thinkrank / includes / seo / class-cache-purger.php

class-cache-purger.php in ThinkRank AI SEO – AI SEO Plugin for WordPress: Schema, XML Sitemaps, Meta Tags, Search Console & Local SEO 2.12.0, at includes/seo/class-cache-purger.php

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1	<?php
2
3	/**
4	* Cache purging for content ThinkRank rewrites underneath a cache.
5	*
6	* ThinkRank writes values that other software has already rendered into HTML
7	* and stored. Alt text is the clearest case: `update-image-alt-text` writes
8	* `_wp_attachment_image_alt` and returns success, while the page a visitor
9	* loads still carries the old words because Elementor kept the rendered widget
10	* in post meta and a page cache kept the whole document. The write is correct
11	* and invisible, which is the worst possible combination for an agent that
12	* reports back to a user (#763).
13	*
14	* Two layers are dealt with here:
15	*
16	* - Builder output caches. Elementor stores rendered elements per document
17	* in `_elementor_element_cache` and reuses them for up to 24 hours. Element
18	* caching is on unless the site turns it off: `Document::print_elements()`
19	* treats any value of `elementor_element_cache_ttl` except the literal
20	* `disable` as enabled, and the option does not exist on a default install.
21	* Elementor's own public API for this is `files_manager->clear_cache()`,
22	* which also deletes every generated CSS file on the site. Deleting the one
23	* meta key on the affected documents is the narrow equivalent, and it is
24	* what Elementor's protected `Document::delete_cache()` does.
25	* - Page and CDN caches. The same set `LLMs_Txt_Manager` has purged since
26	* 2.1.0, moved here so more than one feature can reach it.
27	*
28	* What cannot be purged is reported rather than ignored. A site behind Varnish,
29	* a CDN, or a caching plugin with no per-URL API will keep serving the old
30	* markup no matter what this class does, and the caller needs to be told that
31	* so it can tell the user to clear it by hand instead of insisting the change
32	* has gone live.
33	*
34	* @package ThinkRank
35	* @subpackage SEO
36	* @since 2.12.0
37	*/
38
39	declare(strict_types=1);
40
41	namespace ThinkRank\SEO;
42
43	// Prevent direct access
44	if (!defined('ABSPATH')) {
45	exit;
46	}
47
48	/**
49	* Drops cached copies of pages ThinkRank has just changed.
50	*
51	* @since 2.12.0
52	*/
53	class Cache_Purger {
54
55	/**
56	* Elementor's per-document rendered-element cache.
57	*
58	* Mirrors `Elementor\Core\Base\Document::CACHE_META_KEY`. The literal is
59	* used rather than the constant because Elementor may not be loaded, and
60	* because reaching into another plugin's class for a meta key is a harder
61	* dependency than repeating the string with this note attached.
62	*
63	* @since 2.12.0
64	* @var string
65	*/
66	public const ELEMENTOR_CACHE_META_KEY = '_elementor_element_cache';
67
68	/**
69	* Post IDs already purged during this request.
70	*
71	* A library-wide alt fill touches hundreds of attachments that between them
72	* appear on a handful of pages, so without this the same document is
73	* cleared once per image. Per-request only: nothing here needs to survive
74	* into the next one, and a stale memory of "already purged" across requests
75	* would be a correctness bug rather than an optimisation.
76	*
77	* @since 2.12.0
78	* @var array<int, bool>
79	*/
80	private static array $purged = [];
81
82	/**
83	* Caching plugins ThinkRank knows about, and whether it can purge them.
84	*
85	* Detection is a presence check on the plugin's own constant or class, not
86	* on its purge function: a plugin that loads after this one would report as
87	* absent, and the plugins that matter most for the warning are the ones
88	* that expose no purge function at all.
89	*
90	* @since 2.12.0
91	* @return array<string, array{detect: callable, purgeable: bool}>
92	*/
93	private static function known_caches(): array {
94	return [
95	'WP Rocket' => [
96	'detect' => static fn(): bool => defined('WP_ROCKET_VERSION'),
97	'purgeable' => true,
98	],
99	'W3 Total Cache' => [
100	'detect' => static fn(): bool => defined('W3TC'),
101	'purgeable' => true,
102	],
103	'WP Super Cache' => [
104	'detect' => static fn(): bool => defined('WPCACHEHOME'),
105	'purgeable' => true,
106	],
107	'LiteSpeed Cache' => [
108	'detect' => static fn(): bool => defined('LSCWP_V'),
109	'purgeable' => true,
110	],
111	'Nginx Helper' => [
112	'detect' => static fn(): bool => class_exists('Nginx_Helper'),
113	'purgeable' => true,
114	],
115	// Everything below is detected but not purgeable from here. Each
116	// one either exposes no per-URL API or needs credentials ThinkRank
117	// does not hold, so the honest answer is a warning to the caller.
118	'WP Fastest Cache' => [
119	'detect' => static fn(): bool => defined('WPFC_MAIN_PATH') \|\| class_exists('WpFastestCache'),
120	'purgeable' => false,
121	],
122	'SiteGround Optimizer' => [
123	'detect' => static fn(): bool => class_exists('SiteGround_Optimizer\\Supercacher\\Supercacher'),
124	'purgeable' => false,
125	],
126	'Cache Enabler' => [
127	'detect' => static fn(): bool => class_exists('Cache_Enabler'),
128	'purgeable' => false,
129	],
130	'Breeze' => [
131	'detect' => static fn(): bool => defined('BREEZE_VERSION'),
132	'purgeable' => false,
133	],
134	'Hummingbird' => [
135	'detect' => static fn(): bool => defined('WPHB_VERSION'),
136	'purgeable' => false,
137	],
138	'Cloudflare' => [
139	'detect' => static fn(): bool => class_exists('CF\\WordPress\\Hooks'),
140	'purgeable' => false,
141	],
142	];
143	}
144
145	/**
146	* Ask every cache layer to drop its copy of the given URLs.
147	*
148	* Every integration is guarded, so a site running none of them simply gets
149	* the action hook, which other integrations can listen on.
150	*
151	* @since 2.12.0
152	* @param string[] $urls Absolute URLs to purge.
153	* @return void
154	*/
155	public static function purge_urls(array $urls): void {
156	$urls = array_values(array_unique(array_filter(array_map('strval', $urls))));
157
158	if ([] === $urls) {
159	return;
160	}
161
162	/**
163	* Fires when ThinkRank changes what a URL serves.
164	*
165	* Cache layers ThinkRank does not know about can listen here and drop
166	* their copy.
167	*
168	* @since 2.12.0
169	*
170	* @param string[] $urls Absolute URLs whose content has changed.
171	*/
172	do_action('thinkrank_purge_urls', $urls);
173
174	// Each integration is guarded by its own API rather than by the
175	// detector above, so a plugin whose constant this file guesses wrong
176	// still gets purged. The detector decides only what to warn about.
177	// These are third-party hook names ThinkRank fires, not ours to prefix.
178	foreach ($urls as $url) {
179	do_action('litespeed_purge_url', $url); // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
180
181	if (function_exists('w3tc_flush_url')) {
182	w3tc_flush_url($url);
183	}
184	if (function_exists('wpsc_delete_url_cache')) {
185	wpsc_delete_url_cache($url);
186	}
187	}
188
189	// Nginx Helper only exposes a purge-everything hook, and WP Rocket
190	// takes the whole list at once, so both run once per call.
191	do_action('rt_nginx_helper_purge_all'); // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
192
193	if (function_exists('rocket_clean_files')) {
194	rocket_clean_files($urls);
195	}
196	}
197
198	/**
199	* Drop cached renderings of specific posts, then their public URLs.
200	*
201	* @since 2.12.0
202	* @param int[] $post_ids Posts whose rendered output is now out of date.
203	* @return int[] The post IDs actually purged in this request.
204	*/
205	public static function purge_posts(array $post_ids): array {
206	$purged = [];
207	$urls = [];
208
209	foreach ($post_ids as $post_id) {
210	$post_id = (int) $post_id;
211
212	if ($post_id <= 0 \|\| isset(self::$purged[$post_id])) {
213	continue;
214	}
215
216	self::$purged[$post_id] = true;
217	$purged[] = $post_id;
218
219	// Elementor rebuilds the document on the next front-end request
220	// once the meta is gone. Deleting it is safe on a post Elementor
221	// never touched: the key simply is not there.
222	delete_post_meta($post_id, self::ELEMENTOR_CACHE_META_KEY);
223
224	clean_post_cache($post_id);
225
226	$permalink = get_permalink($post_id);
227	if (is_string($permalink) && '' !== $permalink) {
228	$urls[] = $permalink;
229	}
230	}
231
232	if ([] !== $urls) {
233	self::purge_urls($urls);
234	}
235
236	return $purged;
237	}
238
239	/**
240	* Caching layers that are installed but cannot be purged from here.
241	*
242	* @since 2.12.0
243	* @return string[] Plugin names, in the order they are declared.
244	*/
245	public static function unpurgeable_caches(): array {
246	$names = [];
247
248	foreach (self::known_caches() as $name => $cache) {
249	if (!$cache['purgeable'] && ($cache['detect'])()) {
250	$names[] = $name;
251	}
252	}
253
254	return $names;
255	}
256
257	/**
258	* Sentences describing what a caller still has to clear by hand.
259	*
260	* Returned to the MCP abilities so an agent can pass the caveat on instead
261	* of reporting an unqualified success the visitor cannot see yet.
262	*
263	* @since 2.12.0
264	* @return string[] Empty when everything detected was purged.
265	*/
266	public static function warnings(): array {
267	$unpurgeable = self::unpurgeable_caches();
268
269	if ([] === $unpurgeable) {
270	return [];
271	}
272
273	return [
274	sprintf(
275	/* translators: %s: comma-separated list of caching plugin names. */
276	__('%s is active and offers no way to clear a single page from here. Clear its cache to see the change on the front end.', 'thinkrank'),
277	implode(', ', $unpurgeable)
278	),
279	];
280	}
281
282	/**
283	* Forget which posts were purged this request.
284	*
285	* Only the test suite needs this: a single web request never purges the
286	* same post twice on purpose.
287	*
288	* @since 2.12.0
289	* @return void
290	*/
291	public static function reset(): void {
292	self::$purged = [];
293	}
294	}
295