jellyfin-web/src/components/images/imageFetcher.js

define(['dom'], function (dom) {
    'use strict';

    function loadImage(elem, url) {

        if (!elem) {
            return Promise.reject('elem cannot be null');
        }

        if (elem.tagName !== 'IMG') {

            elem.style.backgroundImage = "url('" + url + "')";
            return Promise.resolve();

            //return loadImageIntoImg(document.createElement('img'), url).then(function () {
            //    elem.style.backgroundImage = "url('" + url + "')";
            //    return Promise.resolve();
            //});

        }
        return loadImageIntoImg(elem, url);
    }

    function loadImageIntoImg(elem, url) {
        return new Promise(function (resolve, reject) {

            dom.addEventListener(elem, 'load', resolve, {
                once: true
            });
            elem.setAttribute('src', url);
        });
    }

    return {
        loadImage: loadImage
    };

});