optimole-wp / inc / lazyload_replacer.php

lazyload_replacer.php in Optimole – Optimize Images | Convert WebP & AVIF | CDN & Lazy Load | Image Optimization 3.11.1, at inc/lazyload_replacer.php

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1	<?php
2
3	/**
4	* The class handles the img tag replacements for lazyload.
5	*
6	* @package \Optml\Inc
7	* @author Optimole <friends@optimole.com>
8	*/
9	final class Optml_Lazyload_Replacer extends Optml_App_Replacer {
10	use Optml_Normalizer;
11	use Optml_Validator;
12
13	const IFRAME_PLACEHOLDER_CLASS = '
14	iframe[data-opt-src]:not([data-opt-lazy-loaded]) {
15	background-color: #ffffff;
16	background-image: url("data:image/svg+xml,%3Csvg%20width%3D%2240%22%20height%3D%2240%22%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20style%3D%22-webkit-transform-origin%3A50%25%2050%25%3B-webkit-animation%3Aspin%201.5s%20linear%20infinite%3B-webkit-backface-visibility%3Ahidden%3Banimation%3Aspin%201.5s%20linear%20infinite%22%20fill-rule%3D%22evenodd%22%20clip-rule%3D%22evenodd%22%20stroke-linejoin%3D%22round%22%20stroke-miterlimit%3D%221.414%22%3E%3Cdefs%3E%3Cstyle%3E%3C%21%5BCDATA%5B%40-webkit-keyframes%20spin%7Bfrom%7B-webkit-transform%3Arotate%280deg%29%7Dto%7B-webkit-transform%3Arotate%28-359deg%29%7D%7D%40keyframes%20spin%7Bfrom%7Btransform%3Arotate%280deg%29%7Dto%7Btransform%3Arotate%28-359deg%29%7D%7D%5D%5D%3E%3C%2Fstyle%3E%3C%2Fdefs%3E%3Cg%20id%3D%22outer%22%3E%3Cpath%20d%3D%22M20%200a3.994%203.994%200%20110%207.988A3.994%203.994%200%200120%200z%22%2F%3E%3Cpath%20d%3D%22M5.858%205.858a3.994%203.994%200%20115.648%205.648%203.994%203.994%200%2001-5.648-5.648z%22%20fill%3D%22%23d2d2d2%22%2F%3E%3Cpath%20d%3D%22M20%2032.012A3.994%203.994%200%201120%2040a3.994%203.994%200%20010-7.988z%22%20fill%3D%22%23828282%22%2F%3E%3Cpath%20d%3D%22M28.494%2028.494a3.994%203.994%200%20115.648%205.648%203.994%203.994%200%2001-5.648-5.648z%22%20fill%3D%22%23656565%22%2F%3E%3Cpath%20d%3D%22M3.994%2016.006a3.994%203.994%200%20110%207.988%203.994%203.994%200%20010-7.988z%22%20fill%3D%22%23bbb%22%2F%3E%3Cpath%20d%3D%22M5.858%2028.494a3.994%203.994%200%20115.648%205.648%203.994%203.994%200%2001-5.648-5.648z%22%20fill%3D%22%23a4a4a4%22%2F%3E%3Cpath%20d%3D%22M36.006%2016.006a3.994%203.994%200%20110%207.988%203.994%203.994%200%20010-7.988z%22%20fill%3D%22%234a4a4a%22%2F%3E%3Cpath%20d%3D%22M28.494%205.858a3.994%203.994%200%20115.648%205.648%203.994%203.994%200%2001-5.648-5.648z%22%20fill%3D%22%23323232%22%2F%3E%3C%2Fg%3E%3C%2Fsvg%3E");
17	background-repeat: no-repeat;
18	background-position: 50% 50%;
19	}
20	video[data-opt-src]:not([data-opt-lazy-loaded]) {
21	background-color: #ffffff;
22	background-image: url("data:image/svg+xml,%3Csvg%20width%3D%2240%22%20height%3D%2240%22%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20style%3D%22-webkit-transform-origin%3A50%25%2050%25%3B-webkit-animation%3Aspin%201.5s%20linear%20infinite%3B-webkit-backface-visibility%3Ahidden%3Banimation%3Aspin%201.5s%20linear%20infinite%22%20fill-rule%3D%22evenodd%22%20clip-rule%3D%22evenodd%22%20stroke-linejoin%3D%22round%22%20stroke-miterlimit%3D%221.414%22%3E%3Cdefs%3E%3Cstyle%3E%3C%21%5BCDATA%5B%40-webkit-keyframes%20spin%7Bfrom%7B-webkit-transform%3Arotate%280deg%29%7Dto%7B-webkit-transform%3Arotate%28-359deg%29%7D%7D%40keyframes%20spin%7Bfrom%7Btransform%3Arotate%280deg%29%7Dto%7Btransform%3Arotate%28-359deg%29%7D%7D%5D%5D%3E%3C%2Fstyle%3E%3C%2Fdefs%3E%3Cg%20id%3D%22outer%22%3E%3Cpath%20d%3D%22M20%200a3.994%203.994%200%20110%207.988A3.994%203.994%200%200120%200z%22%2F%3E%3Cpath%20d%3D%22M5.858%205.858a3.994%203.994%200%20115.648%205.648%203.994%203.994%200%2001-5.648-5.648z%22%20fill%3D%22%23d2d2d2%22%2F%3E%3Cpath%20d%3D%22M20%2032.012A3.994%203.994%200%201120%2040a3.994%203.994%200%20010-7.988z%22%20fill%3D%22%23828282%22%2F%3E%3Cpath%20d%3D%22M28.494%2028.494a3.994%203.994%200%20115.648%205.648%203.994%203.994%200%2001-5.648-5.648z%22%20fill%3D%22%23656565%22%2F%3E%3Cpath%20d%3D%22M3.994%2016.006a3.994%203.994%200%20110%207.988%203.994%203.994%200%20010-7.988z%22%20fill%3D%22%23bbb%22%2F%3E%3Cpath%20d%3D%22M5.858%2028.494a3.994%203.994%200%20115.648%205.648%203.994%203.994%200%2001-5.648-5.648z%22%20fill%3D%22%23a4a4a4%22%2F%3E%3Cpath%20d%3D%22M36.006%2016.006a3.994%203.994%200%20110%207.988%203.994%203.994%200%20010-7.988z%22%20fill%3D%22%234a4a4a%22%2F%3E%3Cpath%20d%3D%22M28.494%205.858a3.994%203.994%200%20115.648%205.648%203.994%203.994%200%2001-5.648-5.648z%22%20fill%3D%22%23323232%22%2F%3E%3C%2Fg%3E%3C%2Fsvg%3E");
23	background-repeat: no-repeat;
24	background-position: 50% 50%;
25	}';
26	const IFRAME_PLACEHOLDER_STYLE = '<style type="text/css">' . self::IFRAME_PLACEHOLDER_CLASS . '</style>';
27
28	const IFRAME_TEMP_COMMENT = '/** optmliframelazyloadplaceholder */';
29
30	const SVG_PLACEHOLDER = 'data:image/svg+xml,%3Csvg%20viewBox%3D%220%200%20#width#%20#height#%22%20width%3D%22#width#%22%20height%3D%22#height#%22%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%3E%3Crect%20width%3D%22#width#%22%20height%3D%22#height#%22%20fill%3D%22#fill#%22%2F%3E%3C%2Fsvg%3E';
31	/**
32	* If frame lazyload is present on page.
33	*
34	* @var bool Whether or not at least one iframe has been lazyloaded.
35	*/
36	private static $found_iframe = false;
37	/**
38	* Cached object instance.
39	*
40	* @var Optml_Lazyload_Replacer
41	*/
42	protected static $instance = null;
43	/**
44	* Holds the number of images to skip from lazyload.
45	*
46	* @var integer The number image tags to skip.
47	*/
48	private static $skip_lazyload_images = null;
49	/**
50	* Holds classes for listening to lazyload on background.
51	*
52	* @var array Lazyload background classes.
53	*/
54	private static $lazyload_background_classes = null;
55	/**
56	* Selectors used for background lazyload.
57	*
58	* @var array Lazyload background CSS selectors.
59	*/
60	private static $background_lazyload_selectors = null;
61	/**
62	* Holds flags which remove noscript tag bundle causing issues on render, i.e slider plugins.
63	*
64	* @var array Noscript flags.
65	*/
66	private static $ignore_no_script_flags = null;
67	/**
68	* Holds possible iframe lazyload flags where we should ignore our lazyload.
69	*
70	* @var array
71	*/
72	protected static $iframe_lazyload_flags = null;
73	/**
74	* Holds classes responsabile for watching lazyload behaviour.
75	*
76	* @var array Lazyload classes.
77	*/
78	private static $lazyload_watcher_classes = null;
79	/**
80	* Should we use the generic placeholder?
81	*
82	* @var bool Lazyload placeholder flag.
83	*/
84	private static $is_lazyload_placeholder = false;
85
86	/**
87	* Class instance method.
88	*
89	* @codeCoverageIgnore
90	* @static
91	* @return Optml_Lazyload_Replacer
92	* @since 1.0.0
93	* @access public
94	*/
95	public static function instance() {
96	if ( null === self::$instance ) {
97	self::$instance = new self();
98	add_action( 'optml_replacer_setup', [ self::$instance, 'init' ] );
99	}
100
101	return self::$instance;
102	}
103
104	/**
105	* Return lazyload selectors for background images.
106	*
107	* @return array Lazyload selectors.
108	*/
109	public static function get_background_lazyload_selectors() {
110	if ( null !== self::$background_lazyload_selectors ) {
111	return self::$background_lazyload_selectors;
112	}
113
114	if ( self::instance()->settings->get( 'bg_replacer' ) === 'disabled' ) {
115	self::$background_lazyload_selectors = [];
116	return self::$background_lazyload_selectors;
117	}
118	$default_watchers = [
119	'.elementor-section[data-settings*="background_background"]',
120	'.elementor-section > .elementor-background-overlay',
121	'[class="wp-block-cover"][style="background-image"]',
122	];
123
124	$saved_watchers = self::instance()->settings->get_watchers();
125
126	$saved_watchers = str_replace( [ "\n", "\r" ], ',', $saved_watchers );
127	$saved_watchers = explode( ',', $saved_watchers );
128	$all_watchers = array_merge( $default_watchers, $saved_watchers );
129	$all_watchers = apply_filters( 'optml_lazyload_bg_selectors', $all_watchers );
130	$all_watchers = array_filter(
131	$all_watchers,
132	function ( $value ) {
133	return ! empty( $value ) && strlen( $value ) >= 2;
134	}
135	);
136
137	self::$background_lazyload_selectors = $all_watchers;
138
139	return self::$background_lazyload_selectors;
140	}
141
142	/**
143	* Returns background classes for lazyload.
144	*
145	* @return array
146	*/
147	public static function get_lazyload_bg_classes() {
148	if ( null !== self::$lazyload_background_classes ) {
149	return self::$lazyload_background_classes;
150	}
151
152	self::$lazyload_background_classes = apply_filters( 'optml_lazyload_bg_classes', [] );
153
154	return self::$lazyload_background_classes;
155	}
156	/**
157	* Returns the number of images to skip from lazyload.
158	*
159	* @return integer
160	*/
161	public static function get_skip_lazyload_limit() {
162
163	if ( self::$skip_lazyload_images !== null ) {
164	return self::$skip_lazyload_images;
165	}
166	self::$skip_lazyload_images = apply_filters( 'optml_lazyload_images_skip', self::instance()->settings->get( 'skip_lazyload_images' ) );
167	return self::$skip_lazyload_images;
168	}
169	/**
170	* Returns classes for lazyload additional watch.
171	*
172	* @return array
173	*/
174	public static function get_watcher_lz_classes() {
175	if ( null !== self::$lazyload_watcher_classes ) {
176	return self::$lazyload_watcher_classes;
177	}
178
179	self::$lazyload_watcher_classes = apply_filters( 'optml_watcher_lz_classes', [] );
180
181	return self::$lazyload_watcher_classes;
182	}
183
184	/**
185	* The initialize method.
186	*/
187	public function init() {
188	parent::init();
189
190	if ( ! $this->settings->use_lazyload() ) {
191	return;
192	}
193	$filters = $this->settings->get_filters();
194	if ( ! Optml_Filters::should_do_page( $filters[ Optml_Settings::FILTER_TYPE_LAZYLOAD ][ Optml_Settings::FILTER_URL ], $filters[ Optml_Settings::FILTER_TYPE_LAZYLOAD ][ Optml_Settings::FILTER_URL_MATCH ] ) ) {
195	return;
196	}
197
198	add_filter(
199	'max_srcset_image_width',
200	function () {
201	return 1;
202	}
203	);
204	self::$is_lazyload_placeholder = self::$instance->settings->get( 'lazyload_placeholder' ) === 'enabled';
205
206	add_filter( 'optml_tag_replace', [ $this, 'lazyload_tag_replace' ], 2, 6 );
207
208	add_filter( 'optml_video_replace', [$this, 'lazyload_video_replace'], 2, 1 );
209
210	}
211	/**
212	* Check if there are lazyloaded iframes.
213	*
214	* @return bool Whether an iframe was lazyloaded on the page or not.
215	*/
216	public static function found_iframe() {
217	return self::$found_iframe;
218	}
219
220	/**
221	* Check if the img tag should be lazyloaded early.
222	*
223	* @param string $image_tag The image tag.
224	* @return bool Whether the image tag should be lazyloaded early or not.
225	*/
226	public function should_lazyload_early( $image_tag ) {
227	$flags = apply_filters( 'optml_lazyload_early_flags', [] );
228
229	foreach ( $flags as $flag ) {
230	if ( strpos( $image_tag, $flag ) !== false ) {
231	return true;
232	}
233	}
234
235	return false;
236	}
237	/**
238	* Replaces the tags with lazyload tags.
239	*
240	* @param string $new_tag The new tag.
241	* @param string $original_url The original URL.
242	* @param string $new_url The optimized URL.
243	* @param array $optml_args Options passed for URL optimization.
244	* @param bool $is_slashed If the url needs slashes.
245	* @param string $full_tag Full tag, wrapper included.
246	*
247	* @return string
248	*/
249	public function lazyload_tag_replace( $new_tag, $original_url, $new_url, $optml_args, $is_slashed = false, $full_tag = '' ) {
250
251	if ( ! $this->can_lazyload_for( $original_url, $full_tag ) ) {
252	return Optml_Tag_Replacer::instance()->regular_tag_replace( $new_tag, $original_url, $new_url, $optml_args, $is_slashed );
253	}
254
255	if ( self::instance()->settings->get( 'native_lazyload' ) === 'enabled' ) {
256	if ( strpos( $new_tag, 'loading=' ) === false ) {
257	$new_tag = preg_replace( '/<img/im', $is_slashed ? '<img loading=\"lazy\"' : '<img loading="lazy"', $new_tag );
258	}
259	return $new_tag;
260	}
261
262	$should_ignore_rescale = ! $this->is_valid_mimetype_from_url( $original_url, [ 'gif' => true, 'svg' => true ] );
263
264	if ( ! self::$is_lazyload_placeholder && ! $should_ignore_rescale ) {
265	$optml_args['quality'] = 'eco';
266	$optml_args['resize'] = [];
267	$low_url = apply_filters( 'optml_content_url', $original_url, $optml_args );
268	$low_url = $is_slashed ? addcslashes( $low_url, '/' ) : $low_url;
269	} else {
270	$low_url = $this->get_svg_for(
271	isset( $optml_args['width'] ) ? $optml_args['width'] : '100%',
272	isset( $optml_args['height'] ) ? $optml_args['height'] : '100%',
273	( $should_ignore_rescale ? null : $original_url )
274	);
275	}
276
277	$opt_format = '';
278
279	if ( $this->should_add_data_tag( $full_tag ) ) {
280	$opt_format = ' data-opt-src="%s" ';
281	$custom_class = '';
282
283	if ( $should_ignore_rescale ) {
284	$custom_class .= 'optimole-lazy-only ';
285	}
286	if ( $this->should_lazyload_early( $full_tag ) ) {
287	$custom_class .= 'optimole-load-early';
288	}
289
290	if ( ! empty( $custom_class ) ) {
291	if ( strpos( $new_tag, 'class=' ) === false ) {
292	$opt_format .= ' class="' . $custom_class . '" ';
293	} else {
294	$new_tag = str_replace(
295	( $is_slashed ? 'class=\"' : 'class="' ),
296	( $is_slashed ? 'class=\"' . $custom_class . ' ' : 'class="' . $custom_class . ' ' ),
297	$new_tag
298	);
299	}
300	}
301	$opt_format = $is_slashed ? addslashes( $opt_format ) : $opt_format;
302	}
303	$new_url = $is_slashed ? addcslashes( $new_url, '/' ) : $new_url;
304
305	$opt_src = sprintf( $opt_format, $new_url );
306
307	$no_script_tag = str_replace(
308	$original_url,
309	$new_url,
310	$new_tag
311	);
312	$new_tag = preg_replace(
313	[
314	'/((?:\s\|\'\|"){1,}src(?>=\|"\|\'\|\s\|\\\\)*)' . preg_quote( $original_url, '/' ) . '/m',
315	'/<img/im',
316	],
317	[
318	"$1$low_url",
319	'<img' . $opt_src,
320	],
321	$new_tag,
322	1
323	);
324	$new_tag = str_replace( 'srcset=', 'old-srcset=', $new_tag );
325
326	if ( ! $this->should_add_noscript( $new_tag ) ) {
327	return $new_tag;
328	}
329
330	return $new_tag . '<noscript>' . $no_script_tag . '</noscript>';
331	}
332	/**
333	* Replaces video embeds with lazyload embeds.
334	*
335	* @param string $content Html page content.
336	*
337	* @return string
338	*/
339	public function lazyload_video_replace( $content ) {
340	$video_tags = [];
341	$iframes = [];
342	$videos = [];
343	preg_match_all( '#(?:<noscript\s>\s)?<iframe(.?)></iframe>(?:\s</noscript\s*>)?#is', $content, $iframes );
344	preg_match_all( '#(?:<noscript\s>\s)?<video(.?)>.?</video>(?:\s</noscript\s>)?#is', $content, $videos );
345	$video_tags = array_merge( $iframes[0], $videos[0] );
346
347	$search = [];
348	$replace = [];
349
350	foreach ( $video_tags as $video_tag ) {
351
352	if ( ! $this->should_lazyload_iframe( $video_tag ) ) {
353	continue;
354	}
355	if ( preg_match( "/ data-opt-src=['\"]/is", $video_tag ) ) {
356	continue;
357	}
358	$should_add_noscript = true;
359	$original_tag = $video_tag;
360	// replace the src and add the data-opt-src attribute
361	if ( strpos( $video_tag, 'iframe' ) !== false ) {
362	$video_tag = preg_replace( '/iframe(.*?)src=/is', 'iframe$1 src="about:blank" data-opt-src=', $video_tag );
363	} elseif ( strpos( $video_tag, 'video' ) !== false ) {
364	if ( strpos( $video_tag, 'source' ) !== false ) {
365	if ( strpos( $video_tag, 'preload' ) === false ) {
366	$video_tag = preg_replace( '/video(.*?)>/is', 'video$1 preload="metadata">', $video_tag, 1 );
367	$should_add_noscript = false;
368	} else {
369	continue;
370	}
371	} else {
372	$video_tag = preg_replace( '/video(.*?)src=/is', 'video$1 data-opt-src=', $video_tag );
373	}
374	}
375	if ( $this->should_add_noscript( $video_tag ) && $should_add_noscript ) {
376	$video_tag .= '<noscript>' . $original_tag . '</noscript>';
377	}
378	array_push( $search, $original_tag );
379	array_push( $replace, $video_tag );
380	self::$found_iframe = true;
381	}
382	$search = array_unique( $search );
383	$replace = array_unique( $replace );
384	$content = str_replace( $search, $replace, $content );
385	return $content;
386	}
387
388	/**
389	* Check if the lazyload is allowed for this url.
390	*
391	* @param string $url Url.
392	* @param string $tag Html tag.
393	*
394	* @return bool We can lazyload?
395	*/
396	public function can_lazyload_for( $url, $tag = '' ) {
397	foreach ( self::possible_lazyload_flags() as $banned_string ) {
398	if ( strpos( $tag, $banned_string ) !== false ) {
399	return false;
400	}
401	}
402	if ( false === Optml_Filters::should_do_image( $url, self::$filters[ Optml_Settings::FILTER_TYPE_LAZYLOAD ][ Optml_Settings::FILTER_FILENAME ] ) ) {
403	return false;
404	}
405	$url = strtok( $url, '?' );
406
407	$type = wp_check_filetype(
408	basename( $url ),
409	Optml_Config::$image_extensions
410	);
411
412	if ( empty( $type['ext'] ) ) {
413	return false;
414	}
415
416	if ( false === Optml_Filters::should_do_extension( self::$filters[ Optml_Settings::FILTER_TYPE_LAZYLOAD ][ Optml_Settings::FILTER_EXT ], $type['ext'] ) ) {
417	return false;
418	}
419
420	if ( defined( 'OPTML_DISABLE_PNG_LAZYLOAD' ) && OPTML_DISABLE_PNG_LAZYLOAD ) {
421	return $type['ext'] !== 'png';
422	}
423	if ( Optml_Tag_Replacer::$lazyload_skipped_images < self::get_skip_lazyload_limit() ) {
424	return false;
425	}
426	return true;
427	}
428
429	/**
430	* Check if we should add the data-opt-tag.
431	*
432	* @param string $tag Html tag.
433	*
434	* @return bool Should add?
435	*/
436	public function should_add_data_tag( $tag ) {
437	foreach ( self::possible_data_ignore_flags() as $banned_string ) {
438	if ( strpos( $tag, $banned_string ) !== false ) {
439	return false;
440	}
441	}
442
443	return true;
444	}
445
446	/**
447	* Get SVG markup with specific width/height.
448	*
449	* @param int\|string $width Markup Width.
450	* @param int\|string $height Markup Height.
451	* @param string\|null $url Original URL.
452	*
453	* @return string SVG code.
454	*/
455	public function get_svg_for( $width, $height, $url = null ) {
456
457	if ( $url !== null && ! is_numeric( $width ) ) {
458	$url = strtok( $url, '?' );
459	$key = crc32( $url );
460	$sizes = wp_cache_get( $key, 'optml_sources' );
461	if ( $sizes === false ) {
462	$filepath = substr( $url, strpos( $url, $this->upload_resource['content_folder'] ) + $this->upload_resource['content_folder_length'] );
463	$filepath = WP_CONTENT_DIR . $filepath;
464	if ( is_file( $filepath ) ) {
465	$sizes = getimagesize( $filepath );
466	wp_cache_add( $key, [ $sizes[0], $sizes[1] ], 'optml_sources', DAY_IN_SECONDS );
467	}
468	}
469	list( $width, $height ) = $sizes;
470	}
471
472	$width = ! is_numeric( $width ) ? '100%' : $width;
473	$height = ! is_numeric( $height ) ? '100%' : $height;
474	$fill = $this->settings->get( 'placeholder_color' );
475
476	if ( empty( $fill ) ) {
477	$fill = 'transparent';
478	}
479
480	return
481	str_replace(
482	[ '#width#', '#height#', '#fill#' ],
483	[
484	$width,
485	$height,
486	urlencode( $fill ),
487	],
488	self::SVG_PLACEHOLDER
489	);
490	}
491
492	/**
493	* Check if we should add the noscript tag.
494	*
495	* @param string $tag Html tag.
496	*
497	* @return bool Should add?
498	*/
499	public function should_add_noscript( $tag ) {
500	if ( $this->settings->get( 'no_script' ) === 'disabled' ) {
501	return false;
502	}
503	foreach ( self::get_ignore_noscript_flags() as $banned_string ) {
504	if ( strpos( $tag, $banned_string ) !== false ) {
505	return false;
506	}
507	}
508
509	return true;
510	}
511	/**
512	* Check if we should lazyload iframe.
513	*
514	* @param string $tag Html tag.
515	*
516	* @return bool Should add?
517	*/
518	public function should_lazyload_iframe( $tag ) {
519
520	foreach ( self::get_iframe_lazyload_flags() as $banned_string ) {
521	if ( strpos( $tag, $banned_string ) !== false ) {
522	return false;
523	}
524	}
525
526	return true;
527	}
528
529	/**
530	* Returns flags for ignoring noscript tag additional watch.
531	*
532	* @return array
533	*/
534	public static function get_ignore_noscript_flags() {
535	if ( null !== self::$ignore_no_script_flags ) {
536	return self::$ignore_no_script_flags;
537	}
538
539	self::$ignore_no_script_flags = apply_filters( 'optml_ignore_noscript_on', [] );
540
541	return self::$ignore_no_script_flags;
542	}
543	/**
544	* Returns possible lazyload flags for iframes.
545	*
546	* @return array
547	*/
548	public static function get_iframe_lazyload_flags() {
549	if ( null !== self::$iframe_lazyload_flags ) {
550	return self::$iframe_lazyload_flags;
551	}
552
553	self::$iframe_lazyload_flags = self::possible_lazyload_flags();
554	self::$iframe_lazyload_flags = array_merge( self::$iframe_lazyload_flags, apply_filters( 'optml_iframe_lazyload_flags', [ 'gform_ajax_frame', '<noscript', 'recaptcha', '-src' ] ) );
555
556	return self::$iframe_lazyload_flags;
557	}
558	/**
559	* Throw error on object clone
560	*
561	* The whole idea of the singleton design pattern is that there is a single
562	* object therefore, we don't want the object to be cloned.
563	*
564	* @codeCoverageIgnore
565	* @access public
566	* @return void
567	* @since 1.0.0
568	*/
569	public function __clone() {
570	// Cloning instances of the class is forbidden.
571	_doing_it_wrong( __FUNCTION__, esc_html__( 'Cheatin’ huh?', 'optimole-wp' ), '1.0.0' );
572	}
573
574	/**
575	* Disable unserializing of the class
576	*
577	* @codeCoverageIgnore
578	* @access public
579	* @return void
580	* @since 1.0.0
581	*/
582	public function __wakeup() {
583	// Unserializing instances of the class is forbidden.
584	_doing_it_wrong( __FUNCTION__, esc_html__( 'Cheatin’ huh?', 'optimole-wp' ), '1.0.0' );
585	}
586
587	}
588