Garber-Irish DOM-Based module loading

loader.js

var APP = {
  common: {
    init: function() {
      // application-wide code
    }
  }
};

window.UTIL = {
  exec: function( controller, action ) {
    var ns = APP,
        action = ( action === undefined ) ? 'init' : action;

    if ( controller !== '' && ns[controller] && typeof ns[controller][action] == 'function' ) {
      ns[controller][action]();
    }
  },

  init: function() {
    var body = document.body,
        controller = body.getAttribute( 'data-controller' ),
        action = body.getAttribute( 'data-action' );

    UTIL.exec( 'common' );
    UTIL.exec( controller );
    UTIL.exec( controller, action );
  }
};

window.UTIL.init();