Debouncing / On Finished Typing in jQuery

debouncing.js

// Returns a function, that, as long as it continues to be invoked, will not
// be triggered. The function will be called after it stops being called for
// N milliseconds. If `immediate` is passed, trigger the function on the
// leading edge, instead of the trailing.
function debounce(func, wait, immediate) {
    var timeout;
    return function () {
        var context = this, args = arguments;
        var later = function () {
            timeout = null;
            if (!immediate) {
                func.apply(context, args);
            }
        };

        var callNow = immediate && !timeout;
        clearTimeout(timeout);
        timeout = setTimeout(later, wait);

        if (callNow) {
            func.apply(context, args);
        }
    };
}

//example
//  only call displayProducts after typing
$('#product-filters [name=product_text_filter]').keyup(function () {
  debounce(displayProducts, 500)();
});