add_action, do_action in Javascript

actions.js

function add_action( action_name, callback, priority ) {
	if ( ! priority )  {
		priority = 10;
	}
	
	if ( priority > 100 ) {
		priority = 100;
	} 
	
	if ( priority < 0 ) {
		priority = 0;
	} 
	
	if ( typeof actions[action_name] == 'undefined' ) {
		actions[action_name] = [];
	}
	
	if ( typeof actions[action_name][priority] == 'undefined' ) {
		actions[action_name][priority] = []
	}
	
	actions[action_name][priority].push( callback );
}


function do_action() {
	if ( arguments.length == 0 ) {
		return;
	}
	
	var args_accepted = Array.prototype.slice.call(arguments),
		action_name = args_accepted.shift(),
		_this = this,
		i,
		ilen,
		j,
		jlen;
	
	if ( typeof actions[action_name] == 'undefined' ) {
		return;
	}
	
	for ( i = 0, ilen=100; i<=ilen; i++ ) {
		if ( actions[action_name][i] ) {
			for ( j = 0, jlen=actions[action_name][i].length; j<jlen; j++ ) {
				actions[action_name][i][j].apply( _this, args_accepted );
			}
		}
	}
}

Peter and @BronsonQuick refer to http://core.trac.wordpress.org/ticket/21170

Peter and @BronsonQuick refer to http://core.trac.wordpress.org/ticket/21170