// ctor
var loader = new Loader();

// chainable `add` to enqueue a resource
loader.add(url, options);

// chainable `before` to add a middleware that runs for each resource, *before* loading a resource.
// this is useful to implement custom caching modules (using filesystem, indexeddb, memory, etc).
loader.before(cachingMiddleware);

// chainable `after` to add a middleware that runs for each resource, *after* loading a resource.
// this is useful to implement custom parsing modules (like spritesheet parsers, spine parser, etc).
loader.after(parsingMiddleware);


// `load` method loads the queue of resources, and calls the passed in callback called once all
// resources have loaded.
loader.load(function (resources) {
    // resources is an array of resource objects that have a couple properties:
    // - `url`: The URL that the resource was loaded from
    // - `error`: The error that happened when trying to load (if any)
    // - `data`: The raw data that was loaded
    // also may contain other properties based on the middleware that runs.
});

// throughout the process multiple events can happen.
loader.on('progress', ...); // called once per loaded/errored file
loader.on('error', ...); // called once per errored file
loader.on('load', ...); // called once per loaded file
loader.on('complete', ...); // called once when the queued resources all load.

npm i && npm run build