Function that detects an app uninstall/reinstall

Question

Been looking around to find a way to detect when an app is uninstalling/reinstalling. The thing is, I do not use NSUserDefaults, I use SwiftKeychainWrapper.

I need to clear that user's keychain when app uninstalls.

didFinishLaunchingWithOptions seems to call when app loads so no use there. Is there a way to detect a reinstall? I need to call this:

return KeychainWrapper.standard.removeObject(forKey: "myKey") // only when/if app is unsinstalled/reinstalling

score 3 · Accepted Answer · edited Feb 13 '17 at 16:19

3

Presumably you're using Keychain because you need to store sensitive information? If so then you could just store a boolean in UserDefaults and check if that exists. For example:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    let freshInstall = !UserDefaults.standard.bool(forKey: "alreadyInstalled")
    if freshInstall {
        // delete your item from keychain
        UserDefaults.standard.set(true, forKey: "alreadyInstalled")
    }

    return true
}

This way you still have the security of the Keychain, but the behaviour of UserDefaults on uninstall/reinstall.

edited Feb 13 '17 at 16:19

FelixSFD

6,052
10
43
117

answered Feb 13 '17 at 16:18

Jacob King

6,025
4
27
45

Thanks. There seem to be an issue with SwiftKeychainWrapper; your method do called at the correct time so hence I make this answer correct. Thanks. – Sylar Feb 13 '17 at 16:44
This code doesn't provide an information that contains a reinstallation or uninstallation of an app. It just tells you that I'm a new app. – aytek Feb 13 '17 at 17:25
@ayteq Completely true, however unfortunately there is no way to invoke code when your app is deleted on non-jailbroken devices, this approach achieves the same goal in a roundabout way however, and the OP did specify in his question that checking upon re-install was fine for his scenario. – Jacob King Feb 14 '17 at 07:51

score 1 · Answer 2 · answered Jun 24 '17 at 11:10

1

for others searching for the way to clear the Keychain in the "// delete your item" part of the answer.....

Swift 3

let _ = KeychainWrapper.standard.removeAllKeys()

answered Jun 24 '17 at 11:10

Apps-n-Add-Ons

2,026
1
17
28

Function that detects an app uninstall/reinstall

2 Answers2