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(function () { |
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'use strict'; |
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|
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// Embed Block — lazy-load iframes on scroll for performance |
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function initEmbeds() { |
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var iframes = document.querySelectorAll('.bkbg-embed-iframe[loading="lazy"]'); |
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if (!iframes.length) return; |
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|
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// Modern browsers handle loading="lazy" natively on iframes |
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// This is a fallback for older browsers |
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if ('loading' in HTMLIFrameElement.prototype) return; |
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|
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if (!('IntersectionObserver' in window)) return; |
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|
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var obs = new IntersectionObserver(function (entries) { |
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entries.forEach(function (entry) { |
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if (!entry.isIntersecting) return; |
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var iframe = entry.target; |
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var dataSrc = iframe.getAttribute('data-src'); |
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if (dataSrc) { |
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iframe.src = dataSrc; |
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iframe.removeAttribute('data-src'); |
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} |
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obs.unobserve(iframe); |
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}); |
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}, { rootMargin: '200px 0px' }); |
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|
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iframes.forEach(function (iframe) { |
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if (iframe.src && !iframe.getAttribute('data-src')) { |
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iframe.setAttribute('data-src', iframe.src); |
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iframe.removeAttribute('src'); |
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} |
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obs.observe(iframe); |
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}); |
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} |
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|
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if (document.readyState === 'loading') { |
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document.addEventListener('DOMContentLoaded', initEmbeds); |
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} else { |
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initEmbeds(); |
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} |
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}()); |
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