onWindowScroll() {

        var scrollPos = $(window).scrollTop();
        var triggerPos =  $(document).height() - $(window).height() * 1.2;

        if (scrollPos > triggerPos) {
            this.collection.getNextPage(this.fetchParams);
        }
    }
 onLoadMoreButtonClick(event) {
     event.preventDefault();
     this.collection.getNextPage(this.fetchParams);
 }