments_pagination_base . '-' . $pagenum, 'commentpaged' );
2952			} else {
2953				$result = add_query_arg( 'cpage', $pagenum, $result );
2954			}
2955		}
2956	} elseif ( $pagenum > 1 ) {
2957		if ( $wp_rewrite->using_permalinks() ) {
2958			$result = user_trailingslashit( trailingslashit( $result ) . $wp_rewrite->comments_pagination_base . '-' . $pagenum, 'commentpaged' );
2959		} else {
2960			$result = add_query_arg( 'cpage', $pagenum, $result );
2961		}
2962	}
2963
2964	$result .= '#comments';
2965
2966	/**
2967	 * Filters the comments page number link for the current request.
2968	 *
2969	 * @since 2.7.0
2970	 *
2971	 * @param string $result The comments page number link.
2972	 */
2973	return apply_filters( 'get_comments_pagenum_link', $result );
2974}
2975
2976/**
2977 * Retrieves the link to the next comments page.
2978 *
2979 * @since 2.7.1
2980 *
2981 * @global WP_Query $wp_query WordPress Query object.
2982 *
2983 * @param string $label    Optional. Label for link text. Default empty.
2984 * @param int    $max_page Optional. Max page. Default 0.
2985 * @return string|void HTML-formatted link for the next page of comments.
2986 */
2987function get_next_comments_link( $label = '', $max_page = 0 ) {
2988	global $wp_query;
2989
2990	if ( ! is_singular() ) {
2991		return;
2992	}
2993
2994	$page = get_query_var( 'cpage' );
2995
2996	if ( ! $page ) {
2997		$page = 1;
2998	}
2999
3000	$nextpage = (int) $page + 1;
3001
3002	if ( empty( $max_page ) ) {
3003		$max_page = $wp_query->max_num_comment_pages;
3004	}
3005
3006	if ( empty( $max_page ) ) {
3007		$max_page = get_comment_pages_count();
3008	}
3009
3010	if ( $nextpage > $max_page ) {
3011		return;
3012	}
3013
3014	if ( empty( $label ) ) {
3015		$label = __( 'Newer Comments &raquo;' );
3016	}
3017
3018	/**
3019	 * Filters the anchor tag attributes for the next comments page link.
3020	 *
3021	 * @since 2.7.0
3022	 *
3023	 * @param string $attributes Attributes for the anchor tag.
3024	 */
3025	return '<a href="' . esc_url( get_comments_pagenum_link( $nextpage, $max_page ) ) . '" ' . apply_filters( 'next_comments_link_attributes', '' ) . '>' . preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label ) . '</a>';
3026}
3027
3028/**
3029 * Displays the link to the next comments page.
3030 *
3031 * @since 2.7.0
3032 *
3033 * @param string $label    Optional. Label for link text. Default empty.
3034 * @param int    $max_page Optional. Max page. Default 0.
3035 */
3036function next_comments_link( $label = '', $max_page = 0 ) {
3037	echo get_next_comments_link( $label, $max_page );
3038}
3039
3040/**
3041 * Retrieves the link to the previous comments page.
3042 *
3043 * @since 2.7.1
3044 *
3045 * @param string $label Optional. Label for comments link text. Default empty.
3046 * @return string|void HTML-formatted link for the previous page of comments.
3047 */
3048function get_previous_comments_link( $label = '' ) {
3049	if ( ! is_singular() ) {
3050		return;
3051	}
3052
3053	$page = get_query_var( 'cpage' );
3054
3055	if ( (int) $page <= 1 ) {
3056		return;
3057	}
3058
3059	$prevpage = (int) $page - 1;
3060
3061	if ( empty( $label ) ) {
3062		$label = __( '&laquo; Older Comments' );
3063	}
3064
3065	/**
3066	 * Filters the anchor tag attributes for the previous comments page link.
3067	 *
3068	 * @since 2.7.0
3069	 *
3070	 * @param string $attributes Attributes for the anchor tag.
3071	 */
3072	return '<a href="' . esc_url( get_comments_pagenum_link( $prevpage ) ) . '" ' . apply_filters( 'previous_comments_link_attributes', '' ) . '>' . preg_replace( '/&([^#])(?![a-z]{1,8};)/i', '&#038;$1', $label ) . '</a>';
3073}
3074
3075/**
3076 * Displays the link to the previous comments page.
3077 *
3078 * @since 2.7.0
3079 *
3080 * @param string $label Optional. Label for comments link text. Default empty.
3081 */
3082function previous_comments_link( $label = '' ) {
3083	echo get_previous_comments_link( $label );
3084}
3085
3086/**
3087 * Displays or retrieves pagination links for the comments on the current post.
3088 *
3089 * @see paginate_links()
3090 * @since 2.7.0
3091 *
3092 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
3093 *
3094 * @param string|array $args Optional args. See paginate_links(). Default empty array.
3095 * @return void|string|array Void if 'echo' argument is true and 'type' is not an array,
3096 *                           or if the query is not for an existing single post of any post type.
3097 *                           Otherwise, markup for comment page links or array of comment page links,
3098 *                           depending on 'type' argument.
3099 */
3100function paginate_comments_links( $args = array() ) {
3101	global $wp_rewrite;
3102
3103	if ( ! is_singular() ) {
3104		return;
3105	}
3106
3107	$page = get_query_var( 'cpage' );
3108	if ( ! $page ) {
3109		$page = 1;
3110	}
3111	$max_page = get_comment_pages_count();
3112	$defaults = array(
3113		'base'         => add_query_arg( 'cpage', '%#%' ),
3114		'format'       => '',
3115		'total'        => $max_page,
3116		'current'      => $page,
3117		'echo'         => true,
3118		'type'         => 'plain',
3119		'add_fragment' => '#comments',
3120	);
3121	if ( $wp_rewrite->using_permalinks() ) {
3122		$defaults['base'] = user_trailingslashit( trailingslashit( get_permalink() ) . $wp_rewrite->comments_pagination_base . '-%#%', 'commentpaged' );
3123	}
3124
3125	$args       = wp_parse_args( $args, $defaults );
3126	$page_links = paginate_links( $args );
3127
3128	if ( $args['echo'] && 'array' !== $args['type'] ) {
3129		echo $page_links;
3130	} else {
3131		return $page_links;
3132	}
3133}
3134
3135/**
3136 * Retrieves navigation to next/previous set of comments, when applicable.
3137 *
3138 * @since 4.4.0
3139 * @since 5.3.0 Added the `aria_label` parameter.
3140 * @since 5.5.0 Added the `class` parameter.
3141 *
3142 * @param array $args {
3143 *     Optional. Default comments navigation arguments.
3144 *
3145 *     @type string $prev_text          Anchor text to display in the previous comments link.
3146 *                                      Default 'Older comments'.
3147 *     @type string $next_text          Anchor text to display in the next comments link.
3148 *                                      Default 'Newer comments'.
3149 *     @type string $screen_reader_text Screen reader text for the nav element. Default 'Comments navigation'.
3150 *     @type string $aria_label         ARIA label text for the nav element. Default 'Comments'.
3151 *     @type string $class              Custom class for the nav element. Default 'comment-navigation'.
3152 * }
3153 * @return string Markup for comments links.
3154 */
3155function get_the_comments_navigation( $args = array() ) {
3156	$navigation = '';
3157
3158	// Are there comments to navigate through?
3159	if ( get_comment_pages_count() > 1 ) {
3160		// Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
3161		if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
3162			$args['aria_label'] = $args['screen_reader_text'];
3163		}
3164
3165		$args = wp_parse_args(
3166			$args,
3167			array(
3168				'prev_text'          => __( 'Older comments' ),
3169				'next_text'          => __( 'Newer comments' ),
3170				'screen_reader_text' => __( 'Comments navigation' ),
3171				'aria_label'         => __( 'Comments' ),
3172				'class'              => 'comment-navigation',
3173			)
3174		);
3175
3176		$prev_link = get_previous_comments_link( $args['prev_text'] );
3177		$next_link = get_next_comments_link( $args['next_text'] );
3178
3179		if ( $prev_link ) {
3180			$navigation .= '<div class="nav-previous">' . $prev_link . '</div>';
3181		}
3182
3183		if ( $next_link ) {
3184			$navigation .= '<div class="nav-next">' . $next_link . '</div>';
3185		}
3186
3187		$navigation = _navigation_markup( $navigation, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
3188	}
3189
3190	return $navigation;
3191}
3192
3193/**
3194 * Displays navigation to next/previous set of comments, when applicable.
3195 *
3196 * @since 4.4.0
3197 *
3198 * @param array $args See get_the_comments_navigation() for available arguments. Default empty array.
3199 */
3200function the_comments_navigation( $args = array() ) {
3201	echo get_the_comments_navigation( $args );
3202}
3203
3204/**
3205 * Retrieves a paginated navigation to next/previous set of comments, when applicable.
3206 *
3207 * @since 4.4.0
3208 * @since 5.3.0 Added the `aria_label` parameter.
3209 * @since 5.5.0 Added the `class` parameter.
3210 *
3211 * @see paginate_comments_links()
3212 *
3213 * @param array $args {
3214 *     Optional. Default pagination arguments.
3215 *
3216 *     @type string $screen_reader_text Screen reader text for the nav element. Default 'Comments navigation'.
3217 *     @type string $aria_label         ARIA label text for the nav element. Default 'Comments'.
3218 *     @type string $class              Custom class for the nav element. Default 'comments-pagination'.
3219 * }
3220 * @return string Markup for pagination links.
3221 */
3222function get_the_comments_pagination( $args = array() ) {
3223	$navigation = '';
3224
3225	// Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
3226	if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
3227		$args['aria_label'] = $args['screen_reader_text'];
3228	}
3229
3230	$args         = wp_parse_args(
3231		$args,
3232		array(
3233			'screen_reader_text' => __( 'Comments navigation' ),
3234			'aria_label'         => __( 'Comments' ),
3235			'class'              => 'comments-pagination',
3236		)
3237	);
3238	$args['echo'] = false;
3239
3240	// Make sure we get a string back. Plain is the next best thing.
3241	if ( isset( $args['type'] ) && 'array' === $args['type'] ) {
3242		$args['type'] = 'plain';
3243	}
3244
3245	$links = paginate_comments_links( $args );
3246
3247	if ( $links ) {
3248		$navigation = _navigation_markup( $links, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
3249	}
3250
3251	return $navigation;
3252}
3253
3254/**
3255 * Displays a paginated navigation to next/previous set of comments, when applicable.
3256 *
3257 * @since 4.4.0
3258 *
3259 * @param array $args See get_the_comments_pagination() for available arguments. Default empty array.
3260 */
3261function the_comments_pagination( $args = array() ) {
3262	echo get_the_comments_pagination( $args );
3263}
3264
3265/**
3266 * Retrieves the URL for the current site where the front end is accessible.
3267 *
3268 * Returns the 'home' option with the appropriate protocol. The protocol will be 'https'
3269 * if is_ssl() evaluates to true; otherwise, it will be the same as the 'home' option.
3270 * If `$scheme` is 'http' or 'https', is_ssl() is overridden.
3271 *
3272 * @since 3.0.0
3273 *
3274 * @param string      $path   Optional. Path relative to the home URL. Default empty.
3275 * @param string|null $scheme Optional. Scheme to give the home URL context. Accepts
3276 *                            'http', 'https', 'relative', 'rest', or null. Default null.
3277 * @return string Home URL link with optional path appended.
3278 */
3279function home_url( $path = '', $scheme = null ) {
3280	return get_home_url( null, $path, $scheme );
3281}
3282
3283/**
3284 * Retrieves the URL for a given site where the front end is accessible.
3285 *
3286 * Returns the 'home' option with the appropriate protocol. The protocol will be 'https'
3287 * if is_ssl() evaluates to true; otherwise, it will be the same as the 'home' option.
3288 * If `$scheme` is 'http' or 'https', is_ssl() is overridden.
3289 *
3290 * @since 3.0.0
3291 *
3292 * @param int|null    $blog_id Optional. Site ID. Default null (current site).
3293 * @param string      $path    Optional. Path relative to the home URL. Default empty.
3294 * @param string|null $scheme  Optional. Scheme to give the home URL context. Accepts
3295 *                             'http', 'https', 'relative', 'rest', or null. Default null.
3296 * @return string Home URL link with optional path appended.
3297 */
3298function get_home_url( $blog_id = null, $path = '', $scheme = null ) {
3299	$orig_scheme = $scheme;
3300
3301	if ( empty( $blog_id ) || ! is_multisite() ) {
3302		$url = get_option( 'home' );
3303	} else {
3304		switch_to_blog( $blog_id );
3305		$url = get_option( 'home' );
3306		restore_current_blog();
3307	}
3308
3309	if ( ! in_array( $scheme, array( 'http', 'https', 'relative' ), true ) ) {
3310		if ( is_ssl() ) {
3311			$scheme = 'https';
3312		} else {
3313			$scheme = parse_url( $url, PHP_URL_SCHEME );
3314		}
3315	}
3316
3317	$url = set_url_scheme( $url, $scheme );
3318
3319	if ( $path && is_string( $path ) ) {
3320		$url .= '/' . ltrim( $path, '/' );
3321	}
3322
3323	/**
3324	 * Filters the home URL.
3325	 *
3326	 * @since 3.0.0
3327	 *
3328	 * @param string      $url         The complete home URL including scheme and path.
3329	 * @param string      $path        Path relative to the home URL. Blank string if no path is specified.
3330	 * @param string|null $orig_scheme Scheme to give the home URL context. Accepts 'http', 'https',
3331	 *                                 'relative', 'rest', or null.
3332	 * @param int|null    $blog_id     Site ID, or null for the current site.
3333	 */
3334	return apply_filters( 'home_url', $url, $path, $orig_scheme, $blog_id );
3335}
3336
3337/**
3338 * Retrieves the URL for the current site where WordPress application files
3339 * (e.g. wp-blog-header.php or the wp-admin/ folder) are accessible.
3340 *
3341 * Returns the 'site_url' option with the appropriate protocol, 'https' if
3342 * is_ssl() and 'http' otherwise. If $scheme is 'http' or 'https', is_ssl() is
3343 * overridden.
3344 *
3345 * @since 3.0.0
3346 *
3347 * @param string      $path   Optional. Path relative to the site URL. Default empty.
3348 * @param string|null $scheme Optional. Scheme to give the site URL context. See set_url_scheme().
3349 * @return string Site URL link with optional path appended.
3350 */
3351function site_url( $path = '', $scheme = null ) {
3352	return get_site_url( null, $path, $scheme );
3353}
3354
3355/**
3356 * Retrieves the URL for a given site where WordPress application files
3357 * (e.g. wp-blog-header.php or the wp-admin/ folder) are accessible.
3358 *
3359 * Returns the 'site_url' option with the appropriate protocol, 'https' if
3360 * is_ssl() and 'http' otherwise. If `$scheme` is 'http' or 'https',
3361 * `is_ssl()` is overridden.
3362 *
3363 * @since 3.0.0
3364 *
3365 * @param int|null    $blog_id Optional. Site ID. Default null (current site).
3366 * @param string      $path    Optional. Path relative to the site URL. Default empty.
3367 * @param string|null $scheme  Optional. Scheme to give the site URL context. Accepts
3368 *                             'http', 'https', 'login', 'login_post', 'admin', or
3369 *                             'relative'. Default null.
3370 * @return string Site URL link with optional path appended.
3371 */
3372function get_site_url( $blog_id = null, $path = '', $scheme = null ) {
3373	if ( empty( $blog_id ) || ! is_multisite() ) {
3374		$url = get_option( 'siteurl' );
3375	} else {
3376		switch_to_blog( $blog_id );
3377		$url = get_option( 'siteurl' );
3378		restore_current_blog();
3379	}
3380
3381	$url = set_url_scheme( $url, $scheme );
3382
3383	if ( $path && is_string( $path ) ) {
3384		$url .= '/' . ltrim( $path, '/' );
3385	}
3386
3387	/**
3388	 * Filters the site URL.
3389	 *
3390	 * @since 2.7.0
3391	 *
3392	 * @param string      $url     The complete site URL including scheme and path.
3393	 * @param string      $path    Path relative to the site URL. Blank string if no path is specified.
3394	 * @param string|null $scheme  Scheme to give the site URL context. Accepts 'http', 'https', 'login',
3395	 *                             'login_post', 'admin', 'relative' or null.
3396	 * @param int|null    $blog_id Site ID, or null for the current site.
3397	 */
3398	return apply_filters( 'site_url', $url, $path, $scheme, $blog_id );
3399}
3400
3401/**
3402 * Retrieves the URL to the admin area for the current site.
3403 *
3404 * @since 2.6.0
3405 *
3406 * @param string $path   Optional. Path relative to the admin URL. Default 'admin'.
3407 * @param string $scheme The scheme to use. Default is 'admin', which obeys force_ssl_admin() and is_ssl().
3408 *                       'http' or 'https' can be passed to force those schemes.
3409 * @return string Admin URL link with optional path appended.
3410 */
3411function admin_url( $path = '', $scheme = 'admin' ) {
3412	return get_admin_url( null, $path, $scheme );
3413}
3414
3415/**
3416 * Retrieves the URL to the admin area for a given site.
3417 *
3418 * @since 3.0.0
3419 *
3420 * @param int|null $blog_id Optional. Site ID. Default null (current site).
3421 * @param string   $path    Optional. Path relative to the admin URL. Default empty.
3422 * @param string   $scheme  Optional. The scheme to use. Accepts 'http' or 'https',
3423 *                          to force those schemes. Default 'admin', which obeys
3424 *                          force_ssl_admin() and is_ssl().
3425 * @return string Admin URL link with optional path appended.
3426 */
3427function get_admin_url( $blog_id = null, $path = '', $scheme = 'admin' ) {
3428	$url = get_site_url( $blog_id, 'wp-admin/', $scheme );
3429
3430	if ( $path && is_string( $path ) ) {
3431		$url .= ltrim( $path, '/' );
3432	}
3433
3434	/**
3435	 * Filters the admin area URL.
3436	 *
3437	 * @since 2.8.0
3438	 * @since 5.8.0 The `$scheme` parameter was added.
3439	 *
3440	 * @param string      $url     The complete admin area URL including scheme and path.
3441	 * @param string      $path    Path relative to the admin area URL. Blank string if no path is specified.
3442	 * @param int|null    $blog_id Site ID, or null for the current site.
3443	 * @param string|null $scheme  The scheme to use. Accepts 'http', 'https',
3444	 *                             'admin', or null. Default 'admin', which obeys force_ssl_admin() and is_ssl().
3445	 */
3446	return apply_filters( 'admin_url', $url, $path, $blog_id, $scheme );
3447}
3448
3449/**
3450 * Retrieves the URL to the includes directory.
3451 *
3452 * @since 2.6.0
3453 *
3454 * @param string      $path   Optional. Path relative to the includes URL. Default empty.
3455 * @param string|null $scheme Optional. Scheme to give the includes URL context. Accepts
3456 *                            'http', 'https', or 'relative'. Default null.
3457 * @return string Includes URL link with optional path appended.
3458 */
3459function includes_url( $path = '', $scheme = null ) {
3460	$url = site_url( '/' . WPINC . '/', $scheme );
3461
3462	if ( $path && is_string( $path ) ) {
3463		$url .= ltrim( $path, '/' );
3464	}
3465
3466	/**
3467	 * Filters the URL to the includes directory.
3468	 *
3469	 * @since 2.8.0
3470	 * @since 5.8.0 The `$scheme` parameter was added.
3471	 *
3472	 * @param string      $url    The complete URL to the includes directory including scheme and path.
3473	 * @param string      $path   Path relative to the URL to the wp-includes directory. Blank string
3474	 *                            if no path is specified.
3475	 * @param string|null $scheme Scheme to give the includes URL context. Accepts
3476	 *                            'http', 'https', 'relative', or null. Default null.
3477	 */
3478	return apply_filters( 'includes_url', $url, $path, $scheme );
3479}
3480
3481/**
3482 * Retrieves the URL to the content directory.
3483 *
3484 * @since 2.6.0
3485 *
3486 * @param string $path Optional. Path relative to the content URL. Default empty.
3487 * @return string Content URL link with optional path appended.
3488 */
3489function content_url( $path = '' ) {
3490	$url = set_url_scheme( WP_CONTENT_URL );
3491
3492	if ( $path && is_string( $path ) ) {
3493		$url .= '/' . ltrim( $path, '/' );
3494	}
3495
3496	/**
3497	 * Filters the URL to the content directory.
3498	 *
3499	 * @since 2.8.0
3500	 *
3501	 * @param string $url  The complete URL to the content directory including scheme and path.
3502	 * @param string $path Path relative to the URL to the content directory. Blank string
3503	 *                     if no path is specified.
3504	 */
3505	return apply_filters( 'content_url', $url, $path );
3506}
3507
3508/**
3509 * Retrieves a URL within the plugins or mu-plugins directory.
3510 *
3511 * Defaults to the plugins directory URL if no arguments are supplied.
3512 *
3513 * @since 2.6.0
3514 *
3515 * @param string $path   Optional. Extra path appended to the end of the URL, including
3516 *                       the relative directory if $plugin is supplied. Default empty.
3517 * @param string $plugin Optional. A full path to a file inside a plugin or mu-plugin.
3518 *                       The URL will be relative to its directory. Default empty.
3519 *                       Typically this is done by passing `__FILE__` as the argument.
3520 * @return string Plugins URL link with optional paths appended.
3521 */
3522function plugins_url( $path = '', $plugin = '' ) {
3523
3524	$path          = wp_normalize_path( $path );
3525	$plugin        = wp_normalize_path( $plugin );
3526	$mu_plugin_dir = wp_normalize_path( WPMU_PLUGIN_DIR );
3527
3528	if ( ! empty( $plugin ) && 0 === strpos( $plugin, $mu_plugin_dir ) ) {
3529		$url = WPMU_PLUGIN_URL;
3530	} else {
3531		$url = WP_PLUGIN_URL;
3532	}
3533
3534	$url = set_url_scheme( $url );
3535
3536	if ( ! empty( $plugin ) && is_string( $plugin ) ) {
3537		$folder = dirname( plugin_basename( $plugin ) );
3538		if ( '.' !== $folder ) {
3539			$url .= '/' . ltrim( $folder, '/' );
3540		}
3541	}
3542
3543	if ( $path && is_string( $path ) ) {
3544		$url .= '/' . ltrim( $path, '/' );
3545	}
3546
3547	/**
3548	 * Filters the URL to the plugins directory.
3549	 *
3550	 * @since 2.8.0
3551	 *
3552	 * @param string $url    The complete URL to the plugins directory including scheme and path.
3553	 * @param string $path   Path relative to the URL to the plugins directory. Blank string
3554	 *                       if no path is specified.
3555	 * @param string $plugin The plugin file path to be relative to. Blank string if no plugin
3556	 *                       is specified.
3557	 */
3558	return apply_filters( 'plugins_url', $url, $path, $plugin );
3559}
3560
3561/**
3562 * Retrieves the site URL for the current network.
3563 *
3564 * Returns the site URL with the appropriate protocol, 'https' if
3565 * is_ssl() and 'http' otherwise. If $scheme is 'http' or 'https', is_ssl() is
3566 * overridden.
3567 *
3568 * @since 3.0.0
3569 *
3570 * @see set_url_scheme()
3571 *
3572 * @param string      $path   Optional. Path relative to the site URL. Default empty.
3573 * @param string|null $scheme Optional. Scheme to give the site URL context. Accepts
3574 *                            'http', 'https', or 'relative'. Default null.
3575 * @return string Site URL link with optional path appended.
3576 */
3577function network_site_url( $path = '', $scheme = null ) {
3578	if ( ! is_multisite() ) {
3579		return site_url( $path, $scheme );
3580	}
3581
3582	$current_network = get_network();
3583
3584	if ( 'relative' === $scheme ) {
3585		$url = $current_network->path;
3586	} else {
3587		$url = set_url_scheme( 'http://' . $current_network->domain . $current_network->path, $scheme );
3588	}
3589
3590	if ( $path && is_string( $path ) ) {
3591		$url .= ltrim( $path, '/' );
3592	}
3593
3594	/**
3595	 * Filters the network site URL.
3596	 *
3597	 * @since 3.0.0
3598	 *
3599	 * @param string      $url    The complete network site URL including scheme and path.
3600	 * @param string      $path   Path relative to the network site URL. Blank string if
3601	 *                            no path is specified.
3602	 * @param string|null $scheme Scheme to give the URL context. Accepts 'http', 'https',
3603	 *                            'relative' or null.
3604	 */
3605	return apply_filters( 'network_site_url', $url, $path, $scheme );
3606}
3607
3608/**
3609 * Retrieves the home URL for the current network.
3610 *
3611 * Returns the home URL with the appropriate protocol, 'https' is_ssl()
3612 * and 'http' otherwise. If `$scheme` is 'http' or 'https', `is_ssl()` is
3613 * overridden.
3614 *
3615 * @since 3.0.0
3616 *
3617 * @param string      $path   Optional. Path relative to the home URL. Default empty.
3618 * @param string|null $scheme Optional. Scheme to give the home URL context. Accepts
3619 *                            'http', 'https', or 'relative'. Default null.
3620 * @return string Home URL link with optional path appended.
3621 */
3622function network_home_url( $path = '', $scheme = null ) {
3623	if ( ! is_multisite() ) {
3624		return home_url( $path, $scheme );
3625	}
3626
3627	$current_network = get_network();
3628	$orig_scheme     = $scheme;
3629
3630	if ( ! in_array( $scheme, array( 'http', 'https', 'relative' ), true ) ) {
3631		$scheme = is_ssl() ? 'https' : 'http';
3632	}
3633
3634	if ( 'relative' === $scheme ) {
3635		$url = $current_network->path;
3636	} else {
3637		$url = set_url_scheme( 'http://' . $current_network->domain . $current_network->path, $scheme );
3638	}
3639
3640	if ( $path && is_string( $path ) ) {
3641		$url .= ltrim( $path, '/' );
3642	}
3643
3644	/**
3645	 * Filters the network home URL.
3646	 *
3647	 * @since 3.0.0
3648	 *
3649	 * @param string      $url         The complete network home URL including scheme and path.
3650	 * @param string      $path        Path relative to the network home URL. Blank string
3651	 *                                 if no path is specified.
3652	 * @param string|null $orig_scheme Scheme to give the URL context. Accepts 'http', 'https',
3653	 *                                 'relative' or null.
3654	 */
3655	return apply_filters( 'network_home_url', $url, $path, $orig_scheme );
3656}
3657
3658/**
3659 * Retrieves the URL to the admin area for the network.
3660 *
3661 * @since 3.0.0
3662 *
3663 * @param string $path   Optional path relative to the admin URL. Default empty.
3664 * @param string $scheme Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3665 *                       and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3666 * @return string Admin URL link with optional path appended.
3667 */
3668function network_admin_url( $path = '', $scheme = 'admin' ) {
3669	if ( ! is_multisite() ) {
3670		return admin_url( $path, $scheme );
3671	}
3672
3673	$url = network_site_url( 'wp-admin/network/', $scheme );
3674
3675	if ( $path && is_string( $path ) ) {
3676		$url .= ltrim( $path, '/' );
3677	}
3678
3679	/**
3680	 * Filters the network admin URL.
3681	 *
3682	 * @since 3.0.0
3683	 * @since 5.8.0 The `$scheme` parameter was added.
3684	 *
3685	 * @param string      $url    The complete network admin URL including scheme and path.
3686	 * @param string      $path   Path relative to the network admin URL. Blank string if
3687	 *                            no path is specified.
3688	 * @param string|null $scheme The scheme to use. Accepts 'http', 'https',
3689	 *                            'admin', or null. Default is 'admin', which obeys force_ssl_admin() and is_ssl().
3690	 */
3691	return apply_filters( 'network_admin_url', $url, $path, $scheme );
3692}
3693
3694/**
3695 * Retrieves the URL to the admin area for the current user.
3696 *
3697 * @since 3.0.0
3698 *
3699 * @param string $path   Optional. Path relative to the admin URL. Default empty.
3700 * @param string $scheme Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3701 *                       and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3702 * @return string Admin URL link with optional path appended.
3703 */
3704function user_admin_url( $path = '', $scheme = 'admin' ) {
3705	$url = network_site_url( 'wp-admin/user/', $scheme );
3706
3707	if ( $path && is_string( $path ) ) {
3708		$url .= ltrim( $path, '/' );
3709	}
3710
3711	/**
3712	 * Filters the user admin URL for the current user.
3713	 *
3714	 * @since 3.1.0
3715	 * @since 5.8.0 The `$scheme` parameter was added.
3716	 *
3717	 * @param string      $url    The complete URL including scheme and path.
3718	 * @param string      $path   Path relative to the URL. Blank string if
3719	 *                            no path is specified.
3720	 * @param string|null $scheme The scheme to use. Accepts 'http', 'https',
3721	 *                            'admin', or null. Default is 'admin', which obeys force_ssl_admin() and is_ssl().
3722	 */
3723	return apply_filters( 'user_admin_url', $url, $path, $scheme );
3724}
3725
3726/**
3727 * Retrieves the URL to the admin area for either the current site or the network depending on context.
3728 *
3729 * @since 3.1.0
3730 *
3731 * @param string $path   Optional. Path relative to the admin URL. Default empty.
3732 * @param string $scheme Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3733 *                       and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3734 * @return string Admin URL link with optional path appended.
3735 */
3736function self_admin_url( $path = '', $scheme = 'admin' ) {
3737	if ( is_network_admin() ) {
3738		$url = network_admin_url( $path, $scheme );
3739	} elseif ( is_user_admin() ) {
3740		$url = user_admin_url( $path, $scheme );
3741	} else {
3742		$url = admin_url( $path, $scheme );
3743	}
3744
3745	/**
3746	 * Filters the admin URL for the current site or network depending on context.
3747	 *
3748	 * @since 4.9.0
3749	 *
3750	 * @param string $url    The complete URL including scheme and path.
3751	 * @param string $path   Path relative to the URL. Blank string if no path is specified.
3752	 * @param string $scheme The scheme to use.
3753	 */
3754	return apply_filters( 'self_admin_url', $url, $path, $scheme );
3755}
3756
3757/**
3758 * Sets the scheme for a URL.
3759 *
3760 * @since 3.4.0
3761 * @since 4.4.0 The 'rest' scheme was added.
3762 *
3763 * @param string      $url    Absolute URL that includes a scheme
3764 * @param string|null $scheme Optional. Scheme to give $url. Currently 'http', 'https', 'login',
3765 *                            'login_post', 'admin', 'relative', 'rest', 'rpc', or null. Default null.
3766 * @return string URL with chosen scheme.
3767 */
3768function set_url_scheme( $url, $scheme = null ) {
3769	$orig_scheme = $scheme;
3770
3771	if ( ! $scheme ) {
3772		$scheme = is_ssl() ? 'https' : 'http';
3773	} elseif ( 'admin' === $scheme || 'login' === $scheme || 'login_post' === $scheme || 'rpc' === $scheme ) {
3774		$scheme = is_ssl() || force_ssl_admin() ? 'https' : 'http';
3775	} elseif ( 'http' !== $scheme && 'https' !== $scheme && 'relative' !== $scheme ) {
3776		$scheme = is_ssl() ? 'https' : 'http';
3777	}
3778
3779	$url = trim( $url );
3780	if ( substr( $url, 0, 2 ) === '//' ) {
3781		$url = 'http:' . $url;
3782	}
3783
3784	if ( 'relative' === $scheme ) {
3785		$url = ltrim( preg_replace( '#^\w+://[^/]*#', '', $url ) );
3786		if ( '' !== $url && '/' === $url[0] ) {
3787			$url = '/' . ltrim( $url, "/ \t\n\r\0\x0B" );
3788		}
3789	} else {
3790		$url = preg_replace( '#^\w+://#', $scheme . '://', $url );
3791	}
3792
3793	/**
3794	 * Filters the resulting URL after setting the scheme.
3795	 *
3796	 * @since 3.4.0
3797	 *
3798	 * @param string      $url         The complete URL including scheme and path.
3799	 * @param string      $scheme      Scheme applied to the URL. One of 'http', 'https', or 'relative'.
3800	 * @param string|null $orig_scheme Scheme requested for the URL. One of 'http', 'https', 'login',
3801	 *                                 'login_post', 'admin', 'relative', 'rest', 'rpc', or null.
3802	 */
3803	return apply_filters( 'set_url_scheme', $url, $scheme, $orig_scheme );
3804}
3805
3806/**
3807 * Retrieves the URL to the user's dashboard.
3808 *
3809 * If a user does not belong to any site, the global user dashboard is used. If the user
3810 * belongs to the current site, the dashboard for the current site is returned. If the user
3811 * cannot edit the current site, the dashboard to the user's primary site is returned.
3812 *
3813 * @since 3.1.0
3814 *
3815 * @param int    $user_id Optional. User ID. Defaults to current user.
3816 * @param string $path    Optional path relative to the dashboard. Use only paths known to
3817 *                        both site and user admins. Default empty.
3818 * @param string $scheme  The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3819 *                        and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3820 * @return string Dashboard URL link with optional path appended.
3821 */
3822function get_dashboard_url( $user_id = 0, $path = '', $scheme = 'admin' ) {
3823	$user_id = $user_id ? (int) $user_id : get_current_user_id();
3824
3825	$blogs = get_blogs_of_user( $user_id );
3826
3827	if ( is_multisite() && ! user_can( $user_id, 'manage_network' ) && empty( $blogs ) ) {
3828		$url = user_admin_url( $path, $scheme );
3829	} elseif ( ! is_multisite() ) {
3830		$url = admin_url( $path, $scheme );
3831	} else {
3832		$current_blog = get_current_blog_id();
3833
3834		if ( $current_blog && ( user_can( $user_id, 'manage_network' ) || in_array( $current_blog, array_keys( $blogs ), true ) ) ) {
3835			$url = admin_url( $path, $scheme );
3836		} else {
3837			$active = get_active_blog_for_user( $user_id );
3838			if ( $active ) {
3839				$url = get_admin_url( $active->blog_id, $path, $scheme );
3840			} else {
3841				$url = user_admin_url( $path, $scheme );
3842			}
3843		}
3844	}
3845
3846	/**
3847	 * Filters the dashboard URL for a user.
3848	 *
3849	 * @since 3.1.0
3850	 *
3851	 * @param string $url     The complete URL including scheme and path.
3852	 * @param int    $user_id The user ID.
3853	 * @param string $path    Path relative to the URL. Blank string if no path is specified.
3854	 * @param string $scheme  Scheme to give the URL context. Accepts 'http', 'https', 'login',
3855	 *                        'login_post', 'admin', 'relative' or null.
3856	 */
3857	return apply_filters( 'user_dashboard_url', $url, $user_id, $path, $scheme );
3858}
3859
3860/**
3861 * Retrieves the URL to the user's profile editor.
3862 *
3863 * @since 3.1.0
3864 *
3865 * @param int    $user_id Optional. User ID. Defaults to current user.
3866 * @param string $scheme  Optional. The scheme to use. Default is 'admin', which obeys force_ssl_admin()
3867 *                        and is_ssl(). 'http' or 'https' can be passed to force those schemes.
3868 * @return string Dashboard URL link with optional path appended.
3869 */
3870function get_edit_profile_url( $user_id = 0, $scheme = 'admin' ) {
3871	$user_id = $user_id ? (int) $user_id : get_current_user_id();
3872
3873	if ( is_user_admin() ) {
3874		$url = user_admin_url( 'profile.php', $scheme );
3875	} elseif ( is_network_admin() ) {
3876		$url = network_admin_url( 'profile.php', $scheme );
3877	} else {
3878		$url = get_dashboard_url( $user_id, 'profile.php', $scheme );
3879	}
3880
3881	/**
3882	 * Filters the URL for a user's profile editor.
3883	 *
3884	 * @since 3.1.0
3885	 *
3886	 * @param string $url     The complete URL including scheme and path.
3887	 * @param int    $user_id The user ID.
3888	 * @param string $scheme  Scheme to give the URL context. Accepts 'http', 'https', 'login',
3889	 *                        'login_post', 'admin', 'relative' or null.
3890	 */
3891	return apply_filters( 'edit_profile_url', $url, $user_id, $scheme );
3892}
3893
3894/**
3895 * Returns the canonical URL for a post.
3896 *
3897 * When the post is the same as the current requested page the function will handle the
3898 * pagination arguments too.
3899 *
3900 * @since 4.6.0
3901 *
3902 * @param int|WP_Post $post Optional. Post ID or object. Default is global `$post`.
3903 * @return string|false The canonical URL, or false if the post does not exist or has not
3904 *                      been published yet.
3905 */
3906function wp_get_canonical_url( $post = null ) {
3907	$post = get_post( $post );
3908
3909	if ( ! $post ) {
3910		return false;
3911	}
3912
3913	if ( 'publish' !== $post->post_status ) {
3914		return false;
3915	}
3916
3917	$canonical_url = get_permalink( $post );
3918
3919	// If a canonical is being generated for the current page, make sure it has pagination if needed.
3920	if ( get_queried_object_id() === $post->ID ) {
3921		$page = get_query_var( 'page', 0 );
3922		if ( $page >= 2 ) {
3923			if ( ! get_option( 'permalink_structure' ) ) {
3924				$canonical_url = add_query_arg( 'page', $page, $canonical_url );
3925			} else {
3926				$canonical_url = trailingslashit( $canonical_url ) . user_trailingslashit( $page, 'single_paged' );
3927			}
3928		}
3929
3930		$cpage = get_query_var( 'cpage', 0 );
3931		if ( $cpage ) {
3932			$canonical_url = get_comments_pagenum_link( $cpage );
3933		}
3934	}
3935
3936	/**
3937	 * Filters the canonical URL for a post.
3938	 *
3939	 * @since 4.6.0
3940	 *
3941	 * @param string  $canonical_url The post's canonical URL.
3942	 * @param WP_Post $post          Post object.
3943	 */
3944	return apply_filters( 'get_canonical_url', $canonical_url, $post );
3945}
3946
3947/**
3948 * Outputs rel=canonical for singular queries.
3949 *
3950 * @since 2.9.0
3951 * @since 4.6.0 Adjusted to use `wp_get_canonical_url()`.
3952 */
3953function rel_canonical() {
3954	if ( ! is_singular() ) {
3955		return;
3956	}
3957
3958	$id = get_queried_object_id();
3959
3960	if ( 0 === $id ) {
3961		return;
3962	}
3963
3964	$url = wp_get_canonical_url( $id );
3965
3966	if ( ! empty( $url ) ) {
3967		echo '<link rel="canonical" href="' . esc_url( $url ) . '" />' . "\n";
3968	}
3969}
3970
3971/**
3972 * Returns a shortlink for a post, page, attachment, or site.
3973 *
3974 * This function exists to provide a shortlink tag that all themes and plugins can target.
3975 * A plugin must hook in to provide the actual shortlinks. Default shortlink support is
3976 * limited to providing ?p= style links for posts. Plugins can short-circuit this function
3977 * via the {@see 'pre_get_shortlink'} filter or filter the output via the {@see 'get_shortlink'}
3978 * filter.
3979 *
3980 * @since 3.0.0
3981 *
3982 * @param int    $id          Optional. A post or site ID. Default is 0, which means the current post or site.
3983 * @param string $context     Optional. Whether the ID is a 'site' id, 'post' id, or 'media' id. If 'post',
3984 *                            the post_type of the post is consulted. If 'query', the current query is consulted
3985 *                            to determine the ID and context. Default 'post'.
3986 * @param bool   $allow_slugs Optional. Whether to allow post slugs in the shortlink. It is up to the plugin how
3987 *                            and whether to honor this. Default true.
3988 * @return string A shortlink or an empty string if no shortlink exists for the requested resource or if shortlinks
3989 *                are not enabled.
3990 */
3991function wp_get_shortlink( $id = 0, $context = 'post', $allow_slugs = true ) {
3992	/**
3993	 * Filters whether to preempt generating a shortlink for the given post.
3994	 *
3995	 * Returning a truthy value from the filter will effectively short-circuit
3996	 * the shortlink generation process, returning that value instead.
3997	 *
3998	 * @since 3.0.0
3999	 *
4000	 * @param false|string $return      Short-circuit return value. Either false or a URL string.
4001	 * @param int          $id          Post ID, or 0 for the current post.
4002	 * @param string       $context     The context for the link. One of 'post' or 'query',
4003	 * @param bool         $allow_slugs Whether to allow post slugs in the shortlink.
4004	 */
4005	$shortlink = apply_filters( 'pre_get_shortlink', false, $id, $context, $allow_slugs );
4006
4007	if ( false !== $shortlink ) {
4008		return $shortlink;
4009	}
4010
4011	$post_id = 0;
4012	if ( 'query' === $context && is_singular() ) {
4013		$post_id = get_queried_object_id();
4014		$post    = get_post( $post_id );
4015	} elseif ( 'post' === $context ) {
4016		$post = get_post( $id );
4017		if ( ! empty( $post->ID ) ) {
4018			$post_id = $post->ID;
4019		}
4020	}
4021
4022	$shortlink = '';
4023
4024	// Return `?p=` link for all public post types.
4025	if ( ! empty( $post_id ) ) {
4026		$post_type = get_post_type_object( $post->post_type );
4027
4028		if ( 'page' === $post->post_type && get_option( 'page_on_front' ) == $post->ID && 'page' === get_option( 'show_on_front' ) ) {
4029			$shortlink = home_url( '/' );
4030		} elseif ( $post_type && $post_type->public ) {
4031			$shortlink = home_url( '?p=' . $post_id );
4032		}
4033	}
4034
4035	/**
4036	 * Filters the shortlink for a post.
4037	 *
4038	 * @since 3.0.0
4039	 *
4040	 * @param string $shortlink   Shortlink URL.
4041	 * @param int    $id          Post ID, or 0 for the current post.
4042	 * @param string $context     The context for the link. One of 'post' or 'query',
4043	 * @param bool   $allow_slugs Whether to allow post slugs in the shortlink. Not used by default.
4044	 */
4045	return apply_filters( 'get_shortlink', $shortlink, $id, $context, $allow_slugs );
4046}
4047
4048/**
4049 * Injects rel=shortlink into the head if a shortlink is defined for the current page.
4050 *
4051 * Attached to the {@see 'wp_head'} action.
4052 *
4053 * @since 3.0.0
4054 */
4055function wp_shortlink_wp_head() {
4056	$shortlink = wp_get_shortlink( 0, 'query' );
4057
4058	if ( empty( $shortlink ) ) {
4059		return;
4060	}
4061
4062	echo "<link rel='shortlink' href='" . esc_url( $shortlink ) . "' />\n";
4063}
4064
4065/**
4066 * Sends a Link: rel=shortlink header if a shortlink is defined for the current page.
4067 *
4068 * Attached to the {@see 'wp'} action.
4069 *
4070 * @since 3.0.0
4071 */
4072function wp_shortlink_header() {
4073	if ( headers_sent() ) {
4074		return;
4075	}
4076
4077	$shortlink = wp_get_shortlink( 0, 'query' );
4078
4079	if ( empty( $shortlink ) ) {
4080		return;
4081	}
4082
4083	header( 'Link: <' . $shortlink . '>; rel=shortlink', false );
4084}
4085
4086/**
4087 * Displays the shortlink for a post.
4088 *
4089 * Must be called from inside "The Loop"
4090 *
4091 * Call like the_shortlink( __( 'Shortlinkage FTW' ) )
4092 *
4093 * @since 3.0.0
4094 *
4095 * @param string $text   Optional The link text or HTML to be displayed. Defaults to 'This is the short link.'
4096 * @param string $title  Optional The tooltip for the link. Must be sanitized. Defaults to the sanitized post title.
4097 * @param string $before Optional HTML to display before the link. Default empty.
4098 * @param string $after  Optional HTML to display after the link. Default empty.
4099 */
4100function the_shortlink( $text = '', $title = '', $before = '', $after = '' ) {
4101	$post = get_post();
4102
4103	if ( empty( $text ) ) {
4104		$text = __( 'This is the short link.' );
4105	}
4106
4107	if ( empty( $title ) ) {
4108		$title = the_title_attribute( array( 'echo' => false ) );
4109	}
4110
4111	$shortlink = wp_get_shortlink( $post->ID );
4112
4113	if ( ! empty( $shortlink ) ) {
4114		$link = '<a rel="shortlink" href="' . esc_url( $shortlink ) . '" title="' . $title . '">' . $text . '</a>';
4115
4116		/**
4117		 * Filters the short link anchor tag for a post.
4118		 *
4119		 * @since 3.0.0
4120		 *
4121		 * @param string $link      Shortlink anchor tag.
4122		 * @param string $shortlink Shortlink URL.
4123		 * @param string $text      Shortlink's text.
4124		 * @param string $title     Shortlink's title attribute.
4125		 */
4126		$link = apply_filters( 'the_shortlink', $link, $shortlink, $text, $title );
4127		echo $before, $link, $after;
4128	}
4129}
4130
4131
4132/**
4133 * Retrieves the avatar URL.
4134 *
4135 * @since 4.2.0
4136 *
4137 * @param mixed $id_or_email The Gravatar to retrieve a URL for. Accepts a user_id, gravatar md5 hash,
4138 *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4139 * @param array $args {
4140 *     Optional. Arguments to return instead of the default arguments.
4141 *
4142 *     @type int    $size           Height and width of the avatar in pixels. Default 96.
4143 *     @type string $default        URL for the default image or a default type. Accepts '404' (return
4144 *                                  a 404 instead of a default image), 'retro' (8bit), 'monsterid' (monster),
4145 *                                  'wavatar' (cartoon face), 'indenticon' (the "quilt"), 'mystery', 'mm',
4146 *                                  or 'mysteryman' (The Oyster Man), 'blank' (transparent GIF), or
4147 *                                  'gravatar_default' (the Gravatar logo). Default is the value of the
4148 *                                  'avatar_default' option, with a fallback of 'mystery'.
4149 *     @type bool   $force_default  Whether to always show the default image, never the Gravatar. Default false.
4150 *     @type string $rating         What rating to display avatars up to. Accepts 'G', 'PG', 'R', 'X', and are
4151 *                                  judged in that order. Default is the value of the 'avatar_rating' option.
4152 *     @type string $scheme         URL scheme to use. See set_url_scheme() for accepted values.
4153 *                                  Default null.
4154 *     @type array  $processed_args When the function returns, the value will be the processed/sanitized $args
4155 *                                  plus a "found_avatar" guess. Pass as a reference. Default null.
4156 * }
4157 * @return string|false The URL of the avatar on success, false on failure.
4158 */
4159function get_avatar_url( $id_or_email, $args = null ) {
4160	$args = get_avatar_data( $id_or_email, $args );
4161	return $args['url'];
4162}
4163
4164
4165/**
4166 * Check if this comment type allows avatars to be retrieved.
4167 *
4168 * @since 5.1.0
4169 *
4170 * @param string $comment_type Comment type to check.
4171 * @return bool Whether the comment type is allowed for retrieving avatars.
4172 */
4173function is_avatar_comment_type( $comment_type ) {
4174	/**
4175	 * Filters the list of allowed comment types for retrieving avatars.
4176	 *
4177	 * @since 3.0.0
4178	 *
4179	 * @param array $types An array of content types. Default only contains 'comment'.
4180	 */
4181	$allowed_comment_types = apply_filters( 'get_avatar_comment_types', array( 'comment' ) );
4182
4183	return in_array( $comment_type, (array) $allowed_comment_types, true );
4184}
4185
4186
4187/**
4188 * Retrieves default data about the avatar.
4189 *
4190 * @since 4.2.0
4191 *
4192 * @param mixed $id_or_email The Gravatar to retrieve. Accepts a user ID, Gravatar MD5 hash,
4193 *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4194 * @param array $args {
4195 *     Optional. Arguments to return instead of the default arguments.
4196 *
4197 *     @type int    $size           Height and width of the avatar image file in pixels. Default 96.
4198 *     @type int    $height         Display height of the avatar in pixels. Defaults to $size.
4199 *     @type int    $width          Display width of the avatar in pixels. Defaults to $size.
4200 *     @type string $default        URL for the default image or a default type. Accepts '404' (return
4201 *                                  a 404 instead of a default image), 'retro' (8bit), 'monsterid' (monster),
4202 *                                  'wavatar' (cartoon face), 'indenticon' (the "quilt"), 'mystery', 'mm',
4203 *                                  or 'mysteryman' (The Oyster Man), 'blank' (transparent GIF), or
4204 *                                  'gravatar_default' (the Gravatar logo). Default is the value of the
4205 *                                  'avatar_default' option, with a fallback of 'mystery'.
4206 *     @type bool   $force_default  Whether to always show the default image, never the Gravatar. Default false.
4207 *     @type string $rating         What rating to display avatars up to. Accepts 'G', 'PG', 'R', 'X', and are
4208 *                                  judged in that order. Default is the value of the 'avatar_rating' option.
4209 *     @type string $scheme         URL scheme to use. See set_url_scheme() for accepted values.
4210 *                                  Default null.
4211 *     @type array  $processed_args When the function returns, the value will be the processed/sanitized $args
4212 *                                  plus a "found_avatar" guess. Pass as a reference. Default null.
4213 *     @type string $extra_attr     HTML attributes to insert in the IMG element. Is not sanitized. Default empty.
4214 * }
4215 * @return array {
4216 *     Along with the arguments passed in `$args`, this will contain a couple of extra arguments.
4217 *
4218 *     @type bool   $found_avatar True if we were able to find an avatar for this user,
4219 *                                false or not set if we couldn't.
4220 *     @type string $url          The URL of the avatar we found.
4221 * }
4222 */
4223function get_avatar_data( $id_or_email, $args = null ) {
4224	$args = wp_parse_args(
4225		$args,
4226		array(
4227			'size'           => 96,
4228			'height'         => null,
4229			'width'          => null,
4230			'default'        => get_option( 'avatar_default', 'mystery' ),
4231			'force_default'  => false,
4232			'rating'         => get_option( 'avatar_rating' ),
4233			'scheme'         => null,
4234			'processed_args' => null, // If used, should be a reference.
4235			'extra_attr'     => '',
4236		)
4237	);
4238
4239	if ( is_numeric( $args['size'] ) ) {
4240		$args['size'] = absint( $args['size'] );
4241		if ( ! $args['size'] ) {
4242			$args['size'] = 96;
4243		}
4244	} else {
4245		$args['size'] = 96;
4246	}
4247
4248	if ( is_numeric( $args['height'] ) ) {
4249		$args['height'] = absint( $args['height'] );
4250		if ( ! $args['height'] ) {
4251			$args['height'] = $args['size'];
4252		}
4253	} else {
4254		$args['height'] = $args['size'];
4255	}
4256
4257	if ( is_numeric( $args['width'] ) ) {
4258		$args['width'] = absint( $args['width'] );
4259		if ( ! $args['width'] ) {
4260			$args['width'] = $args['size'];
4261		}
4262	} else {
4263		$args['width'] = $args['size'];
4264	}
4265
4266	if ( empty( $args['default'] ) ) {
4267		$args['default'] = get_option( 'avatar_default', 'mystery' );
4268	}
4269
4270	switch ( $args['default'] ) {
4271		case 'mm':
4272		case 'mystery':
4273		case 'mysteryman':
4274			$args['default'] = 'mm';
4275			break;
4276		case 'gravatar_default':
4277			$args['default'] = false;
4278			break;
4279	}
4280
4281	$args['force_default'] = (bool) $args['force_default'];
4282
4283	$args['rating'] = strtolower( $args['rating'] );
4284
4285	$args['found_avatar'] = false;
4286
4287	/**
4288	 * Filters whether to retrieve the avatar URL early.
4289	 *
4290	 * Passing a non-null value in the 'url' member of the return array will
4291	 * effectively short circuit get_avatar_data(), passing the value through
4292	 * the {@see 'get_avatar_data'} filter and returning early.
4293	 *
4294	 * @since 4.2.0
4295	 *
4296	 * @param array $args        Arguments passed to get_avatar_data(), after processing.
4297	 * @param mixed $id_or_email The Gravatar to retrieve. Accepts a user ID, Gravatar MD5 hash,
4298	 *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4299	 */
4300	$args = apply_filters( 'pre_get_avatar_data', $args, $id_or_email );
4301
4302	if ( isset( $args['url'] ) ) {
4303		/** This filter is documented in wp-includes/link-template.php */
4304		return apply_filters( 'get_avatar_data', $args, $id_or_email );
4305	}
4306
4307	$email_hash = '';
4308	$user       = false;
4309	$email      = false;
4310
4311	if ( is_object( $id_or_email ) && isset( $id_or_email->comment_ID ) ) {
4312		$id_or_email = get_comment( $id_or_email );
4313	}
4314
4315	// Process the user identifier.
4316	if ( is_numeric( $id_or_email ) ) {
4317		$user = get_user_by( 'id', absint( $id_or_email ) );
4318	} elseif ( is_string( $id_or_email ) ) {
4319		if ( strpos( $id_or_email, '@md5.gravatar.com' ) ) {
4320			// MD5 hash.
4321			list( $email_hash ) = explode( '@', $id_or_email );
4322		} else {
4323			// Email address.
4324			$email = $id_or_email;
4325		}
4326	} elseif ( $id_or_email instanceof WP_User ) {
4327		// User object.
4328		$user = $id_or_email;
4329	} elseif ( $id_or_email instanceof WP_Post ) {
4330		// Post object.
4331		$user = get_user_by( 'id', (int) $id_or_email->post_author );
4332	} elseif ( $id_or_email instanceof WP_Comment ) {
4333		if ( ! is_avatar_comment_type( get_comment_type( $id_or_email ) ) ) {
4334			$args['url'] = false;
4335			/** This filter is documented in wp-includes/link-template.php */
4336			return apply_filters( 'get_avatar_data', $args, $id_or_email );
4337		}
4338
4339		if ( ! empty( $id_or_email->user_id ) ) {
4340			$user = get_user_by( 'id', (int) $id_or_email->user_id );
4341		}
4342		if ( ( ! $user || is_wp_error( $user ) ) && ! empty( $id_or_email->comment_author_email ) ) {
4343			$email = $id_or_email->comment_author_email;
4344		}
4345	}
4346
4347	if ( ! $email_hash ) {
4348		if ( $user ) {
4349			$email = $user->user_email;
4350		}
4351
4352		if ( $email ) {
4353			$email_hash = md5( strtolower( trim( $email ) ) );
4354		}
4355	}
4356
4357	if ( $email_hash ) {
4358		$args['found_avatar'] = true;
4359		$gravatar_server      = hexdec( $email_hash[0] ) % 3;
4360	} else {
4361		$gravatar_server = rand( 0, 2 );
4362	}
4363
4364	$url_args = array(
4365		's' => $args['size'],
4366		'd' => $args['default'],
4367		'f' => $args['force_default'] ? 'y' : false,
4368		'r' => $args['rating'],
4369	);
4370
4371	if ( is_ssl() ) {
4372		$url = 'https://secure.gravatar.com/avatar/' . $email_hash;
4373	} else {
4374		$url = sprintf( 'http://%d.gravatar.com/avatar/%s', $gravatar_server, $email_hash );
4375	}
4376
4377	$url = add_query_arg(
4378		rawurlencode_deep( array_filter( $url_args ) ),
4379		set_url_scheme( $url, $args['scheme'] )
4380	);
4381
4382	/**
4383	 * Filters the avatar URL.
4384	 *
4385	 * @since 4.2.0
4386	 *
4387	 * @param string $url         The URL of the avatar.
4388	 * @param mixed  $id_or_email The Gravatar to retrieve. Accepts a user ID, Gravatar MD5 hash,
4389	 *                            user email, WP_User object, WP_Post object, or WP_Comment object.
4390	 * @param array  $args        Arguments passed to get_avatar_data(), after processing.
4391	 */
4392	$args['url'] = apply_filters( 'get_avatar_url', $url, $id_or_email, $args );
4393
4394	/**
4395	 * Filters the avatar data.
4396	 *
4397	 * @since 4.2.0
4398	 *
4399	 * @param array $args        Arguments passed to get_avatar_data(), after processing.
4400	 * @param mixed $id_or_email The Gravatar to retrieve. Accepts a user ID, Gravatar MD5 hash,
4401	 *                           user email, WP_User object, WP_Post object, or WP_Comment object.
4402	 */
4403	return apply_filters( 'get_avatar_data', $args, $id_or_email );
4404}
4405
4406/**
4407 * Retrieves the URL of a file in the theme.
4408 *
4409 * Searches in the stylesheet directory before the template directory so themes
4410 * which inherit from a parent theme can just override one file.
4411 *
4412 * @since 4.7.0
4413 *
4414 * @param string $file Optional. File to search for in the stylesheet directory.
4415 * @return string The URL of the file.
4416 */
4417function get_theme_file_uri( $file = '' ) {
4418	$file = ltrim( $file, '/' );
4419
4420	if ( empty( $file ) ) {
4421		$url = get_stylesheet_directory_uri();
4422	} elseif ( file_exists( get_stylesheet_directory() . '/' . $file ) ) {
4423		$url = get_stylesheet_directory_uri() . '/' . $file;
4424	} else {
4425		$url = get_template_directory_uri() . '/' . $file;
4426	}
4427
4428	/**
4429	 * Filters the URL to a file in the theme.
4430	 *
4431	 * @since 4.7.0
4432	 *
4433	 * @param string $url  The file URL.
4434	 * @param string $file The requested file to search for.
4435	 */
4436	return apply_filters( 'theme_file_uri', $url, $file );
4437}
4438
4439/**
4440 * Retrieves the URL of a file in the parent theme.
4441 *
4442 * @since 4.7.0
4443 *
4444 * @param string $file Optional. File to return the URL for in the template directory.
4445 * @return string The URL of the file.
4446 */
4447function get_parent_theme_file_uri( $file = '' ) {
4448	$file = ltrim( $file, '/' );
4449
4450	if ( empty( $file ) ) {
4451		$url = get_template_directory_uri();
4452	} else {
4453		$url = get_template_directory_uri() . '/' . $file;
4454	}
4455
4456	/**
4457	 * Filters the URL to a file in the parent theme.
4458	 *
4459	 * @since 4.7.0
4460	 *
4461	 * @param string $url  The file URL.
4462	 * @param string $file The requested file to search for.
4463	 */
4464	return apply_filters( 'parent_theme_file_uri', $url, $file );
4465}
4466
4467/**
4468 * Retrieves the path of a file in the theme.
4469 *
4470 * Searches in the stylesheet directory before the template directory so themes
4471 * which inherit from a parent theme can just override one file.
4472 *
4473 * @since 4.7.0
4474 *
4475 * @param string $file Optional. File to search for in the stylesheet directory.
4476 * @return string The path of the file.
4477 */
4478function get_theme_file_path( $file = '' ) {
4479	$file = ltrim( $file, '/' );
4480
4481	if ( empty( $file ) ) {
4482		$path = get_stylesheet_directory();
4483	} elseif ( file_exists( get_stylesheet_directory() . '/' . $file ) ) {
4484		$path = get_stylesheet_directory() . '/' . $file;
4485	} else {
4486		$path = get_template_directory() . '/' . $file;
4487	}
4488
4489	/**
4490	 * Filters the path to a file in the theme.
4491	 *
4492	 * @since 4.7.0
4493	 *
4494	 * @param string $path The file path.
4495	 * @param string $file The requested file to search for.
4496	 */
4497	return apply_filters( 'theme_file_path', $path, $file );
4498}
4499
4500/**
4501 * Retrieves the path of a file in the parent theme.
4502 *
4503 * @since 4.7.0
4504 *
4505 * @param string $file Optional. File to return the path for in the template directory.
4506 * @return string The path of the file.
4507 */
4508function get_parent_theme_file_path( $file = '' ) {
4509	$file = ltrim( $file, '/' );
4510
4511	if ( empty( $file ) ) {
4512		$path = get_template_directory();
4513	} else {
4514		$path = get_template_directory() . '/' . $file;
4515	}
4516
4517	/**
4518	 * Filters the path to a file in the parent theme.
4519	 *
4520	 * @since 4.7.0
4521	 *
4522	 * @param string $path The file path.
4523	 * @param string $file The requested file to search for.
4524	 */
4525	return apply_filters( 'parent_theme_file_path', $path, $file );
4526}
4527
4528/**
4529 * Retrieves the URL to the privacy policy page.
4530 *
4531 * @since 4.9.6
4532 *
4533 * @return string The URL to the privacy policy page. Empty string if it doesn't exist.
4534 */
4535function get_privacy_policy_url() {
4536	$url            = '';
4537	$policy_page_id = (int) get_option( 'wp_page_for_privacy_policy' );
4538
4539	if ( ! empty( $policy_page_id ) && get_post_status( $policy_page_id ) === 'publish' ) {
4540		$url = (string) get_permalink( $policy_page_id );
4541	}
4542
4543	/**
4544	 * Filters the URL of the privacy policy page.
4545	 *
4546	 * @since 4.9.6
4547	 *
4548	 * @param string $url            The URL to the privacy policy page. Empty string
4549	 *                               if it doesn't exist.
4550	 * @param int    $policy_page_id The ID of privacy policy page.
4551	 */
4552	return apply_filters( 'privacy_policy_url', $url, $policy_page_id );
4553}
4554
4555/**
4556 * Displays the privacy policy link with formatting, when applicable.
4557 *
4558 * @since 4.9.6
4559 *
4560 * @param string $before Optional. Display before privacy policy link. Default empty.
4561 * @param string $after  Optional. Display after privacy policy link. Default empty.
4562 */
4563function the_privacy_policy_link( $before = '', $after = '' ) {
4564	echo get_the_privacy_policy_link( $before, $after );
4565}
4566
4567/**
4568 * Returns the privacy policy link with formatting, when applicable.
4569 *
4570 * @since 4.9.6
4571 *
4572 * @param string $before Optional. Display before privacy policy link. Default empty.
4573 * @param string $after  Optional. Display after privacy policy link. Default empty.
4574 * @return string Markup for the link and surrounding elements. Empty string if it
4575 *                doesn't exist.
4576 */
4577function get_the_privacy_policy_link( $before = '', $after = '' ) {
4578	$link               = '';
4579	$privacy_policy_url = get_privacy_policy_url();
4580	$policy_page_id     = (int) get_option( 'wp_page_for_privacy_policy' );
4581	$page_title         = ( $policy_page_id ) ? get_the_title( $policy_page_id ) : '';
4582
4583	if ( $privacy_policy_url && $page_title ) {
4584		$link = sprintf(
4585			'<a class="privacy-policy-link" href="%s">%s</a>',
4586			esc_url( $privacy_policy_url ),
4587			esc_html( $page_title )
4588		);
4589	}
4590
4591	/**
4592	 * Filters the privacy policy link.
4593	 *
4594	 * @since 4.9.6
4595	 *
4596	 * @param string $link               The privacy policy link. Empty string if it
4597	 *                                   doesn't exist.
4598	 * @param string $privacy_policy_url The URL of the privacy policy. Empty string
4599	 *                                   if it doesn't exist.
4600	 */
4601	$link = apply_filters( 'the_privacy_policy_link', $link, $privacy_policy_url );
4602
4603	if ( $link ) {
4604		return $before . $link . $after;
4605	}
4606
4607	return '';
4608}
4609