mediawiki-skins-Citizen/resources/scripts/lazyload.js
2019-08-15 14:05:50 -04:00

29 lines
1,004 B
JavaScript

/*
* Citizen - Lazyload JS
* https://starcitizen.tools
*
* Lazyloading images with Native API or IntersectionObserver
*/
// TODO: Implement Native API
// IntersectionObserver API
if( typeof IntersectionObserver !== "undefined" && "forEach" in NodeList.prototype ) {
var observer = new IntersectionObserver(function(changes) {
if ("connection" in navigator && navigator.connection.saveData === true) {
return;
}
changes.forEach(function(change) {
if(change.isIntersecting) {
change.target.setAttribute("src", change.target.getAttribute("data-src"));
if(change.target.hasAttribute("data-srcset")) {
change.target.setAttribute("srcset", change.target.getAttribute("data-srcset"));
}
observer.unobserve(change.target);
}
});
});
document.querySelectorAll("img[data-src]").forEach(function(img) {
observer.observe(img);
});
}