mxchat-basic / includes / class-mxchat-cache-purge.php

class-mxchat-cache-purge.php in MxChat – AI Chatbot & Content Generation for WordPress 3.2.25, at includes/class-mxchat-cache-purge.php

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1	<?php
2	if (!defined('ABSPATH')) {
3	exit;
4	}
5
6	/**
7	* MxChat_Cache_Purge — purges known full-page caches when MxChat settings save.
8	*
9	* Widget settings are printed inline into page HTML (wp_localize_script in
10	* class-mxchat-integrator.php), so a full-page cache keeps serving the old
11	* snapshot after an admin changes a setting — toggles look broken until the
12	* cache is cleared by hand. This module clears the page caches we can reach
13	* from PHP the moment mxchat_options is written, using each cache plugin's
14	* own public purge API (guarded by existence checks, so absent plugins are
15	* a no-op). Companion to the 3.2.6 page-cache compatibility filters in
16	* mxchat-basic.php, which keep the chat AJAX endpoints out of those same
17	* caches; this handles the cached page HTML itself.
18	*
19	* Host-level caches and CDNs (Cloudflare APO etc.) cannot be purged from
20	* PHP — for those, the widget re-fetches its behavior settings when opened
21	* (see MxChat_Integrator::get_dynamic_widget_settings()).
22	*
23	* Debounce: the admin screen autosaves per field, so a settings session can
24	* write mxchat_options many times in a minute. We purge at most once per
25	* DEBOUNCE_SECONDS; writes that land inside the window schedule one deferred
26	* purge via wp-cron so the final state always gets flushed.
27	*
28	* @since 3.2.9 (plan-32db95)
29	*/
30	class MxChat_Cache_Purge {
31
32	const DEBOUNCE_TRANSIENT = 'mxchat_cache_purge_debounce';
33	const DEBOUNCE_SECONDS = 30;
34	const DEFERRED_EVENT = 'mxchat_deferred_cache_purge';
35
36	/**
37	* Owner switch (plan b76ed6, Support Ticket 468: a 1,400-page FlyingPress
38	* site lost its whole preload on every settings save). Standalone option,
39	* 'on' / 'off'; absent means ON so existing sites keep today's behaviour.
40	* Rendered on Settings → Optimization → Page Cache Compatibility and saved
41	* by the mxchat_cache_purge_enabled case in class-ajax-handler.php.
42	*
43	* The switch is read when a watched option is actually written (and when
44	* a deferred purge fires), not at plugin load: the hooks below cost
45	* nothing until a save happens, and a site that never touches the switch
46	* never pays a get_option() for it on a visitor request.
47	*/
48	const OPTION_NAME = 'mxchat_cache_purge_enabled';
49
50	private static $instance = null;
51
52	/**
53	* Whether this request already queued a shutdown purge (one per request).
54	*
55	* @var bool
56	*/
57	private $purge_queued = false;
58
59	public static function init() {
60	if (self::$instance === null) {
61	self::$instance = new self();
62	}
63	return self::$instance;
64	}
65
66	/**
67	* Whether MxChat clears page caches when its settings are saved.
68	* Default ON; only an explicit 'off' switches it off.
69	*
70	* @return bool
71	*/
72	public static function is_enabled() {
73	return get_option(self::OPTION_NAME, 'on') !== 'off';
74	}
75
76	private function __construct() {
77	foreach ($this->watched_options() as $option_name) {
78	add_action('update_option_' . $option_name, array($this, 'queue_purge'), 10, 0);
79	add_action('add_option_' . $option_name, array($this, 'queue_purge'), 10, 0);
80	}
81	add_action(self::DEFERRED_EVENT, array($this, 'purge_page_caches'));
82	}
83
84	/**
85	* Option names whose writes trigger a page-cache purge.
86	*
87	* Defaults cover every option whose values reach the cached page's inline
88	* widget payload: mxchat_options (settings/behavior gates),
89	* mxchat_theme_options (active AI theme CSS + bot theme assignments —
90	* written only by the MxChat Theme add-on's admin AJAX actions), and
91	* mxchat_prompts_options (Pinecone toggle — written only by the prompts
92	* autosave). All write sites are admin-action-driven; the debounce
93	* absorbs back-to-back writes like apply-and-save.
94	*
95	* @return string[]
96	*/
97	private function watched_options() {
98	$defaults = array('mxchat_options', 'mxchat_theme_options', 'mxchat_prompts_options');
99	$options = apply_filters('mxchat_cache_purge_watched_options', $defaults);
100	return is_array($options) ? array_filter(array_map('strval', $options)) : $defaults;
101	}
102
103	/**
104	* Coalesce all option writes in this request into one shutdown purge.
105	*/
106	public function queue_purge() {
107	if ($this->purge_queued \|\| !self::is_enabled()) {
108	return;
109	}
110	$this->purge_queued = true;
111	add_action('shutdown', array($this, 'run_queued_purge'), 5);
112	}
113
114	/**
115	* Shutdown handler: purge unless one ran inside the debounce window; in
116	* that case schedule a single deferred purge so the last write still wins.
117	*/
118	public function run_queued_purge() {
119	if (get_transient(self::DEBOUNCE_TRANSIENT)) {
120	if (!wp_next_scheduled(self::DEFERRED_EVENT)) {
121	wp_schedule_single_event(time() + self::DEBOUNCE_SECONDS, self::DEFERRED_EVENT);
122	}
123	return;
124	}
125	set_transient(self::DEBOUNCE_TRANSIENT, 1, self::DEBOUNCE_SECONDS);
126	$this->purge_page_caches();
127	}
128
129	/**
130	* Purge every supported page cache via its own public API. Each call is
131	* guarded so installs without that plugin skip it silently.
132	*/
133	public function purge_page_caches() {
134	// The owner may have switched the purge off after a deferred purge was
135	// scheduled; off means off.
136	if (!self::is_enabled()) {
137	return;
138	}
139
140	// WP Rocket — public helper, clears the whole domain's page cache.
141	if (function_exists('rocket_clean_domain')) {
142	rocket_clean_domain();
143	}
144
145	// LiteSpeed Cache — documented third-party purge API.
146	if (defined('LSCWP_V') \|\| class_exists('LiteSpeed\Core')) {
147	do_action('litespeed_purge_all');
148	}
149
150	// W3 Total Cache — page-cache flush helper.
151	if (function_exists('w3tc_pgcache_flush')) {
152	w3tc_pgcache_flush();
153	}
154
155	// WP Super Cache — global cache clear.
156	if (function_exists('wp_cache_clear_cache')) {
157	wp_cache_clear_cache();
158	}
159
160	// FlyingPress — documented programmatic purge (purge_pages clears the
161	// HTML page cache without rebuilding optimized assets):
162	// https://docs.flyingpress.com/en/articles/11406092-programmatically-purge-and-preload-cache
163	if (class_exists('\FlyingPress\Purge') && method_exists('\FlyingPress\Purge', 'purge_pages')) {
164	\FlyingPress\Purge::purge_pages();
165	}
166
167	// Extension point for CDNs / host caches / custom setups.
168	do_action('mxchat_purge_page_caches');
169	}
170	}
171