Lozad.js
▻https://github.com/ApoorvSaxena/lozad.js
Highly performant, light ~0.5kb and configurable #lazy_loader in pure JS with no dependencies for #images, #iframes and more, using #IntersectionObserver API
Existing lazy loading libraries hook up to the scroll event or use a periodic timer and call getBoundingClientRect() on elements that need to be lazy loaded. This approach, however, is painfully slow as each call to getBoundingClientRect() forces the browser to re-layout the entire page and will introduce considerable jank to your website.
Making this more efficient and performant is what IntersectionObserver is designed for, and it’s landed in Chrome 51. IntersectionObservers let you know when an observed element enters or exits the browser’s viewport.
En lien avec ▻https://seenthis.net/messages/619904
