powered-cache / includes / classes / FileOptimizer.php

FileOptimizer.php in Powered Cache – Caching and Optimization for WordPress – Easily Improve PageSpeed & Web Vitals Score 3.7, at includes/classes/FileOptimizer.php

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1	<?php
2	/**
3	* File optimizer (minify, contact) related functionalities
4	*
5	* @package PoweredCache
6	*/
7
8	namespace PoweredCache;
9
10	use PoweredCache\Dependencies\voku\helper\HtmlMin;
11	use const PoweredCache\Constants\POST_META_DISABLE_CSS_OPTIMIZATION;
12	use const PoweredCache\Constants\POST_META_DISABLE_JS_DEFER;
13	use const PoweredCache\Constants\POST_META_DISABLE_JS_DELAY;
14	use const PoweredCache\Constants\POST_META_DISABLE_JS_OPTIMIZATION;
15	use PoweredCache\Optimizer\CSS;
16	use PoweredCache\Optimizer\Helper;
17	use PoweredCache\Optimizer\JS;
18	use function PoweredCache\Utils\get_cache_dir;
19	use function PoweredCache\Utils\remove_dir;
20
21
22	/**
23	* Class FileOptimizer
24	*/
25	class FileOptimizer {
26	/**
27	* Plugin settings
28	*
29	* @var array
30	*/
31	public $settings = [];
32
33	/**
34	* Do optimizations for wp-admin?
35	*
36	* @var bool
37	*/
38	public $optimize_dashboard;
39
40
41	/**
42	* Return an instance of the current class
43	*
44	* @return FileOptimizer
45	* @since 1.0
46	*/
47	public static function factory() {
48	static $instance = false;
49
50	if ( ! $instance ) {
51	$instance = new self();
52	$instance->setup();
53	}
54
55	return $instance;
56	}
57
58	/**
59	* Setup routine
60	*/
61	public function setup() {
62	$this->settings = \PoweredCache\Utils\get_settings();
63
64	// Check request method
65	if ( ! isset( $_SERVER['REQUEST_METHOD'] ) \|\| ! in_array( $_SERVER['REQUEST_METHOD'], [ 'GET', 'HEAD' ], true ) ) {
66	return true;
67	}
68
69	add_action( 'plugins_loaded', [ $this, 'setup_file_optimizer' ] );
70
71	}
72
73	/**
74	* Setup file optimizer module
75	*/
76	public function setup_file_optimizer() {
77	/**
78	* Filters whether apply or not apply file optimizations on wp-admin.
79	*
80	* @hook powered_cache_fo_dashboard
81	*
82	* @param {boolean} true to enable optimizations for dashboard.
83	*
84	* @return {boolean} New value.
85	* @since 2.0
86	*/
87	$this->optimize_dashboard = apply_filters( 'powered_cache_fo_dashboard', false );
88
89	add_action( 'powered_cache_purge_all_cache', [ $this, 'maybe_purge_fo_cache' ] );
90
91	/**
92	* Don't optimize wp-admin by default
93	* This might worth to add as option?
94	*/
95
96	if ( is_admin() && ! $this->optimize_dashboard ) {
97	return;
98	}
99
100	/**
101	* Don't optimize in customizer preview
102	*/
103	if ( ! empty( $_GET['customize_changeset_uuid'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended
104	\PoweredCache\Utils\log( 'Do not run file optimizer in customizer preview' );
105
106	return;
107	}
108
109	/**
110	* Filters FileOptimizer integration
111	*
112	* @hook powered_cache_fo_disable
113	*
114	* @param {boolean} False by default.
115	*
116	* @return {boolean} New value.
117	* @since 2.2
118	*/
119	$disable_file_optimizer = apply_filters( 'powered_cache_fo_disable', false );
120
121	if ( $disable_file_optimizer ) {
122	return;
123	}
124
125	add_action( 'init', [ $this, 'setup_css_combine' ] );
126	add_action( 'init', [ $this, 'setup_js_combine' ] );
127	add_filter( 'script_loader_tag', [ $this, 'js_minify' ], 10, 3 );
128	add_filter( 'style_loader_tag', [ $this, 'css_minify' ], 10, 4 );
129	add_filter( 'powered_cache_fo_script_loader_tag', [ $this, 'change_js_execute_method' ] );
130	add_filter( 'script_loader_tag', [ $this, 'change_js_execute_method' ], 99 );
131	add_action( 'after_setup_theme', [ $this, 'maybe_start_buffer' ], 999 );
132	add_action( 'template_redirect', [ $this, 'maybe_suppress_optimizations' ] );
133
134	if ( ! $this->settings['combine_js'] ) {
135	add_filter( 'powered_cache_fo_js_do_concat', '__return_false' );
136	}
137
138	if ( ! $this->settings['combine_css'] ) {
139	add_filter( 'powered_cache_fo_css_do_concat', '__return_false' );
140	}
141
142	if ( $this->settings['combine_google_fonts'] ) {
143	add_action( 'wp_enqueue_scripts', [ $this, 'combine_google_fonts' ], 99 );
144	}
145	}
146
147	/**
148	* Process output buffer
149	*
150	* @return void
151	*/
152	public function maybe_start_buffer() {
153	if ( ! isset( $_SERVER['REQUEST_URI'] ) ) {
154	return;
155	}
156	$request_uri = sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) );
157
158	if ( strpos( $request_uri, 'robots.txt' ) !== false \|\| strpos( $request_uri, '.htaccess' ) !== false ) {
159	return;
160	}
161
162	if ( ! isset( $_SERVER['REQUEST_METHOD'] ) \|\| 'GET' !== $_SERVER['REQUEST_METHOD'] ) {
163	return;
164	}
165
166	$file_extension = preg_replace( '#^(.?)\?.$#', '$1', $request_uri );
167	$file_extension = trim( preg_replace( '#^.\.(.)$#', '$1', $file_extension ) );
168
169	if ( ! preg_match( '#index\.php$#i', $request_uri ) && in_array( $file_extension, array( 'php', 'xml', 'xsl' ), true ) ) {
170	return;
171	}
172
173	if ( defined( 'REST_REQUEST' ) && REST_REQUEST ) {
174	return;
175	}
176
177	ob_start( [ $this, 'process_buffer' ] );
178	}
179
180	/**
181	* Process output buffer
182	*
183	* @param string $html Output buffer
184	*
185	* @return string\|string[]\|null
186	*/
187	public function process_buffer( $html ) {
188	$html = $this->maybe_defer_inline_scripts( $html );
189	$html = $this->maybe_delay_scripts( $html );
190	$html = $this->maybe_replace_google_fonts_with_bunny_fonts( $html );
191	$html = $this->maybe_minify_html( $html );
192
193	return $html;
194	}
195
196	/**
197	* Replace Google Fonts with Bunny drop-in replacement's
198	*
199	* @param string $html Output buffer
200	*
201	* @return array\|mixed\|string\|string[]
202	* @since 3.0
203	*/
204	public function maybe_replace_google_fonts_with_bunny_fonts( $html ) {
205	if ( ! $this->settings['use_bunny_fonts'] ) {
206	return $html;
207	}
208
209	$html = str_replace(
210	[
211	'https://fonts.googleapis.com',
212	'http://fonts.googleapis.com',
213	'//fonts.googleapis.com',
214	],
215	'https://fonts.bunny.net',
216	$html
217	);
218
219	return $html;
220	}
221
222	/**
223	* Maybe suppress optimizations based on the post meta options
224	*
225	* @since 2.1
226	*/
227	public function maybe_suppress_optimizations() {
228	if ( is_singular() ) {
229	$disable_css_optimization = (bool) get_post_meta( get_the_ID(), POST_META_DISABLE_CSS_OPTIMIZATION, true );
230	$disable_js_optimization = (bool) get_post_meta( get_the_ID(), POST_META_DISABLE_JS_OPTIMIZATION, true );
231	$disable_js_defer = (bool) get_post_meta( get_the_ID(), POST_META_DISABLE_JS_DEFER, true );
232	$disable_js_delay = (bool) get_post_meta( get_the_ID(), POST_META_DISABLE_JS_DELAY, true );
233
234	if ( $disable_css_optimization ) {
235	add_filter( 'powered_cache_fo_css_do_concat', '__return_false' );
236	add_filter( 'powered_cache_fo_disable_css_minify', '__return_true' );
237	}
238
239	if ( $disable_js_optimization ) {
240	add_filter( 'powered_cache_fo_js_do_concat', '__return_false' );
241	add_filter( 'powered_cache_fo_disable_js_minify', '__return_true' );
242	}
243
244	if ( $disable_js_defer ) {
245	add_filter( 'powered_cache_disable_js_defer', '__return_true' );
246	add_filter( 'powered_cache_disable_js_defer_inline', '__return_true' );
247	}
248
249	if ( $disable_js_delay ) {
250	add_filter( 'powered_cache_delayed_js_skip', '__return_true' );
251	}
252	}
253	}
254
255	/**
256	* Purge FO cache
257	*
258	* @since 2.0
259	*/
260	public function maybe_purge_fo_cache() {
261	if ( file_exists( POWERED_CACHE_FO_CACHE_DIR ) ) {
262	remove_dir( POWERED_CACHE_FO_CACHE_DIR );
263	}
264	}
265
266	/**
267	* Minify given HTML output
268	*
269	* @param string $buffer HTML
270	*
271	* @return string\|string[]\|null
272	*/
273	public function maybe_minify_html( $buffer ) {
274	if ( ! $this->settings['minify_html'] ) {
275	return $buffer;
276	}
277
278	if ( false === stripos( $buffer, '<html' ) && false === stripos( $buffer, '<!DOCTYPE html' ) ) {
279	return $buffer;
280	}
281
282	/**
283	* Filters whether disable or not disable HTML minification.
284	*
285	* @hook powered_cache_fo_disable_html_minify
286	*
287	* @param {boolean} true to disable html minify
288	*
289	* @return {boolean} New value.
290	* @since 2.0
291	*/
292	if ( apply_filters( 'powered_cache_fo_disable_html_minify', false ) ) {
293	return $buffer;
294	}
295
296	$html_min = new HtmlMin();
297	$html_min->doOptimizeViaHtmlDomParser( $this->settings['minify_html_dom_optimization'] );
298	$html_min->doRemoveOmittedQuotes( false );
299	$html_min->doRemoveOmittedHtmlTags( false );
300	$html_min->overwriteSpecialScriptTags( [ 'x-tmpl-mustache', 'text/template' ] );
301	$buffer = $html_min->minify( $buffer );
302
303	if ( ! $this->settings['minify_html_dom_optimization'] ) {
304	// Remove line breaks and spaces between tags
305	$buffer = preg_replace( '/>\s+</', '><', $buffer );
306	// Remove comments
307	$buffer = preg_replace( '/<!--(.\|\s)*?-->/', '', $buffer );
308	}
309
310	return $buffer;
311	}
312
313
314	/**
315	* Add JS execution method to script tag
316	*
317	* @param string $tag <script... tag
318	*
319	* @return mixed
320	*/
321	public function change_js_execute_method( $tag ) {
322	$is_defer = $this->settings['js_defer'];
323
324	if ( ! $is_defer ) {
325	return $tag;
326	}
327
328	if ( preg_match( '/<script\s+[^>]\b(?:async\|defer)\b[^>]>/i', $tag ) ) {
329	return $tag;
330	}
331
332	if ( Helper::is_defer_excluded( $tag ) ) {
333	return $tag;
334	}
335
336	/**
337	* Filters whether disable or not disable Defer
338	*
339	* @hook powered_cache_disable_js_defer
340	*
341	* @param {boolean} true to disable defer
342	*
343	* @return {boolean} New value.
344	* @since 3.2
345	*/
346	if ( apply_filters( 'powered_cache_disable_js_defer', false, $tag ) ) {
347	return $tag;
348	}
349
350	$search = '<script ';
351	$replace = '<script defer="defer" ';
352	$tag = str_replace( $search, $replace, $tag );
353
354	return $tag;
355	}
356
357	/**
358	* Minify CSS item
359	*
360	* @param string $tag style tag <link...
361	* @param string $handle style handle name
362	* @param string $href Resource URL
363	* @param string $media CSS media
364	*
365	* @return mixed
366	*/
367	public function css_minify( $tag, $handle, $href, $media ) {
368	if ( ! $this->settings['minify_css'] ) {
369	return $tag;
370	}
371
372	/**
373	* Filters whether disable or not disable CSS minification.
374	*
375	* @hook powered_cache_fo_disable_css_minify
376	*
377	* @param {boolean} true to disable CSS minify
378	*
379	* @return {boolean} New value.
380	* @since 2.0
381	*/
382	if ( apply_filters( 'powered_cache_fo_disable_css_minify', false ) ) {
383	return $tag;
384	}
385
386	// only minify static .css
387	if ( false === strpos( $href, '.css' ) ) {
388	return $tag;
389	}
390
391	// already minified
392	if ( false !== strpos( $href, '.min' ) ) {
393	return $tag;
394	}
395
396	// only minify local hosted
397	if ( ! Helper::is_internal_url( $href, home_url() ) ) {
398	return $tag;
399	}
400
401	// excluded explicitly
402	if ( Helper::is_excluded_css( $href ) ) {
403	return $tag;
404	}
405
406	$realpath = Helper::realpath( $href, home_url() );
407	$path = substr( $realpath, strlen( ABSPATH ) - 1 );
408	$optimized_url = Helper::get_optimized_url( $path, true );
409	$new_tag = str_replace( $href, $optimized_url, $tag );
410
411	return $new_tag;
412	}
413
414	/**
415	* Minify JS file
416	*
417	* @param string $tag script tag <script...
418	* @param string $handle JS handle
419	* @param string $src Resource URL
420	*
421	* @return mixed
422	*/
423	public function js_minify( $tag, $handle, $src ) {
424	if ( ! $this->settings['minify_js'] ) {
425	return $tag;
426	}
427
428	/**
429	* Filters whether disable or not disable JS minification.
430	*
431	* @hook powered_cache_fo_disable_js_minify
432	*
433	* @param {boolean} true to disable JS minify
434	* @param {string} $tag script tag <script...
435	* @param {string} $handle JS handle
436	* @param {string} $src Resource URL
437	*
438	* @return {boolean} New value.
439	* @since 2.0
440	*/
441	if ( apply_filters( 'powered_cache_fo_disable_js_minify', false, $tag, $handle, $src ) ) {
442	return $tag;
443	}
444
445	// only minify static .css
446	if ( false === strpos( $src, '.js' ) ) {
447	return $tag;
448	}
449
450	// already minified
451	if ( false !== strpos( $src, '.min' ) ) {
452	return $tag;
453	}
454
455	// only minify local hosted
456	if ( ! Helper::is_internal_url( $src, home_url() ) ) {
457	return $tag;
458	}
459
460	// excluded explicitly
461	if ( Helper::is_excluded_js( $src ) ) {
462	return $tag;
463	}
464
465	$realpath = Helper::realpath( $src, home_url() );
466	$path = substr( $realpath, strlen( ABSPATH ) - 1 );
467	$optimized_url = Helper::get_optimized_url( $path, true );
468	$new_tag = str_replace( $src, $optimized_url, $tag );
469
470	return $new_tag;
471	}
472
473
474	/**
475	* Setup JS concat
476	*/
477	public function setup_js_combine() {
478	if ( ! $this->settings['combine_js'] ) {
479	return;
480	}
481
482	/**
483	* Filters whether disable or not disable JS combine
484	*
485	* @hook powered_cache_fo_disable_js_combine
486	*
487	* @param {boolean} true to disable JS combine
488	*
489	* @return {boolean} New value.
490	* @since 2.0
491	*/
492	if ( apply_filters( 'powered_cache_fo_disable_js_combine', false ) ) {
493	return;
494	}
495
496	global $wp_scripts;
497
498	$wp_scripts = new JS( $wp_scripts );
499	/**
500	* Filters whether allow or not allow gzip compression for combined file names.
501	*
502	* @hook powered_cache_fo_allow_gzip_compression
503	*
504	* @param {boolean} true to enable gzip compression on filenames
505	*
506	* @return {boolean} New value.
507	* @since 2.0
508	*/
509	$wp_scripts->allow_gzip_compression = apply_filters( 'powered_cache_fo_allow_gzip_compression', true );
510	$wp_scripts->do_minify = $this->settings['minify_js'];
511
512	}
513
514	/**
515	* Setup CSS concat
516	*/
517	public function setup_css_combine() {
518	if ( ! $this->settings['combine_css'] ) {
519	return;
520	}
521
522	/**
523	* Filters whether disable or not disable CSS combine
524	*
525	* @hook powered_cache_fo_disable_css_combine
526	*
527	* @param {boolean} true to disable CSS combine
528	*
529	* @return {boolean} New value.
530	* @since 2.0
531	*/
532	if ( apply_filters( 'powered_cache_fo_disable_css_combine', false ) ) {
533	return;
534	}
535
536	global $wp_styles;
537
538	$wp_styles = new CSS( $wp_styles );
539	$wp_styles->allow_gzip_compression = apply_filters( 'powered_cache_fo_allow_gzip_compression', true );
540	$wp_styles->do_minify = $this->settings['minify_css'];
541	$wp_styles->enable_cdn = $this->settings['enable_cdn'];
542
543	}
544
545	/**
546	* Combine google fonts
547	* Derived from https://gist.github.com/eugenealegiojo/dbdd620a998458aa2eb1f124b2f0b18e
548	*/
549	public function combine_google_fonts() {
550	global $wp_styles;
551
552	// Check for any enqueued `fonts.googleapis.com` from themes or plugins
553	if ( isset( $wp_styles->queue ) ) {
554	$google_fonts_domain = '//fonts.googleapis.com/css';
555	$enqueued_google_fonts = array();
556	$families = array();
557	$subsets = array();
558	$font_args = array();
559	$font_display = '';
560
561	// Collect all enqueued google fonts
562	foreach ( $wp_styles->queue as $key => $handle ) {
563	if ( ! isset( $wp_styles->registered[ $handle ] ) ) {
564	continue;
565	}
566
567	$style_src = $wp_styles->registered[ $handle ]->src;
568
569	if ( false !== strpos( $style_src, 'fonts.googleapis.com/css' ) \|\| false !== strpos( $style_src, 'fonts.bunny.net/css' ) ) {
570	$url = wp_parse_url( $style_src );
571
572	if ( is_string( $url['query'] ) ) {
573	parse_str( $url['query'], $parsed_url );
574
575	if ( isset( $parsed_url['family'] ) ) {
576	// Collect all subsets
577	if ( isset( $parsed_url['subset'] ) ) {
578	$subsets[] = rawurlencode( trim( $parsed_url['subset'] ) );
579	}
580
581	$font_families = explode( '\|', $parsed_url['family'] );
582	foreach ( $font_families as $parsed_font ) {
583	$get_font = explode( ':', $parsed_font );
584
585	// Extract the font data
586	if ( isset( $get_font[0] ) && ! empty( $get_font[0] ) ) {
587	$family = $get_font[0];
588	$weights = isset( $get_font[1] ) && ! empty( $get_font[1] ) ? explode( ',', $get_font[1] ) : array();
589
590	// Combine weights if family has been enqueued
591	if ( isset( $enqueued_google_fonts[ $family ] ) && $weights !== $enqueued_google_fonts[ $family ]['weights'] ) {
592	$combined_weights = array_merge( $weights, $enqueued_google_fonts[ $family ]['weights'] );
593	$enqueued_google_fonts[ $family ]['weights'] = array_unique( $combined_weights );
594	} else {
595	$enqueued_google_fonts[ $family ] = array(
596	'handle' => $handle,
597	'family' => $family,
598	'weights' => $weights,
599	);
600
601	if ( isset( $parsed_url['display'] ) ) {
602	$font_display = $parsed_url['display'];
603	}
604
605	// Remove enqueued google font style, so we would only have one HTTP request.
606	wp_dequeue_style( $handle );
607	}
608	}
609	}
610	}
611	}
612	}
613	}
614
615	// Combine all queued fonts
616	if ( count( $enqueued_google_fonts ) > 0 ) {
617	foreach ( $enqueued_google_fonts as $family => $data ) {
618	// Collect all family and weights
619	if ( ! empty( $data['weights'] ) ) {
620	$families[] = $family . ':' . implode( ',', $data['weights'] );
621	} else {
622	$families[] = $family;
623	}
624	}
625
626	if ( ! empty( $families ) ) {
627	$font_args['family'] = implode( '\|', $families );
628
629	if ( ! empty( $subsets ) ) {
630	$font_args['subset'] = implode( ',', $subsets );
631	}
632
633	/**
634	* Force font display: swap
635	*
636	* @since 2.2
637	*/
638	if ( $this->settings['swap_google_fonts_display'] ) {
639	$font_display = 'swap';
640	}
641
642	/**
643	* Filters font display attribute of the google fonts.
644	*
645	* @hook powered_cache_fo_google_font_display
646	*
647	* @param {string} $font_display font display attribute.
648	*
649	* @return {string} New value.
650	* @since 2.0
651	*/
652	$font_display = apply_filters( 'powered_cache_fo_google_font_display', $font_display );
653
654	if ( ! empty( $font_display ) ) {
655	$font_args['display'] = $font_display;
656	}
657
658	/**
659	* Filters google font's domain
660	*
661	* @hook powered_cache_fo_google_fonts_domain
662	*
663	* @param {string} $font_display font display attribute.
664	*
665	* @return {string} New value.
666	* @since 3.0
667	*/
668	$fonts_domain = apply_filters( 'powered_cache_fo_google_fonts_domain', $google_fonts_domain );
669
670	$src = esc_url_raw( add_query_arg( $font_args, $fonts_domain ) );
671
672	// Enqueue google fonts into one URL request
673	wp_enqueue_style( // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion
674	'pc-google-fonts-' . md5( $src ),
675	$src,
676	array()
677	);
678
679	unset( $enqueued_google_fonts );
680	}
681	}
682	}
683	}
684
685	/**
686	* DelayedJS execution
687	* Similar logic with image lazy-loading but this time for scripts.
688	*
689	* @param string $html HTML Buffer
690	*
691	* @return string
692	* @since 3.0
693	*/
694	public function maybe_delay_scripts( $html ) {
695	if ( ! $this->settings['js_delay'] ) {
696	return $html;
697	}
698
699	$pattern = '/<script([^>])>(.?)<\/script>/si';
700
701	preg_match_all( $pattern, $html, $matches, PREG_SET_ORDER );
702
703	if ( empty( $matches ) ) {
704	return $html;
705	}
706
707	$delayed_script_count = 0;
708
709	foreach ( $matches as $match ) {
710	$script = $match[0];
711	$attributes = $match[1];
712	$content = $match[2];
713
714	$is_delay_skipped = function_exists( 'is_user_logged_in' ) && is_user_logged_in();
715
716	/**
717	* Whether skip or not skip js for delay
718	*
719	* @hook powered_cache_delayed_js_skip
720	*
721	* @param {bool} Depends on logged-in status by default.
722	*
723	* @return {bool} New value.
724	* @since 3.0
725	*/
726	if ( apply_filters( 'powered_cache_delayed_js_skip', $is_delay_skipped, $script, $attributes, $content ) ) {
727	continue;
728	}
729
730	if ( Helper::is_delay_excluded( $script ) ) {
731	continue;
732	}
733
734	if ( ! preg_match( '/type=/', $script ) \|\| preg_match( '/type=[\'"]text\/javascript[\'"]/', $script ) ) {
735	$new_script = $script;
736
737	// Check if script has a src attribute
738	if ( strpos( $attributes, 'src=' ) !== false ) {
739	$new_script = preg_replace( '/<script([^>]*)>/', '<script type="pc-delayed-js"$1>', $new_script );
740	} else {
741	$new_script = preg_replace( '/<script([^>]*)>/', '<script type="pc-delayed-js"$1>', $new_script );
742	}
743
744	$html = str_replace( $script, $new_script, $html );
745	$delayed_script_count ++;
746	}
747	}
748
749	if ( 0 === $delayed_script_count ) {
750	return $html;
751	}
752
753	/**
754	* Filter delay time for JS execution fallback
755	*
756	* @hook powered_cache_delayed_js_timeout
757	*
758	* @param {int} $delay_in_ms Delay time in milliseconds
759	*
760	* @return {int} New value.
761	* @since 3.0
762	*/
763	$delay_timeout = apply_filters( 'powered_cache_delayed_js_timeout', $this->settings['js_delay_timeout'] );
764	$script_path = POWERED_CACHE_PATH . 'dist/js/script-loader.js';
765	$script_content = file_get_contents( $script_path ); // phpcs:ignore
766
767	if ( ! $script_content ) {
768	return $html;
769	}
770
771	$head_pos = strpos( $html, '</head>' );
772
773	if ( false === $head_pos ) { // bail if no head tag
774	return $html;
775	}
776
777	$delay_js_script_content = '<script id="powered-cache-delayed-js">' . $script_content . '</script>' . PHP_EOL;
778
779	/**
780	* Delayed JS script content
781	*
782	* @hook powered_cache_delayed_js_script_content
783	*
784	* @param {string} $delay_js_script_content Delayed JS script content
785	* @param {string} $script_path Script path
786	* @param {string} $html HTML buffer
787	* @param {int} $delay_timeout Delay time in milliseconds
788	*
789	* @return {string} New value.
790	* @since 3.4
791	*/
792	$delay_js_script_content = apply_filters( 'powered_cache_delayed_js_script_content', $delay_js_script_content, $script_path, $html, $delay_timeout );
793
794	$html = substr_replace( $html, $delay_js_script_content, $head_pos, 0 );
795
796	$script_loader = PHP_EOL . '<script id="powered-cache-delayed-script-loader">' . PHP_EOL;
797	$script_loader .= 'console.log("[Powered Cache] - Script(s) will be loaded with delay or interaction");' . PHP_EOL;
798	$script_loader .= 'window.PCScriptLoaderTimeout=' . absint( $delay_timeout ) . ';' . PHP_EOL;
799
800	$script_loader .= 'Defer.all(\'script[type="pc-delayed-js"]\', window.PCScriptLoaderTimeout, true);' . PHP_EOL;
801
802	// Dispatch DOMContentLoaded event after delayed scripts are loaded
803	// This ensures scripts that listen for DOMContentLoaded still execute
804	$script_loader .= '(function(){' . PHP_EOL;
805	$script_loader .= ' var pcDelayedScripts=document.querySelectorAll(\'script[type="pc-delayed-js"]\');' . PHP_EOL;
806	$script_loader .= ' if(pcDelayedScripts.length===0)return;' . PHP_EOL;
807	$script_loader .= ' var pcScriptCount=pcDelayedScripts.length;' . PHP_EOL;
808	$script_loader .= ' var pcCheckInterval=setInterval(function(){' . PHP_EOL;
809	$script_loader .= ' var remaining=document.querySelectorAll(\'script[type="pc-delayed-js"]\').length;' . PHP_EOL;
810	$script_loader .= ' if(remaining===0){' . PHP_EOL;
811	$script_loader .= ' clearInterval(pcCheckInterval);' . PHP_EOL;
812	$script_loader .= ' setTimeout(function(){' . PHP_EOL;
813	$script_loader .= ' if(document.readyState==="complete"\|\|document.readyState==="interactive"){' . PHP_EOL;
814	$script_loader .= ' var event=document.createEvent?document.createEvent("Event"):new Event("DOMContentLoaded");' . PHP_EOL;
815	$script_loader .= ' if(document.createEvent){event.initEvent("DOMContentLoaded",true,true);}' . PHP_EOL;
816	$script_loader .= ' document.dispatchEvent(event);' . PHP_EOL;
817	$script_loader .= ' console.log("[Powered Cache] - DOMContentLoaded event dispatched for "+pcScriptCount+" delayed script(s)");' . PHP_EOL;
818	$script_loader .= ' }' . PHP_EOL;
819	$script_loader .= ' },10);' . PHP_EOL;
820	$script_loader .= ' }' . PHP_EOL;
821	$script_loader .= ' },50);' . PHP_EOL;
822	$script_loader .= '})();' . PHP_EOL;
823
824	$script_loader .= '</script>' . PHP_EOL;
825
826	/**
827	* Delayed JS script loader content
828	*
829	* @hook powered_cache_delayed_js_script_loader
830	*
831	* @param {string} $script_loader Delayed JS script loader content
832	* @param {string} $html HTML buffer
833	* @param {int} $delay_timeout Delay time in milliseconds
834	*
835	* @return {string} New value.
836	* @since 3.4
837	*/
838	$script_loader = apply_filters( 'powered_cache_delayed_js_script_loader', $script_loader, $html, $delay_timeout );
839
840	$body_pos = strpos( $html, '</body>' );
841
842	if ( false !== $body_pos ) {
843	$html = substr_replace( $html, $script_loader, $body_pos, 0 );
844	} else {
845	$html_pos = strpos( $html, '</html>' );
846	if ( false !== $html_pos ) {
847	$html = substr_replace( $html, $script_loader, $html_pos, 0 );
848	}
849	}
850
851	return $html;
852	}
853
854	/**
855	* Defer jQuery depended inline scripts
856	*
857	* @param string $html Output buffer
858	*
859	* @return array\|mixed\|string\|string[]\|null
860	* @since 3.2
861	*/
862	public function maybe_defer_inline_scripts( $html ) {
863	if ( ! $this->settings['js_defer'] ) {
864	return $html;
865	}
866
867	$html = preg_replace_callback(
868	'/(<script[^>]>)(.?)<\/script>/s',
869	function ( $matches ) {
870	$script_open_tag = $matches[1];
871	$script_content = $matches[2];
872
873	if ( ! $this->should_defer_script( $script_content, $script_open_tag ) ) {
874	return $matches[0]; // Return the script unchanged
875	}
876
877	/**
878	* Filters whether disable or not disable inline defer
879	*
880	* @hook powered_cache_disable_js_defer_inline
881	*
882	* @param {boolean} true to disable defer
883	*
884	* @return {boolean} New value.
885	* @since 3.2
886	*/
887	if ( apply_filters( 'powered_cache_disable_js_defer_inline', false, $script_content, $script_open_tag ) ) {
888	return $matches[0]; // Return the script unchanged
889	}
890
891	return $script_open_tag . 'window.addEventListener("DOMContentLoaded", function() {(function($) {' . $script_content . '})(jQuery);});</script>';
892	},
893	$html
894	);
895
896	return $html;
897	}
898
899	/**
900	* Determine whether defer or not defer inline script
901	*
902	* @param string $script_content Script content
903	* @param string $script_attributes Script attributes
904	*
905	* @return bool
906	* @since 3.2
907	*/
908	private function should_defer_script( $script_content, $script_attributes ) {
909	// Ignore scripts with a 'src' attribute (external scripts)
910	if ( false !== strpos( $script_attributes, 'src=' ) ) {
911	return false;
912	}
913
914	// ignore ld+json
915	if ( false !== strpos( $script_attributes, 'type="application/ld+json"' ) ) {
916	return false;
917	}
918
919	// Check if the script contains 'DOMContentLoaded' or 'document.write'
920	if ( false !== strpos( $script_content, 'DOMContentLoaded' ) \|\| false !== strpos( $script_content, 'document.write' ) ) {
921	return false;
922	}
923
924	// Check if the script does NOT contain jQuery-related functions
925	if ( false === strpos( $script_content, 'jQuery(' ) && false === strpos( $script_content, '$.(' ) && false === strpos( $script_content, '$(' ) ) {
926	return false;
927	}
928
929	return true;
930	}
931
932
933	}
934