How to detect First launch of app on every new version upgrade?

Question

I have a requirement of detecting the first launch of app after the user upgrades the app to a newer version. I need to perform certain task only on first launch of app after the user upgrades the app to a new version. Many links available online but none answer clearly to my query. How to achieve this in Swift 2 , iOS 9.

Most of the answers available says to maintain a key in NSUserDefaults and set its value to false and after first launch make it true. But the problem is after I upgrade my app the variable still will be true and thus my scenario fails on app upgrade. Any help would be much appreciated. Thanks!

Just do the same, but instead of saving a boolean, save the build/app version. It's in your Info.plist: http://stackoverflow.com/questions/1492351/how-to-display-the-current-project-version-of-my-app-to-the-user Read it, if it's the same, no update, if not, new version, and write it. — Larme, Oct 13 '16 at 12:30
@Larme Thanks! But, Can you describe in little more detail please? If I am not wrong you mean to say that, I should compare the version, and if there is change in version number then this task runs, else not. Is that correct? — Tejas, Oct 13 '16 at 12:34
In pseudo code, this should to the trick: `savedVersion = readStringVersionFromUserDefault(); currentVersion = readStringVersionFromBundlePlist(); if (savedVersion.isNil or currentVersion != savedVersion){firstTimeUserLaunchedThisVersion(); saveStringVersionFromBundlePlistIntoUserDefaults();}else{UserHasAlreadyLaunchedThisVersion}` — Larme, Oct 13 '16 at 12:53

score 3 · Answer 1 · answered Oct 14 '16 at 11:15

Try this:

    let existingVersion = NSUserDefaults.standardUserDefaults().objectForKey("CurrentVersionNumber") as? String
    let appVersionNumber = NSBundle.mainBundle().objectForInfoDictionaryKey("CFBundleShortVersionString") as! String

    if existingVersion !=  appVersionNumber {
        NSUserDefaults.standardUserDefaults().setObject(appVersionNumber, forKey: "CurrentVersionNumber")
        NSUserDefaults.standardUserDefaults().synchronize()
       //You can handle your code here
    }

score 3 · Answer 2 · answered Nov 27 '18 at 17:12

updating Yogesh's perfect, yet simple solution to swift 4

    let existingVersion = UserDefaults.standard.object(forKey: "CurrentVersionNumber") as? String
    let appVersionNumber = Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as! String

    if existingVersion != appVersionNumber {
        print("existingVersion = \(String(describing: existingVersion))")
        UserDefaults.standard.set(appVersionNumber, forKey: "CurrentVersionNumber")

 // run code here.

    }

How to detect First launch of app on every new version upgrade?

2 Answers2