---
title: Step 3. Authenticating with external IdPs
description: PingOne iOS
component: orchsdks
page_id: orchsdks:davinci:use-cases/external-idp/ios/03_authenticate_with_external_idps
canonical_url: https://developer.pingidentity.com/orchsdks/davinci/use-cases/external-idp/ios/03_authenticate_with_external_idps.html
revdate: Tue, 25 Mar 2025 11:00:37 +0100
keywords: ["DaVinci", "Flows", "Tutorial", "Source Code", "Integration", "SDK", "iOS"]
---

# Step 3. Authenticating with external IdPs

[icon: circle-check, set=far]PingOne [icon: apple, set=fab]iOS

Your app must handle the `IdpCollector` your server returns when it is time to authenticate using an external IdP.

Call `authorize()` to begin authentication with the external IdP when encountering this callback as follows:

```swift
public class SocialButtonViewModel: ObservableObject {
    @Published public var isComplete: Bool = false
    public let idpCollector: IdpCollector

    public init(idpCollector: IdpCollector) {
        self.idpCollector = idpCollector
    }

    public func startSocialAuthentication() async -> Result<Bool, IdpExceptions> {
        return await idpCollector.authorize()
    }

    public func socialButtonText() -> some View {
        let bgColor: Color
        switch idpCollector.idpType {
        case "APPLE":
            bgColor = Color.appleButtonBackground
        case "GOOGLE":
            bgColor = Color.googleButtonBackground
        case "FACEBOOK":
            bgColor = Color.facebookButtonBackground
        default:
            bgColor = Color.themeButtonBackground
        }
        let text = Text(idpCollector.label)
            .font(.headline)
            .foregroundColor(.white)
            .padding()
            .frame(width: 300, height: 50)
            .background(bgColor)
            .cornerRadius(15.0)

        return text
    }
}
```

The `authorize()` method returns a `Success` result when authentication with the external IdP completes successfully. If not, it returns `Failure` and `IdpExceptions`, which shows the root cause of the issue.

```swift
Task {
    let result = await socialButtonViewModel.startSocialAuthentication()
    switch result {
    case .success(_):
        onNext(true)
    case .failure(let error): //<- Exception
        onStart()
    }
}
```

The result resembles the following:

![Example iOS app with social sign-on options.](../../../_images/davinci-social-sign-on-ios-example.png)