AJAX Loading Indicator

ajax.js

/* global baseUrl, alert, setTimeout */
define(
    ['jquery'],
    function ($) {
        var loadingCount = 0,
            loadingMarkup = '<div id="loading-indicator" style="display:none;"><div></div><img src="/Content/Images/loading.gif" /></div>',
            hiding = false,
            showLoading = function () {
                loadingCount++;
                if (loadingCount !== 1) { return; }

                if (hiding) { hiding = false; }

                setTimeout(function () {
                    if (hiding) { return; }

                    $(loadingMarkup)
                        .appendTo('body')
                        .fadeIn('fast');
                }, 100);
            },
            hideLoading = function () {
                loadingCount--;
                if (loadingCount !== 0) { return; }

                hiding = true;

                setTimeout(function () {
                    if (!hiding) { return; }

                    var indicator = $('body').find('#loading-indicator');
                    if (indicator.length === 0) { return; }

                    indicator
                        .fadeOut('slow')
                        .queue(function () {
                            indicator.remove();
                        });
                }, 100);
            };

        $.ajaxPrefilter(function (options, originalOptions, jqXHR) {
            showLoading();
            jqXHR.always(hideLoading);
        });
    });