Swift key paths compile error in Xcode 12.1 (12A7403)

Question

Created Oct ’20

Replies 2

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Hi,

I've tried upgrading my project from Xcode 11.7 (11E801a) to Xcode 12 through 12.1 (12A7403) and I keep hitting a compile error with this code:

Code Block swiftlet navigationBarControllerState: [PartialKeyPath<UINavigationController>: Any] = [\UINavigationController.isNavigationBarHidden: false,
                                                                                    \UINavigationController.navigationBar.barStyle: UIBarStyle.black,
                                                                                    \UINavigationController.navigationBar.isTranslucent: true,
                                                                                    \UINavigationController.navigationBar.tintColor: UIColor.white,
                                                                                    \UINavigationController.hidesBarsOnTap: true]

Here's the error:

Sources/Controllers/CompareViewController.swift:285:96: error: value of type 'UIViewController' has no member 'navigationBar' \UINavigationController.navigationBar.tintColor: UIColor.white,

The same code compiles correctly in Xcode 11 and I've tried it in the Playgrounds app where it also compiles without error.

I've made no other changes to the project.

Any help appreciated.

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Answer 1

OOPer OP

Oct ’20

The same error occurs in Xcode 12.0.1. And I cannot find why Swift compiler does not like tintColor.

In my opinion, this is a bug of Swift compiler and you should better send a feedback.

A possible workaround. (Only tested in 12.0.1.)
Declare the key somewhere else.

Code Block     static let tintColorKey: PartialKeyPath<UINavigationController> = \UINavigationController.navigationBar.tintColor
    let navigationBarControllerState: [PartialKeyPath<UINavigationController>: Any] = [
        \UINavigationController.isNavigationBarHidden: false,
        \UINavigationController.navigationBar.barStyle: UIBarStyle.black,
        \UINavigationController.navigationBar.isTranslucent: true,
        tintColorKey: UIColor.white,
        \UINavigationController.hidesBarsOnTap: true
    ]

(static may not be needed depending on where you declare navigationBarControllerState.

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Answer 2

cyber.sonik OP

Oct ’20

Thanks for confirming OOPer and the workaround. I've also been able to change the variable to a var and do this:

Code Block swiftnavigationBarControllerState[\UINavigationController.navigationBar.tintColor] = UIColor.white

I submitted this as a bug in the Feedback Assistant too.

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