AppVersionMonitor

To begin monitoring app versions, call startup() on the AppVersionMonitor.sharedMonitor instance, typically within your AppDelegate's applicationDidFinishLaunching method.

// AppDelegate

func applicationDidFinishLaunching(application: UIApplication) {
    AppVersionMonitor.sharedMonitor.startup()
}

Add AppVersionMonitor to your Podfile to integrate the library into your iOS project. Requires iOS 8.0 or higher and follows Semantic Versioning.

pod "AppVersionMonitor"

The AppVersion type supports comparison operators (>, <) against other AppVersion instances or raw version strings. This allows you to check if the current version is newer or older than a specific target.

AppVersion.marketingVersion > AppVersion("1.2.3")
AppVersion("1.2.3") < AppVersion("3.2.1")
AppVersion("1.2.3") < "3.2.1"

Use AppVersionMonitor.sharedMonitor.state to determine the relationship between the current installation and previous versions. This is useful for triggering data migrations or tutorials.

Available states:

• .Installed: The app was just installed (first time).
• .NotChanged: The version is the same as the previous installation.
• .Upgraded(previousVersion: AppVersion): The app version has increased. Use this to trigger data migrations.
• .Downgraded(previousVersion: AppVersion): The app version has decreased. Use this to purge incompatible data.

switch AppVersionMonitor.sharedMonitor.state {
case .Installed:
    // Start tutorial

case .NotChanged:
    // Nothing to do

case .Upgraded(let previousVersion: AppVersion):
    // Migrate App Data

case .Downgraded(let previousVersion: AppVersion):
    // Purge App Data
}

Access the list of previously installed versions using AppVersionMonitor.sharedMonitor.installedVersions. This returns an array of AppVersion objects.

let installedVersions: [AppVersion] = AppVersionMonitor.sharedMonitor.installedVersions

Use AppVersion.marketingVersion to retrieve the current app's version (corresponding to CFBundleShortVersionString). You can access the raw string representation via the .versionString property.

let currentVersion: AppVersion = AppVersion.marketingVersion
let versionString: String = AppVersion.marketingVersion.versionString // "1.2.3"