class-wpseo-replace-vars.php — Yoast SEO – Advanced SEO with real-time guidance and built-in AI 20.12

wordpress-seo / inc / class-wpseo-replace-vars.php

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class-wpseo-replace-vars.php

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1	<?php
2	/**
3	* WPSEO plugin file.
4	*
5	* @package WPSEO\Internals
6	* @since 1.5.4
7	*/
8
9	// Avoid direct calls to this file.
10	if ( ! defined( 'WPSEO_VERSION' ) ) {
11	header( 'Status: 403 Forbidden' );
12	header( 'HTTP/1.1 403 Forbidden' );
13	exit();
14	}
15
16	/**
17	* Class: WPSEO_Replace_Vars.
18	*
19	* This class implements the replacing of `%%variable_placeholders%%` with their real value based on the current
20	* requested page/post/cpt/etc in text strings.
21	*/
22	class WPSEO_Replace_Vars {
23
24	/**
25	* Default post/page/cpt information.
26	*
27	* @var array
28	*/
29	protected $defaults = [
30	'ID' => '',
31	'name' => '',
32	'post_author' => '',
33	'post_content' => '',
34	'post_date' => '',
35	'post_excerpt' => '',
36	'post_modified' => '',
37	'post_title' => '',
38	'taxonomy' => '',
39	'term_id' => '',
40	'term404' => '',
41	];
42
43	/**
44	* Current post/page/cpt information.
45	*
46	* @var stdClass
47	*/
48	protected $args;
49
50	/**
51	* Help texts for use in WPSEO -> Search appearance tabs.
52	*
53	* @var array
54	*/
55	protected static $help_texts = [];
56
57	/**
58	* Register of additional variable replacements registered by other plugins/themes.
59	*
60	* @var array
61	*/
62	protected static $external_replacements = [];
63
64	/**
65	* Setup the help texts and external replacements as statics so they will be available to all instances.
66	*/
67	public static function setup_statics_once() {
68	if ( self::$help_texts === [] ) {
69	self::set_basic_help_texts();
70	self::set_advanced_help_texts();
71	}
72
73	if ( self::$external_replacements === [] ) {
74	/**
75	* Action: 'wpseo_register_extra_replacements' - Allows for registration of additional
76	* variables to replace.
77	*/
78	do_action( 'wpseo_register_extra_replacements' );
79	}
80	}
81
82	/**
83	* Register new replacement %%variables%%.
84	* For use by other plugins/themes to register extra variables.
85	*
86	* @see wpseo_register_var_replacement() for a usage example.
87	*
88	* @param string $var_to_replace The name of the variable to replace, i.e. '%%var%%'.
89	* Note: the surrounding %% are optional.
90	* @param mixed $replace_function Function or method to call to retrieve the replacement value for the variable.
91	* Uses the same format as add_filter/add_action function parameter and
92	* should return the replacement value. DON'T echo it.
93	* @param string $type Type of variable: 'basic' or 'advanced', defaults to 'advanced'.
94	* @param string $help_text Help text to be added to the help tab for this variable.
95	*
96	* @return bool Whether the replacement function was succesfully registered.
97	*/
98	public static function register_replacement( $var_to_replace, $replace_function, $type = 'advanced', $help_text = '' ) {
99	$success = false;
100
101	if ( is_string( $var_to_replace ) && $var_to_replace !== '' ) {
102	$var_to_replace = self::remove_var_delimiter( $var_to_replace );
103
104	if ( preg_match( '`^[A-Z0-9_-]+$`i', $var_to_replace ) === false ) {
105	trigger_error( esc_html__( 'A replacement variable can only contain alphanumeric characters, an underscore or a dash. Try renaming your variable.', 'wordpress-seo' ), E_USER_WARNING );
106	}
107	elseif ( strpos( $var_to_replace, 'cf_' ) === 0 \|\| strpos( $var_to_replace, 'ct_' ) === 0 ) {
108	trigger_error( esc_html__( 'A replacement variable can not start with "%%cf_" or "%%ct_" as these are reserved for the WPSEO standard variable variables for custom fields and custom taxonomies. Try making your variable name unique.', 'wordpress-seo' ), E_USER_WARNING );
109	}
110	elseif ( ! method_exists( __CLASS__, 'retrieve_' . $var_to_replace ) ) {
111	if ( $var_to_replace !== '' && ! isset( self::$external_replacements[ $var_to_replace ] ) ) {
112	self::$external_replacements[ $var_to_replace ] = $replace_function;
113	$replacement_variable = new WPSEO_Replacement_Variable( $var_to_replace, $var_to_replace, $help_text );
114	self::register_help_text( $type, $replacement_variable );
115	$success = true;
116	}
117	else {
118	trigger_error( esc_html__( 'A replacement variable with the same name has already been registered. Try making your variable name unique.', 'wordpress-seo' ), E_USER_WARNING );
119	}
120	}
121	else {
122	trigger_error( esc_html__( 'You cannot overrule a WPSEO standard variable replacement by registering a variable with the same name. Use the "wpseo_replacements" filter instead to adjust the replacement value.', 'wordpress-seo' ), E_USER_WARNING );
123	}
124	}
125
126	return $success;
127	}
128
129	/**
130	* Replace `%%variable_placeholders%%` with their real value based on the current requested page/post/cpt/etc.
131	*
132	* @param string $text The string to replace the variables in.
133	* @param array $args The object some of the replacement values might come from,
134	* could be a post, taxonomy or term.
135	* @param array $omit Variables that should not be replaced by this function.
136	*
137	* @return string
138	*/
139	public function replace( $text, $args, $omit = [] ) {
140
141	$text = wp_strip_all_tags( $text );
142
143	// Let's see if we can bail super early.
144	if ( strpos( $text, '%%' ) === false ) {
145	return YoastSEO()->helpers->string->standardize_whitespace( $text );
146	}
147
148	$args = (array) $args;
149	if ( isset( $args['post_content'] ) && ! empty( $args['post_content'] ) ) {
150	$args['post_content'] = YoastSEO()->helpers->string->strip_shortcode( $args['post_content'] );
151	}
152	if ( isset( $args['post_excerpt'] ) && ! empty( $args['post_excerpt'] ) ) {
153	$args['post_excerpt'] = YoastSEO()->helpers->string->strip_shortcode( $args['post_excerpt'] );
154	}
155	$this->args = (object) wp_parse_args( $args, $this->defaults );
156
157	// Clean $omit array.
158	if ( is_array( $omit ) && $omit !== [] ) {
159	$omit = array_map( [ __CLASS__, 'remove_var_delimiter' ], $omit );
160	}
161
162	$replacements = [];
163	if ( preg_match_all( '`%%([^%]+(%%single)?)%%?`iu', $text, $matches ) ) {
164	$replacements = $this->set_up_replacements( $matches, $omit );
165	}
166
167	/**
168	* Filter: 'wpseo_replacements' - Allow customization of the replacements before they are applied.
169	*
170	* @api array $replacements The replacements.
171	*
172	* @param array $args The object some of the replacement values might come from,
173	* could be a post, taxonomy or term.
174	*/
175	$replacements = apply_filters( 'wpseo_replacements', $replacements, $this->args );
176
177	// Do the actual replacements.
178	if ( is_array( $replacements ) && $replacements !== [] ) {
179	$text = str_replace(
180	array_keys( $replacements ),
181	// Make sure to exclude replacement values that are arrays e.g. coming from a custom field serialized value.
182	array_filter( array_values( $replacements ), 'is_scalar' ),
183	$text
184	);
185	}
186
187	/**
188	* Filter: 'wpseo_replacements_final' - Allow overruling of whether or not to remove placeholders
189	* which didn't yield a replacement.
190	*
191	* @example <code>add_filter( 'wpseo_replacements_final', '__return_false' );</code>
192	*
193	* @api bool $final
194	*/
195	if ( apply_filters( 'wpseo_replacements_final', true ) === true && ( isset( $matches[1] ) && is_array( $matches[1] ) ) ) {
196	// Remove non-replaced variables.
197	$remove = array_diff( $matches[1], $omit ); // Make sure the $omit variables do not get removed.
198	$remove = array_map( [ __CLASS__, 'add_var_delimiter' ], $remove );
199	$text = str_replace( $remove, '', $text );
200	}
201
202	// Undouble separators which have nothing between them, i.e. where a non-replaced variable was removed.
203	if ( isset( $replacements['%%sep%%'] ) && ( is_string( $replacements['%%sep%%'] ) && $replacements['%%sep%%'] !== '' ) ) {
204	$q_sep = preg_quote( $replacements['%%sep%%'], '`' );
205	$text = preg_replace( '`' . $q_sep . '(?:\s' . $q_sep . ')`u', $replacements['%%sep%%'], $text );
206	}
207
208	// Remove superfluous whitespace.
209	$text = YoastSEO()->helpers->string->standardize_whitespace( $text );
210
211	return $text;
212	}
213
214	/**
215	* Register a new replacement variable if it has not been registered already.
216	*
217	* @param string $var_to_replace The name of the variable to replace, i.e. '%%var%%'.
218	* Note: the surrounding %% are optional.
219	* @param mixed $replace_function Function or method to call to retrieve the replacement value for the variable.
220	* Uses the same format as add_filter/add_action function parameter and
221	* should return the replacement value. DON'T echo it.
222	* @param string $type Type of variable: 'basic' or 'advanced', defaults to 'advanced'.
223	* @param string $help_text Help text to be added to the help tab for this variable.
224	*
225	* @return bool `true` if the replace var has been registered, `false` if not.
226	*/
227	public function safe_register_replacement( $var_to_replace, $replace_function, $type = 'advanced', $help_text = '' ) {
228	if ( ! $this->has_been_registered( $var_to_replace ) ) {
229	return self::register_replacement( $var_to_replace, $replace_function, $type, $help_text );
230	}
231	return false;
232	}
233
234	/**
235	* Checks whether the given replacement variable has already been registered or not.
236	*
237	* @param string $replacement_variable The replacement variable to check, including the variable delimiter (e.g. `%%var%%`).
238	*
239	* @return bool `true` if the replacement variable has already been registered.
240	*/
241	public function has_been_registered( $replacement_variable ) {
242	$replacement_variable = self::remove_var_delimiter( $replacement_variable );
243
244	return isset( self::$external_replacements[ $replacement_variable ] );
245	}
246
247	/**
248	* Returns the list of hidden replace vars.
249	*
250	* E.g. the replace vars that should work, but are not advertised.
251	*
252	* @return string[] The list of hidden replace vars.
253	*/
254	public function get_hidden_replace_vars() {
255	return [
256	'currentdate',
257	'currentyear',
258	'currentmonth',
259	'currentday',
260	'post_year',
261	'post_month',
262	'post_day',
263	'author_first_name',
264	'author_last_name',
265	'permalink',
266	'post_content',
267	'category_title',
268	];
269	}
270
271	/**
272	* Retrieve the replacements for the variables found.
273	*
274	* @param array $matches Variables found in the original string - regex result.
275	* @param array $omit Variables that should not be replaced by this function.
276	*
277	* @return array Retrieved replacements - this might be a smaller array as some variables
278	* may not yield a replacement in certain contexts.
279	*/
280	private function set_up_replacements( $matches, $omit ) {
281
282	$replacements = [];
283
284	// @todo Figure out a way to deal with external functions starting with cf_/ct_.
285	foreach ( $matches[1] as $k => $var ) {
286
287	// Don't set up replacements which should be omitted.
288	if ( in_array( $var, $omit, true ) ) {
289	continue;
290	}
291
292	// Deal with variable variable names first.
293	if ( strpos( $var, 'cf_' ) === 0 ) {
294	$replacement = $this->retrieve_cf_custom_field_name( $var );
295	}
296	elseif ( strpos( $var, 'ct_desc_' ) === 0 ) {
297	$replacement = $this->retrieve_ct_desc_custom_tax_name( $var );
298	}
299	elseif ( strpos( $var, 'ct_' ) === 0 ) {
300	$single = ( isset( $matches[2][ $k ] ) && $matches[2][ $k ] !== '' );
301	$replacement = $this->retrieve_ct_custom_tax_name( $var, $single );
302	}
303	// Deal with non-variable variable names.
304	elseif ( method_exists( $this, 'retrieve_' . $var ) ) {
305	$method_name = 'retrieve_' . $var;
306	$replacement = $this->$method_name();
307	}
308	// Deal with externally defined variable names.
309	elseif ( isset( self::$external_replacements[ $var ] ) && ! is_null( self::$external_replacements[ $var ] ) ) {
310	$replacement = call_user_func( self::$external_replacements[ $var ], $var, $this->args );
311	}
312
313	// Replacement retrievals can return null if no replacement can be determined, root those outs.
314	if ( isset( $replacement ) ) {
315	$var = self::add_var_delimiter( $var );
316	$replacements[ $var ] = $replacement;
317	}
318	unset( $replacement, $single, $method_name );
319	}
320
321	return $replacements;
322	}
323
324	/* ********************* BASIC VARIABLES ************************ */
325
326	/**
327	* Retrieve the post/cpt categories (comma separated) for use as replacement string.
328	*
329	* @return string\|null
330	*/
331	private function retrieve_category() {
332	$replacement = null;
333
334	if ( ! empty( $this->args->ID ) ) {
335	$cat = $this->get_terms( $this->args->ID, 'category' );
336	if ( $cat !== '' ) {
337	return $cat;
338	}
339	}
340
341	if ( isset( $this->args->cat_name ) && ! empty( $this->args->cat_name ) ) {
342	$replacement = $this->args->cat_name;
343	}
344
345	return $replacement;
346	}
347
348	/**
349	* Retrieve the category description for use as replacement string.
350	*
351	* @return string\|null
352	*/
353	private function retrieve_category_description() {
354	return $this->retrieve_term_description();
355	}
356
357	/**
358	* Retrieve the date of the post/page/cpt for use as replacement string.
359	*
360	* @return string\|null
361	*/
362	private function retrieve_date() {
363	$replacement = null;
364
365	if ( $this->args->post_date !== '' ) {
366	// Returns a string.
367	$replacement = YoastSEO()->helpers->date->format_translated( $this->args->post_date, get_option( 'date_format' ) );
368	}
369	else {
370	if ( get_query_var( 'day' ) && get_query_var( 'day' ) !== '' ) {
371	// Returns a string.
372	$replacement = get_the_date();
373	}
374	else {
375	if ( single_month_title( ' ', false ) && single_month_title( ' ', false ) !== '' ) {
376	// Returns a string.
377	$replacement = single_month_title( ' ', false );
378	}
379	elseif ( get_query_var( 'year' ) !== '' ) {
380	// Returns an integer, let's cast to string.
381	$replacement = (string) get_query_var( 'year' );
382	}
383	}
384	}
385
386	return $replacement;
387	}
388
389	/**
390	* Retrieve the post/page/cpt excerpt for use as replacement string.
391	* The excerpt will be auto-generated if it does not exist.
392	*
393	* @return string\|null
394	*/
395	private function retrieve_excerpt() {
396	$replacement = null;
397	$locale = \get_locale();
398
399	// Japanese doesn't have a jp_JP variant in WP.
400	$limit = ( $locale === 'ja' ) ? 80 : 156;
401
402	// The check `post_password_required` is because excerpt must be hidden for a post with a password.
403	if ( ! empty( $this->args->ID ) && ! post_password_required( $this->args->ID ) ) {
404	if ( $this->args->post_excerpt !== '' ) {
405	$replacement = wp_strip_all_tags( $this->args->post_excerpt );
406	}
407	elseif ( $this->args->post_content !== '' ) {
408	$content = strip_shortcodes( $this->args->post_content );
409	$content = wp_strip_all_tags( $content );
410
411	if ( mb_strlen( $content ) <= $limit ) {
412	return $content;
413	}
414
415	$replacement = wp_html_excerpt( $content, $limit );
416
417	// Check if the description has space and trim the auto-generated string to a word boundary.
418	if ( strrpos( $replacement, ' ' ) ) {
419	$replacement = substr( $replacement, 0, strrpos( $replacement, ' ' ) );
420	}
421	}
422	}
423
424	return $replacement;
425	}
426
427	/**
428	* Retrieve the post/page/cpt excerpt for use as replacement string (without auto-generation).
429	*
430	* @return string\|null
431	*/
432	private function retrieve_excerpt_only() {
433	$replacement = null;
434
435	// The check `post_password_required` is because excerpt must be hidden for a post with a password.
436	if ( ! empty( $this->args->ID ) && $this->args->post_excerpt !== '' && ! post_password_required( $this->args->ID ) ) {
437	$replacement = wp_strip_all_tags( $this->args->post_excerpt );
438	}
439
440	return $replacement;
441	}
442
443	/**
444	* Retrieve the title of the parent page of the current page/cpt for use as replacement string.
445	* Only applicable for hierarchical post types.
446	*
447	* @todo Check: shouldn't this use $this->args as well ?
448	*
449	* @return string\|null
450	*/
451	private function retrieve_parent_title() {
452	$replacement = null;
453
454	if ( ! empty( $this->args->ID ) ) {
455	$parent_id = wp_get_post_parent_id( $this->args->ID );
456	if ( $parent_id ) {
457	$replacement = get_the_title( $parent_id );
458	}
459	}
460
461	return $replacement;
462	}
463
464	/**
465	* Retrieve the current search phrase for use as replacement string.
466	*
467	* @return string\|null
468	*/
469	private function retrieve_searchphrase() {
470	$replacement = null;
471
472	$search = get_query_var( 's' );
473	if ( $search !== '' ) {
474	$replacement = esc_html( $search );
475	}
476
477	return $replacement;
478	}
479
480	/**
481	* Retrieve the separator for use as replacement string.
482	*
483	* @return string Retrieves the title separator.
484	*/
485	private function retrieve_sep() {
486	return YoastSEO()->helpers->options->get_title_separator();
487	}
488
489	/**
490	* Retrieve the site's tag line / description for use as replacement string.
491	*
492	* The `$replacement` variable is static because it doesn't change depending
493	* on the context. See https://github.com/Yoast/wordpress-seo/pull/1172#issuecomment-46019482.
494	*
495	* @return string\|null
496	*/
497	private function retrieve_sitedesc() {
498	static $replacement;
499
500	if ( ! isset( $replacement ) ) {
501	$description = wp_strip_all_tags( get_bloginfo( 'description' ) );
502	if ( $description !== '' ) {
503	$replacement = $description;
504	}
505	}
506
507	return $replacement;
508	}
509
510	/**
511	* Retrieve the site's name for use as replacement string.
512	*
513	* The `$replacement` variable is static because it doesn't change depending
514	* on the context. See https://github.com/Yoast/wordpress-seo/pull/1172#issuecomment-46019482.
515	*
516	* @return string\|null
517	*/
518	private function retrieve_sitename() {
519	static $replacement;
520
521	if ( ! isset( $replacement ) ) {
522	$sitename = YoastSEO()->helpers->site->get_site_name();
523	if ( $sitename !== '' ) {
524	$replacement = $sitename;
525	}
526	}
527
528	return $replacement;
529	}
530
531	/**
532	* Retrieve the current tag/tags for use as replacement string.
533	*
534	* @return string\|null
535	*/
536	private function retrieve_tag() {
537	$replacement = null;
538
539	if ( ! empty( $this->args->ID ) ) {
540	$tags = $this->get_terms( $this->args->ID, 'post_tag' );
541	if ( $tags !== '' ) {
542	$replacement = $tags;
543	}
544	}
545
546	return $replacement;
547	}
548
549	/**
550	* Retrieve the tag description for use as replacement string.
551	*
552	* @return string\|null
553	*/
554	private function retrieve_tag_description() {
555	return $this->retrieve_term_description();
556	}
557
558	/**
559	* Retrieve the term description for use as replacement string.
560	*
561	* @return string\|null
562	*/
563	private function retrieve_term_description() {
564	$replacement = null;
565
566	if ( ! empty( $this->args->term_id ) && ! empty( $this->args->taxonomy ) ) {
567	$term_desc = get_term_field( 'description', $this->args->term_id, $this->args->taxonomy );
568	if ( $term_desc !== '' ) {
569	$replacement = wp_strip_all_tags( $term_desc );
570	}
571	}
572
573	return $replacement;
574	}
575
576	/**
577	* Retrieve the term name for use as replacement string.
578	*
579	* @return string\|null
580	*/
581	private function retrieve_term_title() {
582	$replacement = null;
583
584	if ( ! empty( $this->args->taxonomy ) && ! empty( $this->args->name ) ) {
585	$replacement = $this->args->name;
586	}
587
588	return $replacement;
589	}
590
591	/**
592	* Retrieve the title of the post/page/cpt for use as replacement string.
593	*
594	* @return string\|null
595	*/
596	private function retrieve_title() {
597	$replacement = null;
598
599	if ( is_string( $this->args->post_title ) && $this->args->post_title !== '' ) {
600	$replacement = $this->args->post_title;
601	}
602
603	return $replacement;
604	}
605
606	/**
607	* Retrieve primary category for use as replacement string.
608	*
609	* @return bool\|int\|null
610	*/
611	private function retrieve_primary_category() {
612	$primary_category = null;
613
614	if ( ! empty( $this->args->ID ) ) {
615	$wpseo_primary_category = new WPSEO_Primary_Term( 'category', $this->args->ID );
616
617	$term_id = $wpseo_primary_category->get_primary_term();
618	$term = get_term( $term_id );
619
620	if ( ! is_wp_error( $term ) && ! empty( $term ) ) {
621	$primary_category = $term->name;
622	}
623	}
624
625	return $primary_category;
626	}
627
628	/**
629	* Retrieve the string generated by get_the_archive_title().
630	*
631	* @return string\|null
632	*/
633	private function retrieve_archive_title() {
634	return get_the_archive_title();
635	}
636
637	/* ********************* ADVANCED VARIABLES ************************ */
638
639	/**
640	* Determine the page numbering of the current post/page/cpt.
641	*
642	* @param string $request Either 'nr'\|'max' - whether to return the page number or the max number of pages.
643	*
644	* @return int\|null
645	*/
646	private function determine_pagenumbering( $request = 'nr' ) {
647	global $wp_query, $post;
648	$max_num_pages = null;
649	$page_number = null;
650
651	$max_num_pages = 1;
652
653	if ( ! is_singular() ) {
654	$page_number = get_query_var( 'paged' );
655	if ( $page_number === 0 \|\| $page_number === '' ) {
656	$page_number = 1;
657	}
658
659	if ( ! empty( $wp_query->max_num_pages ) ) {
660	$max_num_pages = $wp_query->max_num_pages;
661	}
662	}
663	else {
664	$page_number = get_query_var( 'page' );
665	if ( $page_number === 0 \|\| $page_number === '' ) {
666	$page_number = 1;
667	}
668
669	if ( isset( $post->post_content ) ) {
670	$max_num_pages = ( substr_count( $post->post_content, '<!--nextpage-->' ) + 1 );
671	}
672	}
673
674	$return = null;
675
676	switch ( $request ) {
677	case 'nr':
678	$return = $page_number;
679	break;
680	case 'max':
681	$return = $max_num_pages;
682	break;
683	}
684
685	return $return;
686	}
687
688	/**
689	* Determine the post type names for the current post/page/cpt.
690	*
691	* @param string $request Either 'single'\|'plural' - whether to return the single or plural form.
692	*
693	* @return string\|null
694	*/
695	private function determine_pt_names( $request = 'single' ) {
696	global $wp_query;
697	$pt_single = null;
698	$pt_plural = null;
699	$post_type = '';
700
701	if ( isset( $wp_query->query_vars['post_type'] ) && ( ( is_string( $wp_query->query_vars['post_type'] ) && $wp_query->query_vars['post_type'] !== '' ) \|\| ( is_array( $wp_query->query_vars['post_type'] ) && $wp_query->query_vars['post_type'] !== [] ) ) ) {
702	$post_type = $wp_query->query_vars['post_type'];
703	}
704	elseif ( isset( $this->args->post_type ) && ( is_string( $this->args->post_type ) && $this->args->post_type !== '' ) ) {
705	$post_type = $this->args->post_type;
706	}
707	else {
708	// Make it work in preview mode.
709	$post = $wp_query->get_queried_object();
710	if ( $post instanceof WP_Post ) {
711	$post_type = $post->post_type;
712	}
713	}
714
715	if ( is_array( $post_type ) ) {
716	$post_type = reset( $post_type );
717	}
718
719	if ( $post_type !== '' ) {
720	$pt = get_post_type_object( $post_type );
721	$pt_single = $pt->name;
722	$pt_plural = $pt->name;
723	if ( isset( $pt->labels->singular_name ) ) {
724	$pt_single = $pt->labels->singular_name;
725	}
726	if ( isset( $pt->labels->name ) ) {
727	$pt_plural = $pt->labels->name;
728	}
729	}
730
731	$return = null;
732
733	switch ( $request ) {
734	case 'single':
735	$return = $pt_single;
736	break;
737	case 'plural':
738	$return = $pt_plural;
739	break;
740	}
741
742	return $return;
743	}
744
745	/**
746	* Retrieve the attachment caption for use as replacement string.
747	*
748	* @return string\|null
749	*/
750	private function retrieve_caption() {
751	return $this->retrieve_excerpt_only();
752	}
753
754	/**
755	* Retrieve a post/page/cpt's custom field value for use as replacement string.
756	*
757	* @param string $var_to_replace The complete variable to replace which includes the name of
758	* the custom field which value is to be retrieved.
759	*
760	* @return string\|null
761	*/
762	private function retrieve_cf_custom_field_name( $var_to_replace ) {
763	$replacement = null;
764
765	if ( is_string( $var_to_replace ) && $var_to_replace !== '' ) {
766	$field = substr( $var_to_replace, 3 );
767	if ( ! empty( $this->args->ID ) ) {
768	// Post meta can be arrays and in this case we need to exclude them.
769	$name = get_post_meta( $this->args->ID, $field, true );
770	if ( $name !== '' && ! is_array( $name ) ) {
771	$replacement = $name;
772	}
773	}
774	elseif ( ! empty( $this->args->term_id ) ) {
775	$name = get_term_meta( $this->args->term_id, $field, true );
776	if ( $name !== '' ) {
777	$replacement = $name;
778	}
779	}
780	}
781
782	return $replacement;
783	}
784
785	/**
786	* Retrieve a post/page/cpt's custom taxonomies for use as replacement string.
787	*
788	* @param string $var_to_replace The complete variable to replace which includes the name of
789	* the custom taxonomy which value(s) is to be retrieved.
790	* @param bool $single Whether to retrieve only the first or all values for the taxonomy.
791	*
792	* @return string\|null
793	*/
794	private function retrieve_ct_custom_tax_name( $var_to_replace, $single = false ) {
795	$replacement = null;
796
797	if ( ( is_string( $var_to_replace ) && $var_to_replace !== '' ) && ! empty( $this->args->ID ) ) {
798	$tax = substr( $var_to_replace, 3 );
799	$name = $this->get_terms( $this->args->ID, $tax, $single );
800	if ( $name !== '' ) {
801	$replacement = $name;
802	}
803	}
804
805	return $replacement;
806	}
807
808	/**
809	* Retrieve a post/page/cpt's custom taxonomies description for use as replacement string.
810	*
811	* @param string $var_to_replace The complete variable to replace which includes the name of
812	* the custom taxonomy which description is to be retrieved.
813	*
814	* @return string\|null
815	*/
816	private function retrieve_ct_desc_custom_tax_name( $var_to_replace ) {
817	$replacement = null;
818
819	if ( is_string( $var_to_replace ) && $var_to_replace !== '' ) {
820	$tax = substr( $var_to_replace, 8 );
821	if ( ! empty( $this->args->ID ) ) {
822	$terms = get_the_terms( $this->args->ID, $tax );
823	if ( is_array( $terms ) && $terms !== [] ) {
824	$term = current( $terms );
825	$term_desc = get_term_field( 'description', $term->term_id, $tax );
826	if ( $term_desc !== '' ) {
827	$replacement = wp_strip_all_tags( $term_desc );
828	}
829	}
830	}
831	}
832
833	return $replacement;
834	}
835
836	/**
837	* Retrieve the current date for use as replacement string.
838	*
839	* The `$replacement` variable is static because it doesn't change depending
840	* on the context. See https://github.com/Yoast/wordpress-seo/pull/1172#issuecomment-46019482.
841	*
842	* @return string The formatted current date.
843	*/
844	private function retrieve_currentdate() {
845	static $replacement;
846
847	if ( ! isset( $replacement ) ) {
848	$replacement = date_i18n( get_option( 'date_format' ) );
849	}
850
851	return $replacement;
852	}
853
854	/**
855	* Retrieve the current day for use as replacement string.
856	*
857	* The `$replacement` variable is static because it doesn't change depending
858	* on the context. See https://github.com/Yoast/wordpress-seo/pull/1172#issuecomment-46019482.
859	*
860	* @return string The current day.
861	*/
862	private function retrieve_currentday() {
863	static $replacement;
864
865	if ( ! isset( $replacement ) ) {
866	$replacement = date_i18n( 'j' );
867	}
868
869	return $replacement;
870	}
871
872	/**
873	* Retrieve the current month for use as replacement string.
874	*
875	* The `$replacement` variable is static because it doesn't change depending
876	* on the context. See https://github.com/Yoast/wordpress-seo/pull/1172#issuecomment-46019482.
877	*
878	* @return string The current month.
879	*/
880	private function retrieve_currentmonth() {
881	static $replacement;
882
883	if ( ! isset( $replacement ) ) {
884	$replacement = date_i18n( 'F' );
885	}
886
887	return $replacement;
888	}
889
890	/**
891	* Retrieve the current time for use as replacement string.
892	*
893	* The `$replacement` variable is static because it doesn't change depending
894	* on the context. See https://github.com/Yoast/wordpress-seo/pull/1172#issuecomment-46019482.
895	*
896	* @return string The formatted current time.
897	*/
898	private function retrieve_currenttime() {
899	static $replacement;
900
901	if ( ! isset( $replacement ) ) {
902	$replacement = date_i18n( get_option( 'time_format' ) );
903	}
904
905	return $replacement;
906	}
907
908	/**
909	* Retrieve the current year for use as replacement string.
910	*
911	* The `$replacement` variable is static because it doesn't change depending
912	* on the context. See https://github.com/Yoast/wordpress-seo/pull/1172#issuecomment-46019482.
913	*
914	* @return string The current year.
915	*/
916	private function retrieve_currentyear() {
917	static $replacement;
918
919	if ( ! isset( $replacement ) ) {
920	$replacement = date_i18n( 'Y' );
921	}
922
923	return $replacement;
924	}
925
926	/**
927	* Retrieve the post/page/cpt's focus keyword for use as replacement string.
928	*
929	* @return string\|null
930	*/
931	private function retrieve_focuskw() {
932	// Retrieve focuskw from a Post.
933	if ( ! empty( $this->args->ID ) ) {
934	$focus_kw = WPSEO_Meta::get_value( 'focuskw', $this->args->ID );
935	if ( $focus_kw !== '' ) {
936	return $focus_kw;
937	}
938
939	return null;
940	}
941
942	// Retrieve focuskw from a Term.
943	if ( ! empty( $this->args->term_id ) ) {
944	$focus_kw = WPSEO_Taxonomy_Meta::get_term_meta( $this->args->term_id, $this->args->taxonomy, 'focuskw' );
945	if ( $focus_kw !== '' ) {
946	return $focus_kw;
947	}
948	}
949
950	return null;
951	}
952
953	/**
954	* Retrieve the post/page/cpt ID for use as replacement string.
955	*
956	* @return string\|null
957	*/
958	private function retrieve_id() {
959	$replacement = null;
960
961	if ( ! empty( $this->args->ID ) ) {
962	// The post/page/cpt ID is an integer, let's cast to string.
963	$replacement = (string) $this->args->ID;
964	}
965
966	return $replacement;
967	}
968
969	/**
970	* Retrieve the post/page/cpt modified time for use as replacement string.
971	*
972	* @return string\|null
973	*/
974	private function retrieve_modified() {
975	$replacement = null;
976
977	if ( ! empty( $this->args->post_modified ) ) {
978	$replacement = YoastSEO()->helpers->date->format_translated( $this->args->post_modified, get_option( 'date_format' ) );
979	}
980
981	return $replacement;
982	}
983
984	/**
985	* Retrieve the post/page/cpt author's "nice name" for use as replacement string.
986	*
987	* @return string\|null
988	*/
989	private function retrieve_name() {
990	$replacement = null;
991
992	$user_id = (int) $this->retrieve_userid();
993	$name = get_the_author_meta( 'display_name', $user_id );
994	if ( $name !== '' ) {
995	$replacement = $name;
996	}
997
998	return $replacement;
999	}
1000
1001	/**
1002	* Retrieve the post/page/cpt author's users description for use as a replacement string.
1003	*
1004	* @return string\|null
1005	*/
1006	private function retrieve_user_description() {
1007	$replacement = null;
1008
1009	$user_id = (int) $this->retrieve_userid();
1010	$description = get_the_author_meta( 'description', $user_id );
1011	if ( $description !== '' ) {
1012	$replacement = $description;
1013	}
1014
1015	return $replacement;
1016	}
1017
1018	/**
1019	* Retrieve the current page number with context (i.e. 'page 2 of 4') for use as replacement string.
1020	*
1021	* @return string
1022	*/
1023	private function retrieve_page() {
1024	$replacement = null;
1025
1026	$max = $this->determine_pagenumbering( 'max' );
1027	$nr = $this->determine_pagenumbering( 'nr' );
1028	$sep = $this->retrieve_sep();
1029
1030	if ( $max > 1 && $nr > 1 ) {
1031	/* translators: 1: current page number, 2: total number of pages. */
1032	$replacement = sprintf( $sep . ' ' . __( 'Page %1$d of %2$d', 'wordpress-seo' ), $nr, $max );
1033	}
1034
1035	return $replacement;
1036	}
1037
1038	/**
1039	* Retrieve the current page number for use as replacement string.
1040	*
1041	* @return string\|null
1042	*/
1043	private function retrieve_pagenumber() {
1044	$replacement = null;
1045
1046	$nr = $this->determine_pagenumbering( 'nr' );
1047	if ( isset( $nr ) && $nr > 0 ) {
1048	$replacement = (string) $nr;
1049	}
1050
1051	return $replacement;
1052	}
1053
1054	/**
1055	* Retrieve the current page total for use as replacement string.
1056	*
1057	* @return string\|null
1058	*/
1059	private function retrieve_pagetotal() {
1060	$replacement = null;
1061
1062	$max = $this->determine_pagenumbering( 'max' );
1063	if ( isset( $max ) && $max > 0 ) {
1064	$replacement = (string) $max;
1065	}
1066
1067	return $replacement;
1068	}
1069
1070	/**
1071	* Retrieve the post type plural label for use as replacement string.
1072	*
1073	* @return string\|null
1074	*/
1075	private function retrieve_pt_plural() {
1076	$replacement = null;
1077
1078	$name = $this->determine_pt_names( 'plural' );
1079	if ( isset( $name ) && $name !== '' ) {
1080	$replacement = $name;
1081	}
1082
1083	return $replacement;
1084	}
1085
1086	/**
1087	* Retrieve the post type single label for use as replacement string.
1088	*
1089	* @return string\|null
1090	*/
1091	private function retrieve_pt_single() {
1092	$replacement = null;
1093
1094	$name = $this->determine_pt_names( 'single' );
1095	if ( isset( $name ) && $name !== '' ) {
1096	$replacement = $name;
1097	}
1098
1099	return $replacement;
1100	}
1101
1102	/**
1103	* Retrieve the slug which caused the 404 for use as replacement string.
1104	*
1105	* @return string\|null
1106	*/
1107	private function retrieve_term404() {
1108	$replacement = null;
1109
1110	if ( $this->args->term404 !== '' ) {
1111	$replacement = sanitize_text_field( str_replace( '-', ' ', $this->args->term404 ) );
1112	}
1113	else {
1114	$error_request = get_query_var( 'pagename' );
1115	if ( $error_request !== '' ) {
1116	$replacement = sanitize_text_field( str_replace( '-', ' ', $error_request ) );
1117	}
1118	else {
1119	$error_request = get_query_var( 'name' );
1120	if ( $error_request !== '' ) {
1121	$replacement = sanitize_text_field( str_replace( '-', ' ', $error_request ) );
1122	}
1123	}
1124	}
1125
1126	return $replacement;
1127	}
1128
1129	/**
1130	* Retrieve the post/page/cpt author's user id for use as replacement string.
1131	*
1132	* @return string
1133	*/
1134	private function retrieve_userid() {
1135	// The user ID is an integer, let's cast to string.
1136	$replacement = ! empty( $this->args->post_author ) ? (string) $this->args->post_author : (string) get_query_var( 'author' );
1137
1138	return $replacement;
1139	}
1140
1141	/**
1142	* Retrieve the post/page/cpt's published year for use as replacement string.
1143	*
1144	* @return string\|null
1145	*/
1146	private function retrieve_post_year() {
1147	if ( empty( $this->args->ID ) ) {
1148	return null;
1149	}
1150
1151	return \get_the_date( 'Y', $this->args->ID );
1152	}
1153
1154	/**
1155	* Retrieve the post/page/cpt's published month for use as replacement string.
1156	*
1157	* @return string\|null
1158	*/
1159	private function retrieve_post_month() {
1160	if ( empty( $this->args->ID ) ) {
1161	return null;
1162	}
1163
1164	return \get_the_date( 'F', $this->args->ID );
1165	}
1166
1167	/**
1168	* Retrieve the post/page/cpt's published day for use as replacement string.
1169	*
1170	* @return string\|null
1171	*/
1172	private function retrieve_post_day() {
1173	if ( empty( $this->args->ID ) ) {
1174	return null;
1175	}
1176
1177	return \get_the_date( 'd', $this->args->ID );
1178	}
1179
1180	/**
1181	* Retrieve the post/page/cpt author's first name for use as replacement string.
1182	*
1183	* @return string\|null
1184	*/
1185	private function retrieve_author_first_name() {
1186	$replacement = null;
1187
1188	$user_id = (int) $this->retrieve_userid();
1189	$name = get_the_author_meta( 'first_name', $user_id );
1190	if ( $name !== '' ) {
1191	$replacement = $name;
1192	}
1193
1194	return $replacement;
1195	}
1196
1197	/**
1198	* Retrieve the post/page/cpt author's last name for use as replacement string.
1199	*
1200	* @return string\|null
1201	*/
1202	private function retrieve_author_last_name() {
1203	$replacement = null;
1204
1205	$user_id = (int) $this->retrieve_userid();
1206	$name = get_the_author_meta( 'last_name', $user_id );
1207	if ( $name !== '' ) {
1208	$replacement = $name;
1209	}
1210
1211	return $replacement;
1212	}
1213
1214	/**
1215	* Retrieve the post/page/cpt permalink for use as replacement string.
1216	*
1217	* @return string\|null
1218	*/
1219	private function retrieve_permalink() {
1220	if ( empty( $this->args->ID ) ) {
1221	return null;
1222	}
1223
1224	return \get_permalink( $this->args->ID );
1225	}
1226
1227	/**
1228	* Retrieve the post/page/cpt content for use as replacement string.
1229	*
1230	* @return string\|null
1231	*/
1232	private function retrieve_post_content() {
1233	$replacement = null;
1234
1235	// The check `post_password_required` is because content must be hidden for a post with a password.
1236	if ( ! empty( $this->args->ID ) && $this->args->post_content !== '' && ! post_password_required( $this->args->ID ) ) {
1237	$content = strip_shortcodes( $this->args->post_content );
1238	$replacement = wp_strip_all_tags( $content );
1239	}
1240
1241	return $replacement;
1242	}
1243
1244	/**
1245	* Retrieve the current or first category title. To be used for import data from AIOSEO.
1246	* The code derives from AIOSEO's way of dealing with that var, so we can ensure 100% seamless transition.
1247	*
1248	* @return string\|null
1249	*/
1250	private function retrieve_category_title() {
1251	if ( empty( $this->args ) \|\| empty( $this->args->ID ) ) {
1252	return null;
1253	}
1254	$post_id = $this->args->ID;
1255
1256	$post = get_post( $post_id );
1257	$taxonomies = get_object_taxonomies( $post, 'objects' );
1258
1259	foreach ( $taxonomies as $taxonomy_slug => $taxonomy ) {
1260	if ( ! $taxonomy->hierarchical ) {
1261	continue;
1262	}
1263	$post_terms = get_the_terms( $post_id, $taxonomy_slug );
1264	if ( is_array( $post_terms ) && count( $post_terms ) > 0 ) {
1265	// AiOSEO takes the name of whatever the first hierarchical taxonomy is.
1266	$term = $post_terms[0];
1267	if ( $term ) {
1268	return $term->name;
1269	}
1270	}
1271	}
1272
1273	return null;
1274	}
1275
1276	/* ********************* HELP TEXT RELATED ************************ */
1277
1278	/**
1279	* Set the help text for a user/plugin/theme defined extra variable.
1280	*
1281	* @param string $type Type of variable: 'basic' or 'advanced'.
1282	* @param WPSEO_Replacement_Variable $replacement_variable The replacement variable to register.
1283	*/
1284	private static function register_help_text( $type, WPSEO_Replacement_Variable $replacement_variable ) {
1285	$identifier = $replacement_variable->get_variable();
1286
1287	if ( ( is_string( $type ) && in_array( $type, [ 'basic', 'advanced' ], true ) )
1288	&& ( $identifier !== '' && ! isset( self::$help_texts[ $type ][ $identifier ] ) )
1289	) {
1290	self::$help_texts[ $type ][ $identifier ] = $replacement_variable;
1291	}
1292	}
1293
1294	/**
1295	* Generates a list of replacement variables based on the help texts.
1296	*
1297	* @return array List of replace vars.
1298	*/
1299	public function get_replacement_variables_with_labels() {
1300	self::setup_statics_once();
1301
1302	$custom_variables = [];
1303	foreach ( array_merge( WPSEO_Custom_Fields::get_custom_fields(), WPSEO_Custom_Taxonomies::get_custom_taxonomies() ) as $custom_variable ) {
1304	$custom_variables[ $custom_variable ] = new WPSEO_Replacement_Variable( $custom_variable, $this->get_label( $custom_variable ), '' );
1305	}
1306
1307	$replacement_variables = array_filter(
1308	array_merge( self::$help_texts['basic'], self::$help_texts['advanced'] ),
1309	[ $this, 'is_not_prefixed' ],
1310	ARRAY_FILTER_USE_KEY
1311	);
1312
1313	$hidden = $this->get_hidden_replace_vars();
1314
1315	return array_values(
1316	array_map(
1317	static function ( WPSEO_Replacement_Variable $replacement_variable ) use ( $hidden ) {
1318	$name = $replacement_variable->get_variable();
1319
1320	return [
1321	'name' => $name,
1322	'value' => '',
1323	'label' => $replacement_variable->get_label(),
1324	'hidden' => in_array( $name, $hidden, true ),
1325	];
1326	},
1327	array_merge( $replacement_variables, $custom_variables )
1328	)
1329	);
1330	}
1331
1332	/**
1333	* Generates a list of replacement variables based on the help texts.
1334	*
1335	* @return array List of replace vars.
1336	*/
1337	public function get_replacement_variables_list() {
1338	self::setup_statics_once();
1339
1340	$replacement_variables = array_merge(
1341	$this->get_replacement_variables(),
1342	WPSEO_Custom_Fields::get_custom_fields(),
1343	WPSEO_Custom_Taxonomies::get_custom_taxonomies()
1344	);
1345
1346	return array_map( [ $this, 'format_replacement_variable' ], $replacement_variables );
1347	}
1348
1349	/**
1350	* Creates a merged associative array of both the basic and advanced help texts.
1351	*
1352	* @return array Array with the replacement variables.
1353	*/
1354	private function get_replacement_variables() {
1355	$help_texts = array_merge( self::$help_texts['basic'], self::$help_texts['advanced'] );
1356
1357	return array_filter( array_keys( $help_texts ), [ $this, 'is_not_prefixed' ] );
1358	}
1359
1360	/**
1361	* Checks whether the replacement variable contains a `ct_` or `cf_` prefix, because they follow different logic.
1362	*
1363	* @param string $replacement_variable The replacement variable.
1364	*
1365	* @return bool True when the replacement variable is not prefixed.
1366	*/
1367	private function is_not_prefixed( $replacement_variable ) {
1368	$prefixes = [ 'cf_', 'ct_' ];
1369	$prefix = $this->get_prefix( $replacement_variable );
1370
1371	return ! in_array( $prefix, $prefixes, true );
1372	}
1373
1374	/**
1375	* Strip the prefix from a replacement variable name.
1376	*
1377	* @param string $replacement_variable The replacement variable.
1378	*
1379	* @return string The replacement variable name without the prefix.
1380	*/
1381	private function strip_prefix( $replacement_variable ) {
1382	return substr( $replacement_variable, 3 );
1383	}
1384
1385	/**
1386	* Gets the prefix from a replacement variable name.
1387	*
1388	* @param string $replacement_variable The replacement variable.
1389	*
1390	* @return string The prefix of the replacement variable.
1391	*/
1392	private function get_prefix( $replacement_variable ) {
1393	return substr( $replacement_variable, 0, 3 );
1394	}
1395
1396	/**
1397	* Strips 'desc_' if present, and appends ' description' at the end.
1398	*
1399	* @param string $label The replacement variable.
1400	*
1401	* @return string The altered replacement variable name.
1402	*/
1403	private function handle_description( $label ) {
1404	if ( strpos( $label, 'desc_' ) === 0 ) {
1405	return substr( $label, 5 ) . ' description';
1406	}
1407
1408	return $label;
1409	}
1410
1411	/**
1412	* Creates a label for prefixed replacement variables that matches the format in the editors.
1413	*
1414	* @param string $replacement_variable The replacement variable.
1415	*
1416	* @return string The replacement variable label.
1417	*/
1418	private function get_label( $replacement_variable ) {
1419	$prefix = $this->get_prefix( $replacement_variable );
1420	if ( $prefix === 'cf_' ) {
1421	return $this->strip_prefix( $replacement_variable ) . ' (custom field)';
1422	}
1423
1424	if ( $prefix === 'ct_' ) {
1425	$label = $this->strip_prefix( $replacement_variable );
1426	$label = $this->handle_description( $label );
1427	return ucfirst( $label . ' (custom taxonomy)' );
1428	}
1429
1430	if ( $prefix === 'pt_' ) {
1431	if ( $replacement_variable === 'pt_single' ) {
1432	return 'Post type (singular)';
1433	}
1434
1435	return 'Post type (plural)';
1436	}
1437
1438	return '';
1439	}
1440
1441	/**
1442	* Formats the replacement variables.
1443	*
1444	* @param string $replacement_variable The replacement variable to format.
1445	*
1446	* @return array The formatted replacement variable.
1447	*/
1448	private function format_replacement_variable( $replacement_variable ) {
1449	return [
1450	'name' => $replacement_variable,
1451	'value' => '',
1452	'label' => $this->get_label( $replacement_variable ),
1453	];
1454	}
1455
1456	/**
1457	* Set/translate the help texts for the WPSEO standard basic variables.
1458	*/
1459	private static function set_basic_help_texts() {
1460	/* translators: %s: wp_title() function. */
1461	$separator_description = __( 'The separator defined in your theme\'s %s tag.', 'wordpress-seo' );
1462	$separator_description = sprintf(
1463	$separator_description,
1464	// '<code>wp_title()</code>'
1465	'wp_title()'
1466	);
1467
1468	$replacement_variables = [
1469	new WPSEO_Replacement_Variable( 'date', __( 'Date', 'wordpress-seo' ), __( 'Replaced with the date of the post/page', 'wordpress-seo' ) ),
1470	new WPSEO_Replacement_Variable( 'title', __( 'Title', 'wordpress-seo' ), __( 'Replaced with the title of the post/page', 'wordpress-seo' ) ),
1471	new WPSEO_Replacement_Variable( 'parent_title', __( 'Parent title', 'wordpress-seo' ), __( 'Replaced with the title of the parent page of the current page', 'wordpress-seo' ) ),
1472	new WPSEO_Replacement_Variable( 'archive_title', __( 'Archive title', 'wordpress-seo' ), __( 'Replaced with the normal title for an archive generated by WordPress', 'wordpress-seo' ) ),
1473	new WPSEO_Replacement_Variable( 'sitename', __( 'Site title', 'wordpress-seo' ), __( 'The site\'s name', 'wordpress-seo' ) ),
1474	new WPSEO_Replacement_Variable( 'sitedesc', __( 'Tagline', 'wordpress-seo' ), __( 'The site\'s tagline', 'wordpress-seo' ) ),
1475	new WPSEO_Replacement_Variable( 'excerpt', __( 'Excerpt', 'wordpress-seo' ), __( 'Replaced with the post/page excerpt (or auto-generated if it does not exist)', 'wordpress-seo' ) ),
1476	new WPSEO_Replacement_Variable( 'excerpt_only', __( 'Excerpt only', 'wordpress-seo' ), __( 'Replaced with the post/page excerpt (without auto-generation)', 'wordpress-seo' ) ),
1477	new WPSEO_Replacement_Variable( 'tag', __( 'Tag', 'wordpress-seo' ), __( 'Replaced with the current tag/tags', 'wordpress-seo' ) ),
1478	new WPSEO_Replacement_Variable( 'category', __( 'Category', 'wordpress-seo' ), __( 'Replaced with the post categories (comma separated)', 'wordpress-seo' ) ),
1479	new WPSEO_Replacement_Variable( 'primary_category', __( 'Primary category', 'wordpress-seo' ), __( 'Replaced with the primary category of the post/page', 'wordpress-seo' ) ),
1480	new WPSEO_Replacement_Variable( 'category_description', __( 'Category description', 'wordpress-seo' ), __( 'Replaced with the category description', 'wordpress-seo' ) ),
1481	new WPSEO_Replacement_Variable( 'tag_description', __( 'Tag description', 'wordpress-seo' ), __( 'Replaced with the tag description', 'wordpress-seo' ) ),
1482	new WPSEO_Replacement_Variable( 'term_description', __( 'Term description', 'wordpress-seo' ), __( 'Replaced with the term description', 'wordpress-seo' ) ),
1483	new WPSEO_Replacement_Variable( 'term_title', __( 'Term title', 'wordpress-seo' ), __( 'Replaced with the term name', 'wordpress-seo' ) ),
1484	new WPSEO_Replacement_Variable( 'searchphrase', __( 'Search phrase', 'wordpress-seo' ), __( 'Replaced with the current search phrase', 'wordpress-seo' ) ),
1485	new WPSEO_Replacement_Variable( 'term_hierarchy', __( 'Term hierarchy', 'wordpress-seo' ), __( 'Replaced with the term ancestors hierarchy', 'wordpress-seo' ) ),
1486	new WPSEO_Replacement_Variable( 'sep', __( 'Separator', 'wordpress-seo' ), $separator_description ),
1487	new WPSEO_Replacement_Variable( 'currentdate', __( 'Current date', 'wordpress-seo' ), __( 'Replaced with the current date', 'wordpress-seo' ) ),
1488	new WPSEO_Replacement_Variable( 'currentyear', __( 'Current year', 'wordpress-seo' ), __( 'Replaced with the current year', 'wordpress-seo' ) ),
1489	new WPSEO_Replacement_Variable( 'currentmonth', __( 'Current month', 'wordpress-seo' ), __( 'Replaced with the current month', 'wordpress-seo' ) ),
1490	new WPSEO_Replacement_Variable( 'currentday', __( 'Current day', 'wordpress-seo' ), __( 'Replaced with the current day', 'wordpress-seo' ) ),
1491	new WPSEO_Replacement_Variable( 'post_year', __( 'Post year', 'wordpress-seo' ), __( 'Replaced with the year the post was published', 'wordpress-seo' ) ),
1492	new WPSEO_Replacement_Variable( 'post_month', __( 'Post month', 'wordpress-seo' ), __( 'Replaced with the month the post was published', 'wordpress-seo' ) ),
1493	new WPSEO_Replacement_Variable( 'post_day', __( 'Post day', 'wordpress-seo' ), __( 'Replaced with the day the post was published', 'wordpress-seo' ) ),
1494	new WPSEO_Replacement_Variable( 'author_first_name', __( 'Author first name', 'wordpress-seo' ), __( 'Replaced with the first name of the author', 'wordpress-seo' ) ),
1495	new WPSEO_Replacement_Variable( 'author_last_name', __( 'Author last name', 'wordpress-seo' ), __( 'Replaced with the last name of the author', 'wordpress-seo' ) ),
1496	new WPSEO_Replacement_Variable( 'permalink', __( 'Permalink', 'wordpress-seo' ), __( 'Replaced with the permalink', 'wordpress-seo' ) ),
1497	new WPSEO_Replacement_Variable( 'post_content', __( 'Post Content', 'wordpress-seo' ), __( 'Replaced with the post content', 'wordpress-seo' ) ),
1498	new WPSEO_Replacement_Variable( 'category_title', __( 'Category Title', 'wordpress-seo' ), __( 'Current or first category title', 'wordpress-seo' ) ),
1499	];
1500
1501	foreach ( $replacement_variables as $replacement_variable ) {
1502	self::register_help_text( 'basic', $replacement_variable );
1503	}
1504	}
1505
1506	/**
1507	* Set/translate the help texts for the WPSEO standard advanced variables.
1508	*/
1509	private static function set_advanced_help_texts() {
1510	$replacement_variables = [
1511	new WPSEO_Replacement_Variable( 'pt_single', __( 'Post type (singular)', 'wordpress-seo' ), __( 'Replaced with the content type single label', 'wordpress-seo' ) ),
1512	new WPSEO_Replacement_Variable( 'pt_plural', __( 'Post type (plural)', 'wordpress-seo' ), __( 'Replaced with the content type plural label', 'wordpress-seo' ) ),
1513	new WPSEO_Replacement_Variable( 'modified', __( 'Modified', 'wordpress-seo' ), __( 'Replaced with the post/page modified time', 'wordpress-seo' ) ),
1514	new WPSEO_Replacement_Variable( 'id', __( 'ID', 'wordpress-seo' ), __( 'Replaced with the post/page ID', 'wordpress-seo' ) ),
1515	new WPSEO_Replacement_Variable( 'name', __( 'Name', 'wordpress-seo' ), __( 'Replaced with the post/page author\'s \'nicename\'', 'wordpress-seo' ) ),
1516	new WPSEO_Replacement_Variable( 'user_description', __( 'User description', 'wordpress-seo' ), __( 'Replaced with the post/page author\'s \'Biographical Info\'', 'wordpress-seo' ) ),
1517	new WPSEO_Replacement_Variable( 'page', __( 'Page', 'wordpress-seo' ), __( 'Replaced with the current page number with context (i.e. page 2 of 4)', 'wordpress-seo' ) ),
1518	new WPSEO_Replacement_Variable( 'pagetotal', __( 'Pagetotal', 'wordpress-seo' ), __( 'Replaced with the current page total', 'wordpress-seo' ) ),
1519	new WPSEO_Replacement_Variable( 'pagenumber', __( 'Pagenumber', 'wordpress-seo' ), __( 'Replaced with the current page number', 'wordpress-seo' ) ),
1520	new WPSEO_Replacement_Variable( 'caption', __( 'Caption', 'wordpress-seo' ), __( 'Attachment caption', 'wordpress-seo' ) ),
1521	new WPSEO_Replacement_Variable( 'focuskw', __( 'Focus keyword', 'wordpress-seo' ), __( 'Replaced with the posts focus keyphrase', 'wordpress-seo' ) ),
1522	new WPSEO_Replacement_Variable( 'term404', __( 'Term404', 'wordpress-seo' ), __( 'Replaced with the slug which caused the 404', 'wordpress-seo' ) ),
1523	new WPSEO_Replacement_Variable( 'cf_<custom-field-name>', '<custom-field-name> ' . __( '(custom field)', 'wordpress-seo' ), __( 'Replaced with a posts custom field value', 'wordpress-seo' ) ),
1524	new WPSEO_Replacement_Variable( 'ct_<custom-tax-name>', '<custom-tax-name> ' . __( '(custom taxonomy)', 'wordpress-seo' ), __( 'Replaced with a posts custom taxonomies, comma separated.', 'wordpress-seo' ) ),
1525	new WPSEO_Replacement_Variable( 'ct_desc_<custom-tax-name>', '<custom-tax-name> ' . __( 'description (custom taxonomy)', 'wordpress-seo' ), __( 'Replaced with a custom taxonomies description', 'wordpress-seo' ) ),
1526	];
1527
1528	foreach ( $replacement_variables as $replacement_variable ) {
1529	self::register_help_text( 'advanced', $replacement_variable );
1530	}
1531	}
1532
1533	/* ********************* GENERAL HELPER METHODS ************************ */
1534
1535	/**
1536	* Remove the '%%' delimiters from a variable string.
1537	*
1538	* @param string $text Variable string to be cleaned.
1539	*
1540	* @return string
1541	*/
1542	private static function remove_var_delimiter( $text ) {
1543	return trim( $text, '%' );
1544	}
1545
1546	/**
1547	* Add the '%%' delimiters to a variable string.
1548	*
1549	* @param string $text Variable string to be delimited.
1550	*
1551	* @return string
1552	*/
1553	private static function add_var_delimiter( $text ) {
1554	return '%%' . $text . '%%';
1555	}
1556
1557	/**
1558	* Retrieve a post's terms, comma delimited.
1559	*
1560	* @param int $id ID of the post to get the terms for.
1561	* @param string $taxonomy The taxonomy to get the terms for this post from.
1562	* @param bool $return_single If true, return the first term.
1563	*
1564	* @return string Either a single term or a comma delimited string of terms.
1565	*/
1566	public function get_terms( $id, $taxonomy, $return_single = false ) {
1567	$output = '';
1568
1569	// If we're on a specific tag, category or taxonomy page, use that.
1570	if ( ! empty( $this->args->term_id ) ) {
1571	$output = $this->args->name;
1572	}
1573	elseif ( ! empty( $id ) && ! empty( $taxonomy ) ) {
1574	$terms = get_the_terms( $id, $taxonomy );
1575	if ( is_array( $terms ) && $terms !== [] ) {
1576	foreach ( $terms as $term ) {
1577	if ( $return_single ) {
1578	$output = $term->name;
1579	break;
1580	}
1581	else {
1582	$output .= $term->name . ', ';
1583	}
1584	}
1585	$output = rtrim( trim( $output ), ',' );
1586	}
1587	}
1588	unset( $terms, $term );
1589
1590	/**
1591	* Allows filtering of the terms list used to replace %%category%%, %%tag%%
1592	* and %%ct_<custom-tax-name>%% variables.
1593	*
1594	* @api string $output Comma-delimited string containing the terms.
1595	* @api string $taxonomy The taxonomy of the terms.
1596	*/
1597	return apply_filters( 'wpseo_terms', $output, $taxonomy );
1598	}
1599
1600	/**
1601	* Gets a taxonomy term hierarchy including the term to get the parents for.
1602	*
1603	* @return string
1604	*/
1605	private function get_term_hierarchy() {
1606	if ( ! is_taxonomy_hierarchical( $this->args->taxonomy ) ) {
1607	return '';
1608	}
1609
1610	$separator = ' ' . $this->retrieve_sep() . ' ';
1611
1612	$args = [
1613	'format' => 'name',
1614	'separator' => $separator,
1615	'link' => false,
1616	'inclusive' => true,
1617	];
1618
1619	return rtrim(
1620	get_term_parents_list( $this->args->term_id, $this->args->taxonomy, $args ),
1621	$separator
1622	);
1623	}
1624
1625	/**
1626	* Retrieves the term ancestors hierarchy.
1627	*
1628	* @return string\|null The term ancestors hierarchy.
1629	*/
1630	private function retrieve_term_hierarchy() {
1631	$replacement = null;
1632
1633	if ( ! empty( $this->args->term_id ) && ! empty( $this->args->taxonomy ) ) {
1634	$hierarchy = $this->get_term_hierarchy();
1635
1636	if ( $hierarchy !== '' ) {
1637	$replacement = esc_html( $hierarchy );
1638	}
1639	}
1640
1641	return $replacement;
1642	}
1643	}
1644