Xcode 9 : Block Based KVO Violation for observeValue function

Question

I’ve SwiftLint enabled in project and it throws an warning for below function :

override func observeValue(forKeyPath keyPath: String?, of _: Any?, change: [NSKeyValueChangeKey: Any]?, context _: UnsafeMutableRawPointer?) {
    . . .
}

Shell Script Invocation Warning : Block Based KVO Violation : Prefer the new block based KVO API with key paths when using Swift 3.2 or later.

Any fix for this?

The warning suggests the fix. However it's just a warning and harmless. — vadian, Apr 10 '18 at 07:16
Check this https://stackoverflow.com/questions/46324089/swift-4-using-kvo-to-listen-to-volume-changes/46324383 — Pandey_Laxman, Apr 10 '18 at 07:21
This could help you https://github.com/realm/SwiftLint/issues/1989 additionally this too https://github.com/aguilarpgc/KVO — Vinaykrishnan, Apr 10 '18 at 07:29

score 10 · Answer 1 · answered Dec 25 '18 at 22:23

10

A good tutorial to make Block Base KVO Here

class CounterModel : NSObject {

    @objc dynamic var value = 0
    @objc dynamic var messages = [String]()

}


model.observe(\.value, options: [.initial]) { (model, change) in
    self.label.text = String(model.value)
}

answered Dec 25 '18 at 22:23

dimohamdy

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4

Your link is broken. – Caleb Dec 14 '22 at 07:06

Xcode 9 : Block Based KVO Violation for observeValue function

1 Answers1