Optimole – Optimize Images | Convert WebP & AVIF | CDN & Lazy Load | Image Optimization / 4.2.5

Optimole – Optimize Images | Convert WebP & AVIF | CDN & Lazy Load | Image Optimization v4.2.5

optimole-wp / assets / js / modules / background.js

background.js in Optimole – Optimize Images | Convert WebP & AVIF | CDN & Lazy Load | Image Optimization 4.2.5, at assets/js/modules/background.js

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1	/**
2	* Optimole Background Image Handler Module
3	* Handles background image detection and lazy loading observation
4	*/
5
6	import { optmlLogger } from './logger.js';
7	import { optmlDomUtils } from './dom-utils.js';
8
9	/**
10	* Background image handling utilities
11	*/
12	export const optmlBackground = {
13	/**
14	* Setup background image observation for lazy loading
15	* @param {Array} elements - DOM elements to observe
16	* @param {string} selector - CSS selector for the elements
17	* @param {Map} selectorMap - Map to track above-fold selectors
18	* @param {IntersectionObserver} observer - Intersection observer instance
19	* @returns {number} Number of elements waiting for lazy load
20	*/
21	setupBackgroundImageObservation: function(elements, selector, selectorMap, observer) {
22	// Create a single shared observer for all elements
23	const classObserver = new MutationObserver((mutations) => {
24	for (const mutation of mutations) {
25	if (mutation.type === 'attributes' && mutation.attributeName === 'class') {
26	const element = mutation.target;
27
28	// Check if element now has the required class and a background image
29	if (element.classList.contains('optml-bg-lazyloaded') &&
30	optmlDomUtils.hasBackgroundImage(element)) {
31	// Start observing for visibility
32	observer.observe(element);
33
34	// Stop watching for class changes on this element
35	classObserver.disconnect(element);
36
37	const specificSelector = element.getAttribute('data-optml-specific-selector');
38	optmlLogger.info(`Background element "${specificSelector}" is now observable`);
39	}
40	}
41	}
42	});
43
44	// Process all elements at once
45	const elementsToWatch = [];
46
47	elements.forEach(element => {
48	// Generate a specific selector for this element
49	const specificSelector = optmlDomUtils.getUniqueSelector(element);
50
51	// Mark the element with its selectors for identification in the observer
52	element.setAttribute('data-optml-bg-selector', selector);
53	element.setAttribute('data-optml-specific-selector', specificSelector);
54
55	// If already lazyloaded with background image, observe immediately
56	if (element.classList.contains('optml-bg-lazyloaded') &&
57	optmlDomUtils.hasBackgroundImage(element)) {
58	observer.observe(element);
59	} else {
60	// Otherwise, add to the list to watch for class changes
61	elementsToWatch.push(element);
62	}
63	});
64
65	// Set up observation for class changes only on elements that need it
66	if (elementsToWatch.length > 0) {
67	elementsToWatch.forEach(element => {
68	classObserver.observe(element, { attributes: true, attributeFilter: ['class'] });
69	});
70
71	// Set a timeout to disconnect the observer after a reasonable time
72	setTimeout(() => {
73	classObserver.disconnect();
74	optmlLogger.info(`Stopped waiting for lazyload on ${selector} elements`);
75	}, 5000);
76	}
77
78	return elementsToWatch.length;
79	},
80
81	/**
82	* Extract background image URLs for elements with specific selectors
83	* @param {Array} bgSelectors - Array of CSS selectors
84	* @returns {Map} Map of selector -> Map of (specific selector -> URLs)
85	*/
86	extractBackgroundImageUrls: function(bgSelectors) {
87	const bgImageUrls = new Map();
88
89	if (!bgSelectors \|\| !Array.isArray(bgSelectors)) {
90	return bgImageUrls;
91	}
92
93	bgSelectors.forEach(selector => {
94	const selectorUrlMap = new Map();
95	bgImageUrls.set(selector, selectorUrlMap);
96
97	try {
98	document.querySelectorAll(selector).forEach(element => {
99	if (element.classList.contains('optml-bg-lazyloaded')) {
100	const bgImage = optmlDomUtils.hasBackgroundImage(element, true);
101
102	if (bgImage === false) return;
103
104	// Get the specific selector for this element
105	const specificSelector = optmlDomUtils.getUniqueSelector(element);
106
107	if (!specificSelector) return;
108
109	// Extract all URLs from the background-image property
110	const urls = optmlDomUtils.extractUrlsFromBgImage(bgImage);
111
112	if (urls && urls.length > 0) {
113	selectorUrlMap.set(specificSelector, urls);
114	optmlLogger.info(`Found background image URL(s) for "${specificSelector}":`, urls);
115	}
116	}
117	});
118	} catch (e) {
119	optmlLogger.error('Error extracting background URLs for selector:', selector, e);
120	}
121	});
122
123	return bgImageUrls;
124	},
125
126	/**
127	* Process background selectors and setup observation
128	* @param {Array} bgSelectors - Array of CSS selectors
129	* @param {IntersectionObserver} observer - Intersection observer instance
130	* @returns {Object} Object containing selectorMap and pendingElements count
131	*/
132	processBackgroundSelectors: function(bgSelectors, observer) {
133	const selectorMap = new Map();
134	let pendingElements = 0;
135
136	if (!bgSelectors \|\| !Array.isArray(bgSelectors) \|\| bgSelectors.length === 0) {
137	return { selectorMap, pendingElements };
138	}
139
140	optmlLogger.info('Processing background selectors:', bgSelectors);
141
142	bgSelectors.forEach(selector => {
143	try {
144	const elements = document.querySelectorAll(selector);
145	if (elements.length === 0) {
146	optmlLogger.warn('No elements found for background selector:', selector);
147	return;
148	}
149
150	// Initialize this selector with an empty array for above-fold elements
151	selectorMap.set(selector, []);
152
153	// Setup observation for these elements
154	pendingElements += this.setupBackgroundImageObservation(
155	Array.from(elements),
156	selector,
157	selectorMap,
158	observer
159	);
160
161	optmlLogger.info(`Processed ${elements.length} elements for background selector: ${selector}`);
162	} catch (e) {
163	optmlLogger.error('Error processing background selector:', selector, e);
164	}
165	});
166
167	return { selectorMap, pendingElements };
168	}
169	};
170