var productViewer = function(element) { this.element = element; this.handleContainer = this.element.find('.cd-product-viewer-handle'); this.handleFill = this.handleContainer.children('.fill'); //... this.frames = this.element.data('frame'); //increase this value to increase the friction while dragging on the image - it has to be bigger than zero this.friction = this.element.data('friction'); this.visibleFrame = 0; this.loaded = false; //... this.loadFrames(); } productViewer.prototype.loadFrames = function() { var self = this, imageUrl = this.slideShow.data('image'); //you need this to check if the image sprite has been loaded $('').attr('src', imageUrl).load(function() { self.loaded = true; }); this.loading('0.5'); //triggers loading animation } var productToursWrapper = $('.cd-product-viewer-wrapper'); productToursWrapper.each(function(){ new productViewer($(this)); });