What is the File's Owner (in Interface builder)?

Question

I am new to Cocoa and I don\'t understand the concept of File\'s Owner of a .nib file.

Here is the way I would see things :

• Consider a

Answer 1

The fundamental thing to understand is that Interface Builder allows you to create objects that are automatically connected to each other, with no effort on the part of your program. You can instantiate all kinds of objects including non-view ones, and they can be inter-related; for example, you might create the instance of a table view data source along with the view itself, etc. This mechanism is commonly used to create an Application Delegate within your Main Menu NIB.

However, since it's all done via drag&drop, it seems there is no way that you can form a connection between any of the NIB objects and the objects that already exist in your application, with one exception.

When code is loading the NIB file, you have the option to specify exactly one object which the NIB will consider to be the "Files Owner". This is the placeholder that you see inside Interface Builder; since it can represent any object within your application, Interface Builder can't know what actions/outlets are available on it. This is why you can modify the "class" of the Files Owner, in the Attributes tab.

Files Owner does not really represent "ownership" or "parenthood". What it represents is "the object that loaded this NIB".