How to continue an NSUserActivity in SwiftUI

Paul Hudson @twostraws June 24th 2020

Updated for Xcode 12.0

New in iOS 14

SwiftUI has a dedicated onContinueUserActivity() modifier that can catch a variety of NSUserActivity types – clicks from the web, launches from Spotlight or Siri, and more. Previously you might have handled this in your AppDelegate using something like application(_:continue:restorationHandler:), but SwiftUI’s approach is more fine-grained and lets us divide functionality more easily.

To implement this, first create a function that will accept an NSUserActivity. You don’t need to do this inside your App struct, but it would make sense to do so because you can then route it wherever you need in the rest of your program.

For example, this function checks to see whether we’re being passed in data from Spotlight, and if so pulls out the unique identifier so you can look it up in your data source:

func handleSpotlight(_ userActivity: NSUserActivity) {
    if let id = userActivity.userInfo?[CSSearchableItemActivityIdentifier] as? String {
        print("Found identifier \(id)")
    }
}

Note: That doesn’t need to check the activityType property, because it will be filtered by SwiftUI in our next code.

Now you can attach that to your main app’s view by modifying your App struct like this:

WindowGroup {
    ContentView()
        .onContinueUserActivity(CSSearchableItemActionType, perform: handleSpotlight)
}

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How to continue an NSUserActivity in SwiftUI

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