SignIn

The SignIn component renders a full app-native sign-in form. It drives the Flow Execution API loop automatically — initiating the flow, presenting the server-defined inputs and actions on each step, and completing when the user is authenticated.

SignIn requires .thunderIDProvider(config:) in its ancestor view hierarchy.

Usage

import SwiftUI
import ThunderIDSwiftUI

struct AuthView: View {
    var body: some View {
        SignIn(applicationId: "<your-application-id>")
            .padding()
    }
}

Parameters

Parameter	Type	Required	Description
applicationId	String	✅	The Application ID from your ThunderID application settings. Identifies which sign-in flow to execute.
onComplete	(() -> Void)?	❌	Called when authentication completes successfully.
onError	((String) -> Void)?	❌	Called with an error message when a flow step fails.

Handling Completion

Use onComplete to navigate away from the sign-in screen after a successful sign-in. ThunderIDState.user is updated automatically before this callback fires.

struct AuthView: View {
    @EnvironmentObject var state: ThunderIDState

    var body: some View {
        SignIn(
            applicationId: "<your-application-id>",
            onComplete: {
                // state.isSignedIn is now true; navigate to your home screen
            },
            onError: { errorMessage in
                print("Sign-in error: \(errorMessage)")
            }
        )
    }
}

Customization with BaseSignIn

BaseSignIn is the unstyled builder variant. It manages the Flow Execution loop and passes a SignInState object to your content closure, giving you full control over the form's appearance.

import SwiftUI
import ThunderIDSwiftUI

struct CustomSignInView: View {
    var body: some View {
        BaseSignIn(applicationId: "<your-application-id>") { signInState in
            VStack(spacing: 16) {
                if let error = signInState.error {
                    Text(error).foregroundStyle(.red)
                }

                ForEach(signInState.inputs, id: \.name) { input in
                    if input.type == "PASSWORD_INPUT" {
                        SecureField(input.name, text: signInState.binding(for: input.name))
                    } else {
                        TextField(input.name, text: signInState.binding(for: input.name))
                    }
                }

                ForEach(signInState.actions, id: \.id) { action in
                    Button(action.label ?? "Submit") {
                        signInState.submit(actionId: action.id)
                    }
                    .disabled(signInState.isLoading)
                }
            }
        }
    }
}

SignInState Properties

SignInState is passed to the BaseSignIn content closure and exposes the current flow step.

Property	Type	Description
inputs	[FlowInput]	Input fields to render for the current step. Each has a name, type, and required flag.
actions	[FlowAction]	Submit buttons to render. Each has an id and an optional label.
isLoading	Bool	true while a network request is in progress.
error	String?	Error message from the last failed step. nil on success.

SignInState Methods

Method	Description
binding(for:)	Returns a Binding<String> for the named input field.
submit(actionId:)	Submits the current field values with the given action ID.