This part of the documentation will help you understand the Javascript codebase.
1. loader.js : This is primary important JS File. It loades a JS object that holdes the information about the demo.
window.addEventListener("load", function(){
// Remove Loader
var load_screen = document.getElementById("load_screen");
document.body.removeChild(load_screen);
var layoutName = 'Collapsible Dark Menu';
var settingsObject = {
............
............
............
}
})
2. app.js : This is secondary important JS File. It is necessary for the layout to work.
var App = function() {
}();
window.addEventListener('load', function() {
App.init('layout');
})