xspeed / includes / class-minify-filters.php

class-minify-filters.php in xSpeed Cache: AI-Powered Performance Hub with MCP, Caching & CDN 1.0.3, at includes/class-minify-filters.php

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1	<?php
2	/**
3	* Minify_Filters — frontend HTML rewriters for the "smarter minifier"
4	* sub-features (Phase 4.1a): defer JS, delay JS, async CSS, remove
5	* query strings.
6	*
7	* Each method is a WordPress filter callback. None of them touch the
8	* file system — they're pure tag rewrites or src-string rewrites
9	* applied to enqueued asset URLs / tags.
10	*
11	* The heavier combine-CSS / combine-JS engine lands in Phase 4.1b
12	* with its own class; keeping the filter-only logic isolated here
13	* makes that future split clean.
14	*
15	* @package XSpeed
16	*/
17
18	declare(strict_types=1);
19
20	namespace XSpeed;
21
22	defined( 'ABSPATH' ) \|\| exit;
23
24	final class Minify_Filters {
25
26	/**
27	* Settings cache (one read per request).
28	*
29	* @var array\|null
30	*/
31	private static $opts = null;
32
33	/**
34	* Has the delay-JS bootstrap snippet been printed? Guards against
35	* duplicate emission in pages that hit wp_footer multiple times.
36	*/
37	private static $delay_bootstrap_printed = false;
38
39	/**
40	* Filter: `script_loader_tag` — add defer="defer" to non-excluded
41	* scripts. WordPress passes the full <script> tag string, the
42	* handle, and the src. We bail when:
43	* - the user excluded this handle / src substring,
44	* - the tag already has defer or async (don't double-set),
45	* - the tag has no src (inline scripts can't be deferred — would
46	* execute synchronously regardless).
47	*
48	* @param string $tag
49	* @param string $handle
50	* @param string $src
51	*/
52	public static function defer_script_tag( $tag, $handle, $src ): string {
53	if ( ! is_string( $tag ) \|\| '' === $tag ) {
54	return (string) $tag;
55	}
56	// Self-guard: even though Minifier::__construct() bails on admin/
57	// AJAX/REST/cron at registration, a late context switch (e.g. a
58	// custom wp_print_scripts() call inside an admin page render) can
59	// leave the filter attached. Skipping here keeps the React admin
60	// bundle's <script> tag intact so the dashboard mounts.
61	if ( self::skip_in_non_frontend_context() ) {
62	return $tag;
63	}
64	if ( '' === (string) $src ) {
65	return $tag;
66	}
67	if ( self::is_excluded_script( (string) $handle, (string) $src ) ) {
68	return $tag;
69	}
70	if ( false !== stripos( $tag, ' defer' ) \|\| false !== stripos( $tag, ' async' ) ) {
71	return $tag;
72	}
73	return (string) preg_replace( '#<script\b#i', '<script defer="defer"', $tag, 1 );
74	}
75
76	/**
77	* Filter: `script_loader_tag` — rewrite src= to data-xs-src= so the
78	* browser ignores it until the bootstrap (printed once on
79	* wp_footer) swaps it back on first user interaction. Same
80	* exclusion rules as defer. Inline scripts (no src) are also
81	* deferred until the first interaction.
82	*
83	* @param string $tag
84	* @param string $handle
85	* @param string $src
86	*/
87	public static function delay_script_tag( $tag, $handle, $src ): string {
88	if ( ! is_string( $tag ) \|\| '' === $tag ) {
89	return (string) $tag;
90	}
91	if ( self::skip_in_non_frontend_context() ) {
92	return $tag;
93	}
94	if ( self::is_excluded_script( (string) $handle, (string) $src ) ) {
95	return $tag;
96	}
97	// src= variant: swap src → data-xs-src and add data-xs-delay marker.
98	if ( '' !== (string) $src ) {
99	return (string) preg_replace(
100	'#\bsrc\s=\s(["\'][^"\']*["\'])#i',
101	'data-xs-src=$1 data-xs-delay="1"',
102	$tag,
103	1
104	);
105	}
106	// Inline script: change type to text/plain so the browser
107	// doesn't execute, mark for bootstrap rewriter.
108	return (string) preg_replace(
109	'#<script\b([^>]*)>#i',
110	'<script$1 type="text/xspeed-delayed" data-xs-delay="1">',
111	$tag,
112	1
113	);
114	}
115
116	/**
117	* Inline bootstrap that flips delayed scripts on the first user
118	* interaction. Printed once on wp_footer priority 1000.
119	*/
120	public static function print_delay_bootstrap(): void {
121	if ( self::skip_in_non_frontend_context() ) {
122	return;
123	}
124	if ( self::$delay_bootstrap_printed ) {
125	return;
126	}
127	self::$delay_bootstrap_printed = true;
128	// Tiny vanilla bootstrap; keep it self-contained so the page
129	// has no JS dependencies before the first interaction.
130	?>
131	<script id="xspeed-delay-bootstrap">
132	(function(){
133	var events=['mousemove','keydown','touchstart','scroll','wheel'];
134	var fired=false;
135	function load(){
136	if(fired)return;fired=true;
137	events.forEach(function(e){window.removeEventListener(e,load,{passive:true,capture:true});});
138	var delayed=document.querySelectorAll('script[data-xs-delay]');
139	delayed.forEach(function(s){
140	var n=document.createElement('script');
141	Array.prototype.slice.call(s.attributes).forEach(function(a){
142	if(a.name==='data-xs-src'){n.setAttribute('src',a.value);return;}
143	if(a.name==='data-xs-delay'\|\|a.name==='type')return;
144	n.setAttribute(a.name,a.value);
145	});
146	if(!s.hasAttribute('data-xs-src')){n.text=s.text;}
147	s.parentNode.replaceChild(n,s);
148	});
149	}
150	events.forEach(function(e){window.addEventListener(e,load,{passive:true,capture:true});});
151	setTimeout(load,8000);
152	})();
153	</script>
154	<?php
155	}
156
157	/**
158	* Filter: `style_loader_tag` — wrap stylesheets in the
159	* print → onload="all" pattern so they download non-blocking.
160	* Pairs with critical CSS workflows. Adds a <noscript> fallback so
161	* users with JS disabled still get styles applied (via media="all").
162	*
163	* @param string $tag
164	* @param string $handle
165	*/
166	public static function async_style_tag( $tag, $handle ): string {
167	if ( ! is_string( $tag ) \|\| '' === $tag ) {
168	return (string) $tag;
169	}
170	if ( self::skip_in_non_frontend_context() ) {
171	return $tag;
172	}
173	// Only operate on <link rel=stylesheet> with a media attribute
174	// we can swap. Skip anything custom (preload, etc.) — we don't
175	// want to fight with explicit author intent.
176	if ( false === stripos( $tag, 'rel=\'stylesheet\'' ) && false === stripos( $tag, 'rel="stylesheet"' ) ) {
177	return $tag;
178	}
179	// Avoid double-wrapping.
180	if ( false !== stripos( $tag, 'data-xs-async' ) ) {
181	return $tag;
182	}
183	$async = (string) preg_replace_callback(
184	'#\bmedia\s=\s(["\'])([^"\']*)\1#i',
185	static function ( $m ) {
186	$orig = $m[2];
187	return 'media="print" onload="this.media=\'' . esc_attr( $orig ) . '\'" data-xs-async="' . esc_attr( $orig ) . '"';
188	},
189	$tag,
190	1
191	);
192	// If no media= was present (rare), inject one.
193	if ( $async === $tag ) {
194	$async = (string) preg_replace(
195	'#<link\b#i',
196	'<link media="print" onload="this.media=\'all\'" data-xs-async="all"',
197	$tag,
198	1
199	);
200	}
201	// Fallback for noscript users — re-emit the original tag inside <noscript>.
202	return $async . '<noscript>' . $tag . '</noscript>';
203	}
204
205	/**
206	* Filter: `style_loader_src` + `script_loader_src` — strip the
207	* ?ver=X.Y query string that WP appends for cache busting. Some
208	* CDNs / reverse proxies cache better when the URL has no query.
209	*
210	* Skip URLs whose query carries non-ver params — those might be
211	* intentional (e.g. a CDN providing per-image transforms).
212	*
213	* @param string $src
214	*/
215	public static function strip_version_query( $src ): string {
216	if ( ! is_string( $src ) \|\| '' === $src ) {
217	return (string) $src;
218	}
219	if ( self::skip_in_non_frontend_context() ) {
220	return $src;
221	}
222	$parts = wp_parse_url( $src );
223	if ( ! is_array( $parts ) \|\| empty( $parts['query'] ) ) {
224	return $src;
225	}
226	parse_str( $parts['query'], $query );
227	if ( ! is_array( $query ) ) {
228	return $src;
229	}
230	// Only strip 'ver' — keep anything else the asset URL needs.
231	unset( $query['ver'] );
232	$new_query = http_build_query( $query );
233	$new_url = ( $parts['scheme'] ?? 'http' ) . '://' . ( $parts['host'] ?? '' );
234	if ( isset( $parts['port'] ) ) {
235	$new_url .= ':' . $parts['port'];
236	}
237	$new_url .= $parts['path'] ?? '';
238	if ( '' !== $new_query ) {
239	$new_url .= '?' . $new_query;
240	}
241	if ( ! empty( $parts['fragment'] ) ) {
242	$new_url .= '#' . $parts['fragment'];
243	}
244	return $new_url;
245	}
246
247	/**
248	* Defensive context guard for filter callbacks. Mirrors the registration-
249	* time bail in Minifier::__construct() so a late context flip (admin page
250	* render kicked off mid-request, REST_REQUEST set after plugins_loaded,
251	* etc.) doesn't let frontend tag rewrites leak into wp-admin / AJAX /
252	* REST / cron responses.
253	*
254	* Specifically prevents the React admin bundle's <script> tag from being
255	* deferred or src-swapped to data-xs-src — which would stop the dashboard
256	* from booting and make toggles appear unchecked until first interaction.
257	*/
258	private static function skip_in_non_frontend_context(): bool {
259	if ( is_admin() ) {
260	return true;
261	}
262	if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
263	return true;
264	}
265	if ( defined( 'DOING_CRON' ) && DOING_CRON ) {
266	return true;
267	}
268	if ( defined( 'REST_REQUEST' ) && REST_REQUEST ) {
269	return true;
270	}
271	return false;
272	}
273
274	/**
275	* Built-in exclusion list — always skipped regardless of user settings.
276	* Covers our own admin bundle and the WP script-modules it depends on,
277	* so that even if the registration-time admin guard is somehow bypassed,
278	* the dashboard's React app can still boot.
279	*/
280	private const ALWAYS_EXCLUDED_HANDLES = array(
281	'xspeed-admin',
282	'wp-hooks',
283	'wp-i18n',
284	'wp-url',
285	'wp-api-fetch',
286	);
287
288	private static function is_excluded_script( string $handle, string $src ): bool {
289	if ( in_array( $handle, self::ALWAYS_EXCLUDED_HANDLES, true ) ) {
290	return true;
291	}
292	$opts = self::opts();
293	$excluded = is_array( $opts['defer_js_excluded'] ?? null ) ? $opts['defer_js_excluded'] : array();
294	if ( empty( $excluded ) ) {
295	return false;
296	}
297	foreach ( $excluded as $needle ) {
298	$needle = (string) $needle;
299	if ( '' === $needle ) {
300	continue;
301	}
302	if ( $handle === $needle \|\| false !== stripos( $src, $needle ) ) {
303	return true;
304	}
305	}
306	return false;
307	}
308
309	private static function opts(): array {
310	if ( null === self::$opts ) {
311	self::$opts = Settings_Manager::get( 'minify' );
312	}
313	return self::$opts;
314	}
315
316	/**
317	* Test-only — clear cached opts + bootstrap-printed flag.
318	*/
319	public static function reset_state(): void {
320	self::$opts = null;
321	self::$delay_bootstrap_printed = false;
322	}
323	}
324