Imagify Image Optimization: Optimize Images | Compress & Convert to WebP/AVIF / 1.9.13

Imagify Image Optimization: Optimize Images | Compress & Convert to WebP/AVIF v1.9.13

imagify / assets / js / beat.js

beat.js in Imagify Image Optimization: Optimize Images | Compress & Convert to WebP/AVIF 1.9.13, at assets/js/beat.js

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1	/**
2	* Imagify beat API
3	*
4	* This is a modified version of WordPress’ Heartbeat (WP 5.2.1).
5	* The main difference is that it allows to prevent suspension entirely.
6	* It uses the var imagifybeatSettings on init.
7	*
8	* Custom jQuery events:
9	* - imagifybeat-send
10	* - imagifybeat-tick
11	* - imagifybeat-error
12	* - imagifybeat-connection-lost
13	* - imagifybeat-connection-restored
14	* - imagifybeat-nonces-expired
15	*
16	* @since 1.9.3
17	*/
18
19	window.imagify = window.imagify \|\| {};
20
21	/* eslint-disable no-use-before-define */
22	(function($, d, w, undefined) { // eslint-disable-line no-unused-vars, no-shadow, no-shadow-restricted-names
23
24	/**
25	* Constructs the Imagifybeat API.
26	*
27	* @since 1.9.3
28	* @constructor
29	*
30	* @return {Imagifybeat} An instance of the Imagifybeat class.
31	*/
32	var Imagifybeat = function() {
33	var $document = $( d ),
34	settings = {
35	// Suspend/resume.
36	suspend: false,
37
38	// Whether suspending is enabled.
39	suspendEnabled: true,
40
41	// Current screen id, defaults to the JS global 'pagenow' when present
42	// (in the admin) or 'front'.
43	screenId: '',
44
45	// XHR request URL, defaults to the JS global 'ajaxurl' when present.
46	url: '',
47
48	// Timestamp, start of the last connection request.
49	lastTick: 0,
50
51	// Container for the enqueued items.
52	queue: {},
53
54	// Connect interval (in seconds).
55	mainInterval: 60,
56
57	// Used when the interval is set to 5 sec. temporarily.
58	tempInterval: 0,
59
60	// Used when the interval is reset.
61	originalInterval: 0,
62
63	// Used to limit the number of AJAX requests.
64	minimalInterval: 0,
65
66	// Used together with tempInterval.
67	countdown: 0,
68
69	// Whether a connection is currently in progress.
70	connecting: false,
71
72	// Whether a connection error occurred.
73	connectionError: false,
74
75	// Used to track non-critical errors.
76	errorcount: 0,
77
78	// Whether at least one connection has been completed successfully.
79	hasConnected: false,
80
81	// Whether the current browser w is in focus and the user is active.
82	hasFocus: true,
83
84	// Timestamp, last time the user was active. Checked every 30 sec.
85	userActivity: 0,
86
87	// Flag whether events tracking user activity were set.
88	userActivityEvents: false,
89
90	// Timer that keeps track of how long a user has focus.
91	checkFocusTimer: 0,
92
93	// Timer that keeps track of how long needs to be waited before connecting to
94	// the server again.
95	beatTimer: 0
96	};
97
98	/**
99	* Sets local variables and events, then starts the beat.
100	*
101	* @since 1.9.3
102	* @access private
103	*
104	* @return {void}
105	*/
106	function initialize() {
107	var options, hidden, visibilityState, visibilitychange;
108
109	if ( typeof w.pagenow === 'string' ) {
110	settings.screenId = w.pagenow;
111	}
112
113	if ( typeof w.ajaxurl === 'string' ) {
114	settings.url = w.ajaxurl;
115	}
116
117	// Pull in options passed from PHP.
118	if ( typeof w.imagifybeatSettings === 'object' ) {
119	options = w.imagifybeatSettings;
120
121	// The XHR URL can be passed as option when w.ajaxurl is not set.
122	if ( ! settings.url && options.ajaxurl ) {
123	settings.url = options.ajaxurl;
124	}
125
126	/*
127	* The interval can be from 15 to 120 sec. and can be set temporarily to 5 sec.
128	* It can be set in the initial options or changed later through JS and/or
129	* through PHP.
130	*/
131	if ( options.interval ) {
132	settings.mainInterval = options.interval;
133
134	if ( settings.mainInterval < 15 ) {
135	settings.mainInterval = 15;
136	} else if ( settings.mainInterval > 120 ) {
137	settings.mainInterval = 120;
138	}
139	}
140
141	/*
142	* Used to limit the number of AJAX requests. Overrides all other intervals if
143	* they are shorter. Needed for some hosts that cannot handle frequent requests
144	* and the user may exceed the allocated server CPU time, etc. The minimal
145	* interval can be up to 600 sec. however setting it to longer than 120 sec.
146	* will limit or disable some of the functionality (like post locks). Once set
147	* at initialization, minimalInterval cannot be changed/overridden.
148	*/
149	if ( options.minimalInterval ) {
150	options.minimalInterval = parseInt( options.minimalInterval, 10 );
151	settings.minimalInterval = options.minimalInterval > 0 && options.minimalInterval <= 600 ? options.minimalInterval * 1000 : 0;
152	}
153
154	if ( settings.minimalInterval && settings.mainInterval < settings.minimalInterval ) {
155	settings.mainInterval = settings.minimalInterval;
156	}
157
158	// 'screenId' can be added from settings on the front end where the JS global
159	// 'pagenow' is not set.
160	if ( ! settings.screenId ) {
161	settings.screenId = options.screenId \|\| 'front';
162	}
163
164	if ( 'disable' === options.suspension ) {
165	disableSuspend();
166	}
167	}
168
169	// Convert to milliseconds.
170	settings.mainInterval = settings.mainInterval * 1000;
171	settings.originalInterval = settings.mainInterval;
172
173	/*
174	* Switch the interval to 120 seconds by using the Page Visibility API.
175	* If the browser doesn't support it (Safari < 7, Android < 4.4, IE < 10), the
176	* interval will be increased to 120 seconds after 5 minutes of mouse and keyboard
177	* inactivity.
178	*/
179	if ( typeof document.hidden !== 'undefined' ) {
180	hidden = 'hidden';
181	visibilitychange = 'visibilitychange';
182	visibilityState = 'visibilityState';
183	} else if ( typeof document.msHidden !== 'undefined' ) { // IE10
184	hidden = 'msHidden';
185	visibilitychange = 'msvisibilitychange';
186	visibilityState = 'msVisibilityState';
187	} else if ( typeof document.webkitHidden !== 'undefined' ) { // Android
188	hidden = 'webkitHidden';
189	visibilitychange = 'webkitvisibilitychange';
190	visibilityState = 'webkitVisibilityState';
191	}
192
193	if ( hidden ) {
194	if ( document[ hidden ] ) {
195	settings.hasFocus = false;
196	}
197
198	$document.on( visibilitychange + '.imagifybeat', function() {
199	if ( 'hidden' === document[ visibilityState ] ) {
200	blurred();
201	w.clearInterval( settings.checkFocusTimer );
202	} else {
203	focused();
204	if ( document.hasFocus ) {
205	settings.checkFocusTimer = w.setInterval( checkFocus, 10000 );
206	}
207	}
208	});
209	}
210
211	// Use document.hasFocus() if available.
212	if ( document.hasFocus ) {
213	settings.checkFocusTimer = w.setInterval( checkFocus, 10000 );
214	}
215
216	$( w ).on( 'unload.imagifybeat', function() {
217	// Don't connect anymore.
218	settings.suspend = true;
219
220	// Abort the last request if not completed.
221	if ( settings.xhr && 4 !== settings.xhr.readyState ) {
222	settings.xhr.abort();
223	}
224	} );
225
226	// Check for user activity every 30 seconds.
227	w.setInterval( checkUserActivity, 30000 );
228
229	// Start one tick after DOM ready.
230	$document.ready( function() {
231	settings.lastTick = time();
232	scheduleNextTick();
233	} );
234	}
235
236	/**
237	* Returns the current time according to the browser.
238	*
239	* @since 1.9.3
240	* @access private
241	*
242	* @return {int} Returns the current time.
243	*/
244	function time() {
245	return (new Date()).getTime();
246	}
247
248	/**
249	* Checks if the iframe is from the same origin.
250	*
251	* @since 1.9.3
252	* @access private
253	*
254	* @return {bool} Returns whether or not the iframe is from the same origin.
255	*/
256	function isLocalFrame( frame ) {
257	var origin, src = frame.src; // eslint-disable-line no-shadow
258
259	/*
260	* Need to compare strings as WebKit doesn't throw JS errors when iframes have different origin. It throws uncatchable exceptions.
261	*/
262	if ( src && /^https?:\/\//.test( src ) ) {
263	origin = w.location.origin ? w.location.origin : w.location.protocol + '//' + w.location.host;
264
265	if ( src.indexOf( origin ) !== 0 ) {
266	return false;
267	}
268	}
269
270	try {
271	if ( frame.contentWindow.document ) {
272	return true;
273	}
274	} catch ( e ) {} // eslint-disable-line no-empty
275
276	return false;
277	}
278
279	/**
280	* Checks if the document's focus has changed.
281	*
282	* @since 1.9.3
283	* @access private
284	*
285	* @return {void}
286	*/
287	function checkFocus() {
288	if ( settings.hasFocus && ! document.hasFocus() ) {
289	blurred();
290	} else if ( ! settings.hasFocus && document.hasFocus() ) {
291	focused();
292	}
293	}
294
295	/**
296	* Sets error state and fires an event on XHR errors or timeout.
297	*
298	* @since 1.9.3
299	* @access private
300	*
301	* @param {string} error The error type passed from the XHR.
302	* @param {int} httpStatus The HTTP status code passed from jqXHR (200, 404, 500, etc.).
303	* @return {void}
304	*/
305	function setErrorState( error, httpStatus ) {
306	var trigger;
307
308	if ( error ) {
309	switch ( error ) {
310	case 'abort':
311	// Do nothing.
312	break;
313	case 'timeout':
314	// No response for 30 sec.
315	trigger = true;
316	break;
317	case 'error':
318	if ( 503 === httpStatus && settings.hasConnected ) {
319	trigger = true;
320	break;
321	}
322	/* falls through */
323	case 'parsererror':
324	case 'empty':
325	case 'unknown':
326	settings.errorcount++;
327
328	if ( settings.errorcount > 2 && settings.hasConnected ) {
329	trigger = true;
330	}
331
332	break;
333	}
334
335	if ( trigger && ! hasConnectionError() ) {
336	settings.connectionError = true;
337	$document.trigger( 'imagifybeat-connection-lost', [ error, httpStatus ] );
338
339	if ( w.wp.hooks ) {
340	w.wp.hooks.doAction( 'imagifybeat.connection-lost', error, httpStatus );
341	}
342	}
343	}
344	}
345
346	/**
347	* Clears the error state and fires an event if there is a connection error.
348	*
349	* @since 1.9.3
350	* @access private
351	*
352	* @return {void}
353	*/
354	function clearErrorState() {
355	// Has connected successfully.
356	settings.hasConnected = true;
357
358	if ( hasConnectionError() ) {
359	settings.errorcount = 0;
360	settings.connectionError = false;
361	$document.trigger( 'imagifybeat-connection-restored' );
362
363	if ( w.wp.hooks ) {
364	w.wp.hooks.doAction( 'imagifybeat.connection-restored' );
365	}
366	}
367	}
368
369	/**
370	* Gathers the data and connects to the server.
371	*
372	* @since 1.9.3
373	* @access private
374	*
375	* @return {void}
376	*/
377	function connect() {
378	var ajaxData, imagifybeatData;
379
380	// If the connection to the server is slower than the interval,
381	// imagifybeat connects as soon as the previous connection's response is received.
382	if ( settings.connecting \|\| settings.suspend ) {
383	return;
384	}
385
386	settings.lastTick = time();
387
388	imagifybeatData = $.extend( {}, settings.queue );
389	// Clear the data queue. Anything added after this point will be sent on the next tick.
390	settings.queue = {};
391
392	$document.trigger( 'imagifybeat-send', [ imagifybeatData ] );
393
394	if ( w.wp.hooks ) {
395	w.wp.hooks.doAction( 'imagifybeat.send', imagifybeatData );
396	}
397
398	ajaxData = {
399	data: imagifybeatData,
400	interval: settings.tempInterval ? settings.tempInterval / 1000 : settings.mainInterval / 1000,
401	_nonce: typeof w.imagifybeatSettings === 'object' ? w.imagifybeatSettings.nonce : '',
402	action: 'imagifybeat',
403	screen_id: settings.screenId,
404	has_focus: settings.hasFocus
405	};
406
407	if ( 'customize' === settings.screenId ) {
408	ajaxData.wp_customize = 'on';
409	}
410
411	settings.connecting = true;
412	settings.xhr = $.ajax( {
413	url: settings.url,
414	type: 'post',
415	timeout: 60000, // Throw an error if not completed after 60 sec.
416	data: ajaxData,
417	dataType: 'json'
418	} ).always( function() {
419	settings.connecting = false;
420	scheduleNextTick();
421	} ).done( function( response, textStatus, jqXHR ) {
422	var newInterval;
423
424	if ( ! response ) {
425	setErrorState( 'empty' );
426	return;
427	}
428
429	clearErrorState();
430
431	if ( response.nonces_expired ) {
432	$document.trigger( 'imagifybeat-nonces-expired' );
433
434	if ( w.wp.hooks ) {
435	w.wp.hooks.doAction( 'imagifybeat.nonces-expired' );
436	}
437	}
438
439	// Change the interval from PHP
440	if ( response.imagifybeat_interval ) {
441	newInterval = response.imagifybeat_interval;
442	delete response.imagifybeat_interval;
443	}
444
445	// Update the imagifybeat nonce if set.
446	if ( response.imagifybeat_nonce && typeof w.imagifybeatSettings === 'object' ) {
447	w.imagifybeatSettings.nonce = response.imagifybeat_nonce;
448	delete response.imagifybeat_nonce;
449	}
450
451	$document.trigger( 'imagifybeat-tick', [ response, textStatus, jqXHR ] );
452
453	if ( w.wp.hooks ) {
454	w.wp.hooks.doAction( 'imagifybeat.tick', response, textStatus, jqXHR );
455	}
456
457	// Do this last. Can trigger the next XHR if connection time > 5 sec. and newInterval == 'fast'.
458	if ( newInterval ) {
459	interval( newInterval );
460	}
461	} ).fail( function( jqXHR, textStatus, error ) {
462	setErrorState( textStatus \|\| 'unknown', jqXHR.status );
463	$document.trigger( 'imagifybeat-error', [ jqXHR, textStatus, error ] );
464
465	if ( w.wp.hooks ) {
466	w.wp.hooks.doAction( 'imagifybeat.error', jqXHR, textStatus, error );
467	}
468	} );
469	}
470
471	/**
472	* Schedules the next connection.
473	*
474	* Fires immediately if the connection time is longer than the interval.
475	*
476	* @since 1.9.3
477	* @access private
478	*
479	* @return {void}
480	*/
481	function scheduleNextTick() {
482	var delta = time() - settings.lastTick,
483	interv = settings.mainInterval;
484
485	if ( settings.suspend ) {
486	return;
487	}
488
489	if ( ! settings.hasFocus && settings.suspendEnabled ) {
490	// When no user activity or the window lost focus, increase polling interval to 120 seconds, but only if suspend is enabled.
491	interv = 120000; // 120 sec.
492	} else if ( settings.countdown > 0 && settings.tempInterval ) {
493	interv = settings.tempInterval;
494	settings.countdown--;
495
496	if ( settings.countdown < 1 ) {
497	settings.tempInterval = 0;
498	}
499	}
500
501	if ( settings.minimalInterval && interv < settings.minimalInterval ) {
502	interv = settings.minimalInterval;
503	}
504
505	w.clearTimeout( settings.beatTimer );
506
507	if ( delta < interv ) {
508	settings.beatTimer = w.setTimeout(
509	function() {
510	connect();
511	},
512	interv - delta
513	);
514	} else {
515	connect();
516	}
517	}
518
519	/**
520	* Sets the internal state when the browser w becomes hidden or loses focus.
521	*
522	* @since 1.9.3
523	* @access private
524	*
525	* @return {void}
526	*/
527	function blurred() {
528	settings.hasFocus = false;
529	}
530
531	/**
532	* Sets the internal state when the browser w becomes visible or is in focus.
533	*
534	* @since 1.9.3
535	* @access private
536	*
537	* @return {void}
538	*/
539	function focused() {
540	settings.userActivity = time();
541
542	// Resume if suspended
543	settings.suspend = false;
544
545	if ( ! settings.hasFocus ) {
546	settings.hasFocus = true;
547	scheduleNextTick();
548	}
549	}
550
551	/**
552	* Runs when the user becomes active after a period of inactivity.
553	*
554	* @since 1.9.3
555	* @access private
556	*
557	* @return {void}
558	*/
559	function userIsActive() {
560	settings.userActivityEvents = false;
561	$document.off( '.imagifybeat-active' );
562
563	$( 'iframe' ).each( function( i, frame ) {
564	if ( isLocalFrame( frame ) ) {
565	$( frame.contentWindow ).off( '.imagifybeat-active' );
566	}
567	} );
568
569	focused();
570	}
571
572	/**
573	* Checks for user activity.
574	*
575	* Runs every 30 sec. Sets 'hasFocus = true' if user is active and the w is
576	* in the background. Sets 'hasFocus = false' if the user has been inactive
577	* (no mouse or keyboard activity) for 5 min. even when the w has focus.
578	*
579	* @since 1.9.3
580	* @access private
581	*
582	* @return {void}
583	*/
584	function checkUserActivity() {
585	var lastActive = settings.userActivity ? time() - settings.userActivity : 0;
586
587	// Set hasFocus to false when no mouse or keyboard activity for 5 min.
588	if ( lastActive > 300000 && settings.hasFocus ) {
589	blurred();
590	}
591
592	// Suspend after 10 min. of inactivity.
593	if ( settings.suspendEnabled && lastActive > 600000 ) {
594	settings.suspend = true;
595	}
596
597	if ( ! settings.userActivityEvents ) {
598	$document.on( 'mouseover.imagifybeat-active keyup.imagifybeat-active touchend.imagifybeat-active', function() {
599	userIsActive();
600	} );
601
602	$( 'iframe' ).each( function( i, frame ) {
603	if ( isLocalFrame( frame ) ) {
604	$( frame.contentWindow ).on( 'mouseover.imagifybeat-active keyup.imagifybeat-active touchend.imagifybeat-active', function() {
605	userIsActive();
606	} );
607	}
608	} );
609
610	settings.userActivityEvents = true;
611	}
612	}
613
614	// Public methods.
615
616	/**
617	* Checks whether the w (or any local iframe in it) has focus, or the user
618	* is active.
619	*
620	* @since 1.9.3
621	* @memberOf imagify.beat.prototype
622	*
623	* @return {bool} True if the w or the user is active.
624	*/
625	function hasFocus() {
626	return settings.hasFocus;
627	}
628
629	/**
630	* Checks whether there is a connection error.
631	*
632	* @since 1.9.3
633	* @memberOf imagify.beat.prototype
634	*
635	* @return {bool} True if a connection error was found.
636	*/
637	function hasConnectionError() {
638	return settings.connectionError;
639	}
640
641	/**
642	* Connects as soon as possible regardless of 'hasFocus' state.
643	*
644	* Will not open two concurrent connections. If a connection is in progress,
645	* will connect again immediately after the current connection completes.
646	*
647	* @since 1.9.3
648	* @memberOf imagify.beat.prototype
649	*
650	* @return {void}
651	*/
652	function connectNow() {
653	settings.lastTick = 0;
654	scheduleNextTick();
655	}
656
657	/**
658	* Disables suspending.
659	*
660	* Should be used only when Imagifybeat is performing critical tasks like
661	* autosave, post-locking, etc. Using this on many screens may overload the
662	* user's hosting account if several browser ws/tabs are left open for a
663	* long time.
664	*
665	* @since 1.9.3
666	* @memberOf imagify.beat.prototype
667	*
668	* @return {void}
669	*/
670	function disableSuspend() {
671	settings.suspendEnabled = false;
672	}
673
674	/**
675	* Enables suspending.
676	*
677	* @since 1.9.3
678	* @memberOf imagify.beat.prototype
679	*
680	* @return {void}
681	*/
682	function enableSuspend() {
683	settings.suspendEnabled = true;
684	}
685
686	/**
687	* Gets/Sets the interval.
688	*
689	* When setting to 'fast' or 5, the interval is 5 seconds for the next 30 ticks
690	* (for 2 minutes and 30 seconds) by default. In this case the number of 'ticks'
691	* can be passed as second argument. If the window doesn't have focus, the
692	* interval slows down to 2 min.
693	*
694	* @since 1.9.3
695	* @memberOf imagify.beat.prototype
696	*
697	* @param {string\|int} speed Interval: 'fast' or 5, 15, 30, 60, 120. Fast equals 5.
698	* @param {string} ticks Tells how many ticks before the interval reverts back. Used with speed = 'fast' or 5.
699	* @return {int} Current interval in seconds.
700	*/
701	function interval( speed, ticks ) {
702	var newInterval,
703	oldInterval = settings.tempInterval ? settings.tempInterval : settings.mainInterval;
704
705	if ( speed ) {
706	switch ( speed ) {
707	case 'fast':
708	case 5:
709	newInterval = 5000;
710	break;
711	case 15:
712	newInterval = 15000;
713	break;
714	case 30:
715	newInterval = 30000;
716	break;
717	case 60:
718	newInterval = 60000;
719	break;
720	case 120:
721	newInterval = 120000;
722	break;
723	case 'long-polling':
724	// Allow long polling, (experimental)
725	settings.mainInterval = 0;
726	return 0;
727	default:
728	newInterval = settings.originalInterval;
729	}
730
731	if ( settings.minimalInterval && newInterval < settings.minimalInterval ) {
732	newInterval = settings.minimalInterval;
733	}
734
735	if ( 5000 === newInterval ) {
736	ticks = parseInt( ticks, 10 ) \|\| 30;
737	ticks = ticks < 1 \|\| ticks > 30 ? 30 : ticks;
738
739	settings.countdown = ticks;
740	settings.tempInterval = newInterval;
741	} else {
742	settings.countdown = 0;
743	settings.tempInterval = 0;
744	settings.mainInterval = newInterval;
745	}
746
747	// Change the next connection time if new interval has been set.
748	// Will connect immediately if the time since the last connection
749	// is greater than the new interval.
750	if ( newInterval !== oldInterval ) {
751	scheduleNextTick();
752	}
753	}
754
755	return settings.tempInterval ? settings.tempInterval / 1000 : settings.mainInterval / 1000;
756	}
757
758	/**
759	* Resets the interval.
760	*
761	* @since 1.9.3
762	* @memberOf imagify.beat.prototype
763	*
764	* @return {int} Current interval in seconds.
765	*/
766	function resetInterval() {
767	return interval( settings.originalInterval );
768	}
769
770	/**
771	* Enqueues data to send with the next XHR.
772	*
773	* As the data is send asynchronously, this function doesn't return the XHR
774	* response. To see the response, use the custom jQuery event 'imagifybeat-tick'
775	* on the document, example:
776	* $(document).on( 'imagifybeat-tick.myname', function( event, data, textStatus, jqXHR ) {
777	* // code
778	* });
779	* If the same 'handle' is used more than once, the data is not overwritten when
780	* the third argument is 'true'. Use `imagify.beat.isQueued('handle')` to see if
781	* any data is already queued for that handle.
782	*
783	* @since 1.9.3
784	* @memberOf imagify.beat.prototype
785	*
786	* @param {string} handle Unique handle for the data, used in PHP to receive the data.
787	* @param {mixed} data The data to send.
788	* @param {bool} noOverwrite Whether to overwrite existing data in the queue.
789	* @return {bool} True if the data was queued.
790	*/
791	function enqueue( handle, data, noOverwrite ) {
792	if ( handle ) {
793	if ( noOverwrite && this.isQueued( handle ) ) {
794	return false;
795	}
796
797	settings.queue[handle] = data;
798	return true;
799	}
800	return false;
801	}
802
803	/**
804	* Checks if data with a particular handle is queued.
805	*
806	* @since 1.9.3
807	*
808	* @param {string} handle The handle for the data.
809	* @return {bool} True if the data is queued with this handle.
810	*/
811	function isQueued( handle ) {
812	if ( handle ) {
813	return settings.queue.hasOwnProperty( handle );
814	}
815	}
816
817	/**
818	* Removes data with a particular handle from the queue.
819	*
820	* @since 1.9.3
821	* @memberOf imagify.beat.prototype
822	*
823	* @param {string} handle The handle for the data.
824	*/
825	function dequeue( handle ) {
826	if ( handle ) {
827	delete settings.queue[handle];
828	}
829	}
830
831	/**
832	* Gets data that was enqueued with a particular handle.
833	*
834	* @since 1.9.3
835	* @memberOf imagify.beat.prototype
836	*
837	* @param {string} handle The handle for the data.
838	* @return {mixed} The data or undefined.
839	*/
840	function getQueuedItem( handle ) {
841	if ( handle ) {
842	return this.isQueued( handle ) ? settings.queue[ handle ] : undefined;
843	}
844	}
845
846	initialize();
847
848	// Expose public methods.
849	return {
850	hasFocus: hasFocus,
851	connectNow: connectNow,
852	disableSuspend: disableSuspend,
853	enableSuspend: enableSuspend,
854	interval: interval,
855	resetInterval: resetInterval,
856	hasConnectionError: hasConnectionError,
857	enqueue: enqueue,
858	dequeue: dequeue,
859	isQueued: isQueued,
860	getQueuedItem: getQueuedItem
861	};
862	};
863
864	/**
865	* Contains the Imagifybeat API.
866	*
867	* @namespace imagify.beat
868	* @type {Imagifybeat}
869	*/
870	w.imagify.beat = new Imagifybeat();
871
872	} )( jQuery, document, window );
873