Why IBInspectable not set vaue for optional variable from storyboard?

Question

I am making a demo for learning how @IBInspectable works.

First, I made two variables in UIViewController subclass:

  @IBInspectable var intTest:Int = 10
  @IBInspectable var flag:Bool = false

So that it appears in the storyboard. After that, I change the value of those variables in the storyboard:

Then, I try to print those variables in "viewDidLoad()" method like this:

  override func viewDidLoad() {
       super.viewDidLoad()
       // Do any additional setup after loading the view, typically from a nib.
       print("intTest value: \(String(describing: intTest))")
       print("flag value: \(String(describing: flag)))")
  }

The output is:

intTest value: 90

flag value: true

It works fine, except when I change the variables declaration like,

  @IBInspectable var intTest:Int? = 10
  @IBInspectable var flag:Bool? = false

After that, I changed the value same as above in the storyboard, but the values are not changed.

Output is:

intTest value: Optional(10)

flag value: Optional(false)

So my question is, why is the value not updated when i declare the variable as optional?

The another thing is, when I take the variable as a string the value is updated. Can anyone help me understand this functionality?

Harshal Valanda · Answer 1 · 2017-05-04T05:31:55.903

4

Set Optional value IBInspectable var

@IBInspectable var placeHolderImage:UIImage? {
     didSet {
         leftViewSetting()
     }
 }

Set default value IBInspectable var

@IBInspectable var placeHolderImage:UIImage = UIImage() {
    didSet {
        leftViewSetting()
    }
}

Using this approach and every time you change the value in Interface Builder`, your view will be updated.

@IBInspectable var cornerRadius: CGFloat {
    get {
       return layer.cornerRadius
    }
    set {
       layer.cornerRadius = newValue
    }
}

edited May 04 '17 at 05:31

answered May 04 '17 at 05:21

Harshal Valanda

5,331
26
63

I know that when we declare a variable as optional then the value is not updated but my question is why? – vikas prajapati May 04 '17 at 05:28
`@IBInspectable var placeHolderImage:UIImage?` i change IBInspectable var to option its working well. Update your question with your designable class. – Harshal Valanda May 04 '17 at 05:43
Yes, I found that image is updating same as String.But, my question is why Int and Bool value are not updating? – vikas prajapati May 04 '17 at 08:44

score -1 · Answer 2 · edited May 23 '17 at 12:18

-1

You can declare it as an optional and it works well . Just tweak your code as below:

 @IBInspectable var intTest: Int? {
        didSet {
            self.intTestTweak = intTest
        }
  }

willSet and didSet are explained here.

edited May 23 '17 at 12:18

Community

1
1

answered May 04 '17 at 05:10

ankit

3,537
1
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Why IBInspectable not set vaue for optional variable from storyboard?

2 Answers2