Detected redundant observation of

[devkokodev]

I use gestalt same as you describe in Usage part. I don't use storyboard or xib (entire project is in code). I have custom views in my controller and every view has it's own theme also controller. When i push or present controller for first time everything is fine, but if i pop or dissmiss and push again i get "Detected redundant observation" from some view or controller. I looked up in your demo project and in appdelegate there is var disposables: [Disposable]?. I haven't implement that stuff. I check for retain cycle all views and controller deinitialized properly. Any help for Detected redundant observation??

[regexident]

self.observe(theme: \Theme.view) should only ever be called once within the lifetime of an object (i.e. self here).

Handling Disposable is only necessary for the class-level API.

[devkokodev]

i tried on demo project with only two controllers this is logs

*** 0x0000000103106690 Firs view controller regiseter for theme first theme
*** 0x0000000103121190 Second view controller regiseter for theme second theme
*** 0x0000000103121190 Second view controller deinit
*** 0x0000000103113540 Second view controller regiseter for theme second theme
*** 0x0000000103113540 Second view controller deinit
*** 0x000000010301eda0 Second view controller regiseter for theme second theme
*** 0x000000010301eda0 Second view controller deinit
*** 0x000000010301eda0 Second view controller regiseter for theme second theme
*** 0x000000010301eda0 Second view controller deinit
*** 0x000000010301eda0 Second view controller regiseter for theme second theme
*** 0x000000010301eda0 Second view controller deinit
*** 0x000000010301eda0 Second view controller regiseter for theme second theme
*** 0x000000010301eda0 Second view controller deinit
*** 0x0000000103113540 Second view controller regiseter for theme second theme
*** 0x0000000103113540 Second view controller deinit

As you can see few times second view contoller has same memory address

App delegate:
window = UIWindow(frame: UIScreen.main.bounds) window?.rootViewController = UINavigationController(rootViewController: FirstViewController()) window?.makeKeyAndVisible() ThemeManager.default.theme = ApplicationTheme.light

First view controller:
`class FirstViewController: UIViewController, Themeable {

var pushButton = UIButton(frame: CGRect(x: 100, y: 500, width: 100, height: 50))

override func viewDidLoad() {
    super.viewDidLoad()
    pushButton.setTitle("push", for: .normal)
    pushButton.setTitleColor(.black, for: .normal)
    pushButton.addTarget(self, action: #selector(onPush), for: .touchUpInside)
    view.addSubview(pushButton)
    setThemeObserve()
}


    typealias Theme = FirstVCTheme

    func setThemeObserve() {
        self.observe(theme: \ApplicationTheme.firstTheme)
        print("*** \(Unmanaged.passUnretained(self).toOpaque()) Firs view controller regiseter for theme first theme")
    }

    func apply(theme: Theme) {
        view.backgroundColor = theme.backgroundColor
    }

@objc func onPush() {
    self.navigationController?.pushViewController(SecondViewController(), animated: true)
}

}`

Second view controller: `class SecondViewController: UIViewController, Themeable {

override func viewDidLoad() {
    super.viewDidLoad()

    setThemeObserve()
}

deinit {
    print("*** \(Unmanaged.passUnretained(self).toOpaque()) Second view controller deinit")
}

    typealias Theme = SecondVCTheme

    func setThemeObserve() {
        self.observe(theme: \ApplicationTheme.secondTheme)
        print("*** \(Unmanaged.passUnretained(self).toOpaque()) Second view controller regiseter for theme second theme")
    }

    func apply(theme: Theme) {
        view.backgroundColor = theme.backgroundColor
    }

}`

AplicationTheme:
`enum ThemeType: Int {
case light
case dark
}

struct ApplicationTheme: Theme {

let firstTheme: FirstVCTheme
let secondTheme: SecondVCTheme

static let light = ApplicationTheme(firstTheme: FirstVCTheme(type: .light),
                                    secondTheme: SecondVCTheme(type: .light))
                                   

static let dark = ApplicationTheme(firstTheme: FirstVCTheme(type: .dark),
                                   secondTheme: SecondVCTheme(type: .dark))

}

struct SecondVCTheme: Theme {
let backgroundColor: UIColor

init(type: ThemeType) {
    switch type {
    case .light:
        backgroundColor = .cyan
    case .dark:
        backgroundColor = .brown
    }
}

}

struct FirstVCTheme: Theme {
let backgroundColor: UIColor

init(type: ThemeType) {
    switch type {
    case .light:
        backgroundColor = .red
    case .dark:
        backgroundColor = .yellow
    }
}

}`

[regexident]

If you get "Detected redundant observation" with func viewDidLoad(), then try moving self.observe(theme: …) into the initializer instead.