> ## Documentation Index
> Fetch the complete documentation index at: https://docs.appcharge.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Implement the Callbacks

## Callback methods

To implement the iOS Payment Links SDK, include the following callback methods:

| Method                 | Description                                                                                                                                                                                                                    | Argument         | Type                                   |   |
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------- | -------------------------------------- | - |
| `onInitialized`        | Triggered when SDK initialization was successful.                                                                                                                                                                              |                  |                                        |   |
| `onInitializeFailed`   | Triggered when SDK initialization failed.                                                                                                                                                                                      | `error`          | `ACErrorMessage`                       |   |
| `onPricePointsSuccess` | Triggered when the price points have successfully been retrieved.                                                                                                                                                              | `pricePoints`    | `PricePoints`                          |   |
| `onPricePointsFailed`  | Triggered when price points can’t be retrieved or are unavailable.                                                                                                                                                             | `error`          | `ACErrorMessage`                       |   |
| `onPurchaseSuccess`    | Triggered when a purchase was successful.                                                                                                                                                                                      | `order`          | `OrderResponseModel`                   |   |
| `onPurchaseFailed`     | Triggered when the checkout window closed or if a server to server error occurred during the purchasing process. Returns a unique integer error code, a detailed message, a raw JSON string (if available), and order details. | `error`, `order` | `ACErrorMessage`, `OrderResponseModel` |   |

### OrderResponseModel properties

The `OrderResponseModel` argument type contains the following properties:

| Property Name       | Type     | Description                                                    | Example                                              |
| ------------------- | -------- | -------------------------------------------------------------- | ---------------------------------------------------- |
| `date`              | `Int`    | Unix timestamp of the order.                                   | `1718182312`                                         |
| `sessionToken`      | `String` | Unique token for the current session.                          | `"xxxxXXXXxxxxXXXXxxxx"`                             |
| `offerName`         | `String` | Name of the purchased offer.                                   | `"Starter Pack"`                                     |
| `offerSku`          | `String` | SKU identifier for the offer.                                  | `"starter_pack_001"`                                 |
| `items`             | `[Item]` | List of items included in the purchase.                        | `[{ name: "Gems", sku: "gem_01", quantity: "100" }]` |
| `items.name`        | `String` | Display name of the item.                                      | `"Gems"`                                             |
| `items.sku`         | `String` | Unique SKU code for the item.                                  | `"gem_01"`                                           |
| `items.quantity`    | `String` | Quantity of the item included.                                 | `"100"`                                              |
| `price`             | `Int`    | Price of the order in minor units. For example, cents for USD. | `499`                                                |
| `currency`          | `String` | ISO 4217 currency code                                         | `"USD"`                                              |
| `customerId`        | `String` | ID of the customer who made the purchase.                      | `"cust_98765"`                                       |
| `customerCountry`   | `String` | Country code of the customer in ISO 3166-1 alpha-2 format.     | `"US"`                                               |
| `paymentMethodName` | `String` | Payment method.                                                | `"Visa"`                                             |
| `orderId`           | `String` | Order ID.                                                      | `"1234567890"`                                       |
| `purchaseId`        | `String` | A unique ID to track the transaction.                          | `"pr_xxxxxx"`                                        |

### ACErrorMessage  properties

The `ACErrorMessage` argument type contains the following properties:

| Property Name | Type     | Description                              | Example                                                               |
| ------------- | -------- | ---------------------------------------- | --------------------------------------------------------------------- |
| `code`        | `Int`    | Error code identifying the failure.      | `3002`                                                                |
| `message`     | `String` | Detailed message describing the failure. | `"Purchase canceled because the user closed the checkout interface."` |

## Example code

<CodeGroup>
  ```swift Swift theme={"system"}
  extension ViewController: ACPaymentLinksDelegate {
    func onInitialized() {
      print("SDK initialization was successful.")
    }
    func onInitializeFailed(error: ACErrorMessage) {
      print("SDK initialization failed: \(error)")
    }
    func onPricePointsSuccess(pricePoints: PricePoints) {
      print("Price points were successfully retrieved: \(pricePoints)")
    }
    func onPricePointsFailed(error: ACErrorMessage) {
      print("Price points were not available: \(error)")
    }
    func onPurchaseSuccess(order: OrderResponseModel) {
      print("Purchase was successful: \(order.orderId)")
    }
    func onPurchaseFailed(error: ACErrorMessage, order: GameOrderResponse?) {
      print("Purchase failed: \(order.orderId ?? "No order ID found.")")
    }
  }
  ```

  ```c Objective-C theme={"system"}
  @interface ViewController () <ACPaymentLinksDelegate>
  @end
  @implementation ViewController

  - (void)onInitialized {
      NSLog(@"SDK initialization was successful.");
  }

  - (void)onInitializeFailedWithError:(ACErrorMessage *)error {
      NSLog(@"SDK initialization failed: %@", error);
  }

  - (void)onPricePointsSuccessWithPricePoints:(PricePoints *)pricePoints {
      NSLog(@"Price points were successfully retrieved: %@", pricePoints);
  }

  - (void)onPricePointsFailedWithError:(ACErrorMessage *)error {
      NSLog(@"Price points were not available: %@", error);
  }

  - (void)onPurchaseSuccessWithOrder:(OrderResponseModel *)order {
      NSLog(@"Purchase was successful: %@", order.orderId);
  }

  - (void)onPurchaseFailedWithError:(ACErrorMessage *)error order:(GameOrderResponse * _Nullable)order {
    NSLog(@"Purchase failed: %@", order.orderId ?: @"No order ID found.");
  }
  @end
  ```
</CodeGroup>