que-etc/intersection-observer-polyfill

A polyfill of IntersectionObserver API

intersection-observer-polyfill's Issues

It doesn't work for Safari

I'm on version 12, Mac OS 10.14 Mojave

typescript?

any plan to add type definitions for typescript?

Uncaught SyntaxError: Unexpected token import

Hello, would you compile the source?

Performance Benchmarks

Implementation looks very interesting, especially the use of MutationObserver. I was wondering how performant is the polyfill when MutationObserver is used, or dirty polling is used.

The existing best practice for lazy loading of images includes attaching a single debounced window scroll listener and using getBoundingClientRect check if images are in viewport, but is far from a full proof solution.

One may assume that since IntersectionObserver's are cheap, they could be added to observe each image (and disconnected after images are loaded / load failed). In this case, a person using this polyfill (or any other for that matter) would unknowingly attach a multiple scroll listeners which would harm performance rather than improve it.

It would be interesting to see the performance impact in such a case.