Jumpseller's Javascript method: productVariantListener to display Product stock info

productVariantListener_product_stock.js

<script type="text/javascript">
  // more info at: https://jumpseller.com/support/javascript-library
  var callbackFunction = function(event, productInfo){
    if(!$.isEmptyObject(productInfo)){
      console.log(productInfo);
      alert('stock: ' + productInfo.stock + ', stock unlimited?:' + productInfo.stock_unlimited);
    }
  };

  //update Product information with current variant
  Jumpseller.productVariantListener('select.prod-options', {product: '{{ product | json }}', callback: callbackFunction});
</script>