Lazy load images blogger

Lazy load images blogger
Lazy load images blogger

    lazy loading blogger berguna untuk :
  1. Mempercepat laman web
  2. Meningkatkan rating pagespeed
HTML (Usage)

<img alt='' data-src='https://lh3.googleusercontent.com/proxy/FCTXDOBcEj5ojJZCa5wsRX4hG0C1qod8MXxYlCcvUGT7EGMROVrUqXFf0LAuxtvvRaFKPr3mn-yUl3dMZj_ygE--d2lPheO6CSUofHexbWd1LQ6NV4NbJCReDlMs=w72-h58-p-k-no-nu' src='data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAMAAAAoyzS7AAAAA1BMVEXz8/SVuXQoAAAACklEQVQI12NgAAAAAgAB4iG8MwAAAABJRU5ErkJggg=='/>
  • src='data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAMAAAAoyzS7AAAAA1BMVEXz8/SVuXQoAAAACklEQVQI12NgAAAAAgAB4iG8MwAAAABJRU5ErkJggg==' : source gambar dengan resolusi paling rendah
  • data-src='https://lh3.googleusercontent.com/proxy/FCTXDOBcEj5ojJZCa5wsRX4hG0C1qod8MXxYlCcvUGT7EGMROVrUqXFf0LAuxtvvRaFKPr3mn-yUl3dMZj_ygE--d2lPheO6CSUofHexbWd1LQ6NV4NbJCReDlMs=w72-h58-p-k-no-nu' : source gambar asli
JS (taruh diatas </body>)

<script>
//<![CDATA[
const config = {
rootMargin: '0px 0px 50px 0px',
threshold: 0
};
const imgs = document.querySelectorAll('[data-src]');

if (typeof intersectionObserver != 'undefined') {
// register the config object with an instance
// of intersectionObserver
let observer = new intersectionObserver(function (entries, self) {
// iterate over each entry
entries.forEach(entry => {
// process just the images that are intersecting.
// isIntersecting is a property exposed by the interface
if (entry.isIntersecting) {
// custom function that copies the path to the img
// from data-src to src
preloadImage(entry.target);
// the image is now in place, stop watching
self.unobserve(entry.target);
}
});
}, config);

imgs.forEach(img => {
observer.observe(img);
});
} else {
imgs.forEach(img => {
preloadImage(img)
});
}

function preloadImage(e) {
var a = e.getAttribute('src'), b = e.getAttribute('data-src');
if (b.trim() != ''){
e.src = b.trim();
}
}
]]>
</script>
FULL DEMO

See the Pen Pure javascript lazy load images by dimas lanjaka (@dimaslanjaka) on CodePen.