IBAction and IBOutlet

Gone are the days of switching back and forth between .h and .m files! And one of the tangible benefits of a single file per class is easy access to IBAction and IBOutlet declarations.

In Objective-C your .h would probably have a bit of this:

@interface MyViewController: UIViewController

@property (weak) IBOutlet UIButton *likeButton;
@property (weak) IBOutlet UILabel *instructions;
- (IBAction)likedThis:(id)sender;

@end

And then you constantly have to dig into your .h file when playing with storyboards to tweak names. Blah.

Simplicity rules in swift. If you have a property defined that you want to make accessible to your storyboards, just add the @IBOutlet attribute before your property. Similarly with @IBAction to connect storyboard actions back to code.

class MyViewController: UIViewController {
  @IBOutlet weak var likeButton: UIButton?
  @IBOutlet weak var instruction: UILabel?

  @IBAction func likedThis(sender: UIButton) {
    ...
  }
}

There are other interesting attributes that you can apply in swift but for now we’ll just cover these two common interface builder ones. There are two new interface builder attributes @IBDesignable and @IBInspectable which we probably won’t cover as their usage is very similar to this.

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