Hello,
there is a better place where an object can be registered to a Notification Center?
In other words, for a matter of performance, it's a good practice to register an object as Notification listener in the init(), awakeFromNib() or other event handler?
Thanks!
There's not really any performance difference you'll be able to notice by registering for notifications at a different time. The only advice I can give you is to narrow the window that a notification is being observed to as short a duration as possible. Also, make sure you only register an observer once. If you register an observer multiple times, you'll get multiple notifications.
Why are you so concerned about the performance of notifications? Have you confirmed that notifications are causing a problem by measuring?
Do not worry about performance until your code is working and you can observe and measure any performance issues you may have. Registering observers is something done quite infrequently, so there should be no significant performance issues involved in when you do so. What can be significant is how many objects you register for notifications and how many notifications you're sending, since posting notifications involves a hash lookup.