Code to open main app from share extension

OpenAppFromExtension.swift

// A way to open main app from share extension. Verified on iOS 15-26 and macOS 15
private func openApp() {
    // For this to work the app needs to have an url scheme: https://developer.apple.com/documentation/xcode/defining-a-custom-url-scheme-for-your-app
    // Potential alternative is also to use universal links: https://developer.apple.com/documentation/xcode/allowing-apps-and-websites-to-link-to-your-content
    let url = URL(string: "myApp://")!
    #if os(iOS)
    if #available(iOS 18.0, *), openURL(url) {
        return
    }
    OpenURLAction.system(url)
    #else
    NSWorkspace.shared.open(url)
    #endif
}

#if os(iOS)
@available(iOS 18, *)
private func openURL(_ url: URL) -> Bool {
    let responser = sequence(first: self, next: \.next)
        .first(where: { $0 is UIApplication })
    if let application = responser as? UIApplication {
        application.open(url, options: [:], completionHandler: nil)
        return true
    }
    return false
}
#endif