$('.menu-item-quantity input').change( function() {
  updateQuantity(this);
});

function updateQuantity(quantityInput){

    var productRow = $(quantityInput).parent().parent();
    var price = parseFloat(productRow.children('.menu-item-price').text());
    var quantity = $(quantityInput).val();
    var linePrice = price * quantity;

    productRow.children('.item-total').each(function () {
      $(this).fadeOut(fadeTime, function() {
        $(this).text(linePrice.toFixed(2));
        recalculateCart();
        $(this).fadeIn(fadeTime);
      });
    });
  }

function renderCart(){

  var $shoppingCart = $(".shopping-cart");
  $shoppingCart.html("");
  var visibleAttributes = [ "name", "price" ];
  $.each(cart, function(i, item){
    var cartItemHTML = "<div class='cart-item'>";
    $.each(visibleAttributes, function(i, attribute){
      cartItemHTML += "<div class=menu-item-"  + attribute + ">" + item[attribute] + "</div>";
      });
    cartItemHTML += "<div class='menu-item-quantity input'>" + "<input type='number' value='1' min='1'>" + "</div>";
    cartItemHTML += "<div class='item-total'>" + item.price + "</div>";
    cartItemHTML += "<div class='product-removal'>" + "<button class='remove-menu-item'>" + "X" + "</button>" + "</div>";
    cartItemHTML += "</div>";
    $shoppingCart.append(cartItemHTML);
    recalculateCart()
  });
}