const QuickPost = function(w) { this.window = w; } QuickPost.prototype.init = function() { var doc = this.window.document; var images = doc.querySelectorAll('.quick-image img'); for (var i = 0, len = images.length; i < len; i++) { (function(image) { var source = image.getAttribute('data-src'); var loader = new Image(); loader.onload = function() { image.style.backgroundImage = 'url(' + source + ')'; image.style.backgroundSize = 'cover'; } loader.src = source; })(images[i]); } } module.exports = QuickPost