# The Onside Delegate

`OnsideDelegate` lets you tune how OnsideKit presents its screens and routes login. Every method has a default implementation, so implement only the ones you need.

```swift
protocol OnsideDelegate: AnyObject {
    @MainActor func onside(hostWindowSceneForScreen screen: OnsideScreen) -> UIWindowScene?
    @MainActor func onside(uiThemeOverrideForScreen screen: OnsideScreen) -> OnsideUIThemeMode?
    @MainActor func onsideShouldForceLocalLoginMethods() -> Bool
    @MainActor func onsideDefaultCountryCodeAssumption() -> String?
}
```

Assign your delegate (keep a strong reference — it's held weakly), typically at launch:

```swift
@main
final class AppDelegate: UIResponder, UIApplicationDelegate, OnsideDelegate {
    func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
    ) -> Bool {
        Onside.initialize()
        Onside.delegate = self
        return true
    }
}
```

## OnsideScreen

Several delegate methods receive the screen OnsideKit is about to present:

```swift
enum OnsideScreen {
    case login                   // the user authentication screen
    case paymentMethodsManager   // the saved-cards management screen
    case profileInfoFulfillment  // a step that collects/confirms profile info (e.g. region) during a purchase
    case purchase                // the purchase flow
}
```

## Host window scene

```swift
func onside(hostWindowSceneForScreen screen: OnsideScreen) -> UIWindowScene?
```

Return the `UIWindowScene` in which OnsideKit should present the given screen — useful in multi-window apps. If you return `nil` (the default), OnsideKit uses the first active connected scene.

```swift
func onside(hostWindowSceneForScreen screen: OnsideScreen) -> UIWindowScene? {
    return preferredScene   // or nil to use the default
}
```

{% hint style="warning" %}
If no connected window scene is available, OnsideKit cannot present its UI and the screen is not shown.
{% endhint %}

## Per-screen theme override

```swift
func onside(uiThemeOverrideForScreen screen: OnsideScreen) -> OnsideUIThemeMode?
```

Force a theme for a specific screen, overriding the [global theme](/sdk/customization/appearance.md) and the system appearance:

* `.light` / `.dark` — force that theme
* `.auto` — follow the system setting
* `nil` (default) — no override; fall back to the global theme, then the system theme

```swift
func onside(uiThemeOverrideForScreen screen: OnsideScreen) -> OnsideUIThemeMode? {
    screen == .login ? .dark : nil
}
```

## Force in-SDK login

```swift
func onsideShouldForceLocalLoginMethods() -> Bool
```

By default OnsideKit prefers the app-to-app login via the Onside store app. Return `true` to always use OnsideKit's own in-app login screen instead. It is purely a UI-routing switch — it doesn't change which credentials are accepted. Default: `false`. See [Authentication & User Account](/sdk/core-concepts/authentication.md).

## Pre-login region hint

```swift
func onsideDefaultCountryCodeAssumption() -> String?
```

Provide an ISO 3166-1 alpha-2 country code (e.g. `"US"`, `"DE"`) to use as the region **before** the user logs in, improving logged-out pricing and availability. Return `nil` (default) to use the device region. Once the user logs in, the account's region is used and this hint is ignored. See [Regions & Storefronts](/sdk/products-and-subscriptions/regions-and-storefronts.md).


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