Ajax Module Loader

Analyzes page contents to determine what new javascript modules need
to be loaded and which old modules need to be unloaded.

Javascript Native API's used:

(polyfill as needed)

- CustomEvent()
- fetch()
- Promise()
- Symbol()

Lifecycle

$3

This is where you will want to attach any global event listeners to the window or
document. It is only called when the user navigates from a page that does not contain
this script to one that does.

$3

This is where you will want to interact with the DOM. This method is called immediately
after onInit with a context of the document. If the user navigates from a page
that contains this script to another page that contains this script, onLoad will be
called again with a context of the new page's contents.

$3

This is where you will want to clean up after leaving a page. In this method, you should
remove any event listeners added the DOM elements in the onLoad method. If the new page
contains this script, context will be the old page's contents. If the new page does not
contain this script, context will be the document. In the latter case, onUnload
will be called before onDestroy.

$3

This method is called when a user navigates from a page that contains this script to one
that doesn't. This is where you will want to clean up any global event listeners attached
in the onInit method.