NSObject UIKit Additions Reference
Available in iOS 2.0 and later.
This category adds methods to the Foundation framework’s
NSObject class. The method in this category provides support for loading nib files into your application.
Responding to Being Loaded from a Nib File
Prepares the receiver for service after it has been loaded from an Interface Builder archive, or nib file.
The nib-loading infrastructure sends an
awakeFromNib message to each object recreated from a nib archive, but only after all the objects in the archive have been loaded and initialized. When an object receives an
awakeFromNib message, it is guaranteed to have all its outlet and action connections already established.
You must call the
super implementation of
awakeFromNib to give parent classes the opportunity to perform any additional initialization they require. Although the default implementation of this method does nothing, many UIKit classes provide non-empty implementations. You may call the
super implementation at any point during your own
During the instantiation process, each object in the archive is unarchived and then initialized with the method befitting its type. Objects that conform to the
NSCoding protocol (including all subclasses of
UIViewController) are initialized using their
initWithCoder: method. All objects that do not conform to the
NSCoding protocol are initialized using their
init method. After all objects have been instantiated and initialized, the nib-loading code reestablishes the outlet and action connections for all of those objects. It then calls the
awakeFromNib method of the objects. For more detailed information about the steps followed during the nib-loading process, see Nib Files and Cocoa in Resource Programming Guide.
Typically, you implement
awakeFromNib for objects that require additional set up that cannot be done at design time. For example, you might use this method to customize the default configuration of any controls to match user preferences or the values in other controls. You might also use it to restore individual controls to some previous state of your application.
- Available in iOS 2.0 and later.
© 2008 Apple Inc. All Rights Reserved. (Last updated: 2008-03-26)