Sn0wfreeze
Sn0wfreeze

Reputation: 2031

How to signal errors / failures in iOS App Intents?

the new AppIntents allow a simple code-driven implementation for Siri Shortcuts. In the perform() function we need to return some IntentResult or throw an error if something went wrong.

My question now is: How do I throw an error that can then be inspected by the user? Let's say the user wants to interact with a CoreData object that he has deleted earlier. Now he/she runs the shortcut and it must fail, because the object is not available. I tried to implement a custom LocalizedError, but in the Shortcuts app I only get an error message telling me something about an unknown error. The description text is not shown in Shortcuts.

Feedback ID: FB11434135

Kind regards
Alex

Upvotes: 2

Views: 819

Answers (1)

Klaas
Klaas

Reputation: 22773

I couldn't find any documentation on this, but during the migration of my intents I ended up using a property localizedStringResource like this:

struct MyIntent: AppIntent {
    static let title: LocalizedStringResource = "Start My Intent"

    func perform() async throws -> some IntentResult {

        if !doSomething() {
            throw MyIntentError.message("Hello, I'm an error!")
        }
        
        return .result(dialog: IntentDialog("My answer"))
    }
    
    func doSomething() -> Bool {
        return false
    }
}

enum MyIntentError: Swift.Error, CustomLocalizedStringResourceConvertible {
    case general
    case message(_ message: String)

    var localizedStringResource: LocalizedStringResource {
        switch self {
        case let .message(message): return "Error: \(message)"
        case .general: return "My general error"
        }
    }
}

Upvotes: 4

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