iOS8 check if device has Touch ID

Question

LAContext has method to check if device can evaluate touch ID and gives error message. Problem is that same error message \"LAErrorPasscodeNotSet\" is given by system in two cas

Answer 1

In Swift 3

fileprivate func deviceSupportsTouchId(success: @escaping () -> (), failure: @escaping (NSError) -> ()) {
    let context = LAContext()
    var authError: NSError?
    let touchIdSetOnDevice = context.canEvaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, error: &authError)

    if touchIdSetOnDevice {
        DispatchQueue.main.async {
             success()
        }
    }
    else {
        DispatchQueue.main.async {
             failure(error!)
        }
    }
}

deviceSupportsTouchId() return Success if the device has touch Id capability.

If not then, function will return error, giving you the following error code if touchIDNotEnrolled is not set yet.

LAError.Code.touchIDNotEnrolled.rawValue

You can handle it using this value.