CODEWITHSUNDEEP
ioscore-datansuserdefaultspreload
Adam Zarn
Adam Zarn

Reputation: 2100

Replace Preloaded Data when App is Updated - iOS Swift

I have an app that preloads a CSV file into Core Data when the app is launched for the first time like so: 

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    let isPreloaded = defaults.bool(forKey: "isPreloaded")
    if !isPreloaded {
        preloadData()
        defaults.set(true, forKey: "isPreloaded")
    }
}

However, I want to preload a new updated CSV file when the app is updated. I suppose I could create a new key called "isPreloaded2" in my defaults, but the CSV file is going to change with every update and I was wondering if there's a better way.

Upvotes: 0

Views: 370

Answers (2)

Adam Zarn
Adam Zarn

Reputation: 2100

Thanks to JoRa for his solution. For anyone who's interested, here's how I implemented it in Swift:

Swift 3.0

let defaults = UserDefaults.standard
if let version = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String {
    let currentVersion = defaults.value(forKey: "currentVersion") as? String
    if version != currentVersion { //currentVersion will either be nil or last version number when app is launched after update.
        preloadData()
        defaults.set(version, forKey: "currentVersion") //update currentVersion in defaults so version will match currentVersion next time.
    }
}

And don't forget to remove old data before you preload new data as well (my preloadData() function includes a removeData() function).

Upvotes: 1

jraufeisen
jraufeisen

Reputation: 3877

Maybe you could create a key lastUpdatedVersion in the userDefaults for checking which version has already been updated. Then you can check something like:

let currentVersion = Bundle.main.infoDictionary?["CFBundleShortVersionString"]
if !NSUserDefaults.standardUserDefaults.objectForKey(key: "lastVersionUpdated") || NSUserDefaults.standardUserDefaults.objectForKey(key: "lastVersionUpdated") != currentVersion     
{
    //Update your CSV here
    //...
    NSUserDefaults.standardUserDefaults.setObjectForKey(key: "lastVersionUpdated", object: currentVersion)
}

But it's still up to you to decide, whether this is an elegant solution or not.

Upvotes: 0

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