Load Multiple Images with callbacks

gistfile1.js

/**
 * [loadAssets description]
 * @param  {[type]} assets [description]
 * @return {[type]}        [description]
 */

function loadAssets(assets, fn, onFinish) {
    var promises = [];

    for (var i = 0; i < assets.length; i++) {
        var promise = imagePromise(assets[i], assets.length, fn);
        promises.push(promise);
    }

    $.when.apply($, promises).done(function () {
        Registry.cachedImages = {};
        for (var i = 0; i < arguments.length; i++) {
            
            // from "assets/blah/myImage.jpg to myImage
            var splitName = String( $(arguments[i]).attr('src') ).split("/");
            splitName = String( splitName[splitName.length - 1] ).split(".");
            splitName = splitName[0];
            
            Registry.cachedImages[splitName] = arguments[i];
        }

        onFinish();

    });

}

// Create a Promise for loading an image!
// Basically taking out the useful, tricky, and heavily refined bit from
// http://desandro.github.io/imagesloaded/
function imagePromise(src, length, fn) {
    var deferred = $.Deferred();
    var img = new Image();
    var pool = length - 1;
    var currentCount = 0;
    var func = fn;

    function resolve() {
        // Resolution callbacks receive the image, which you can then inject into the DOM
        // to avoid triggering an extra HTTP request in IE

        func();
        return deferred.resolve(img);
    }

    // Resolution events
    $(img).on({
        error: deferred.reject,
        load: resolve
    });

    // Attach the source afterwards, since DOM synchronicity is weird:
    // A cached image will sometimes load or error on assignment
    img.src = src;

    // ...But sometimes cached images never fire load!
    // In this case they would already be in the DOM at this point. We need to infer it:
    if (img.complete && img.naturalWidth !== undefined) {
        // And then use setTimeout to resolve asynchronously (otherwise promise is broken!)
        setTimeout(resolve);
    }

    return deferred.promise();
}