To use Post Purchase SDK in your application, you need to create an instance of the SDK and perform some operations on it. You can read more about the flow here.

This guide will teach you how to:

• Create an instance of the SDK and initialize it
• Get user’s consent for sharing their information 
• Fetching user purchases and render an operation for a specific order

To create an instance of the SDK, you need to provide the following parameters:

let postPurchaseSDK = KlarnaPostPurchaseSDK(
               environment: .playground,
               region: .eu,
               resourceEndpoint: .alternative1,
               listener: listenerObject
)

The listener is an object conforming to the protocol KlarnaPostPurchaseEventListener that you need to implement and pass to the SDK so you can receive the results for each operation you perform via the SDK.

If needed, you can add a new listener later on to the SDK. This will replace the current listener that was provided when constructing the SDK instance:

postPurchaseSDK.setEventListener(listener)

You can also remove the delegate from the SDK. After calling this method no results from the operations performed from the SDK will be received, until a new delegate is set:

postPurchaseSDK.removeEventListener()

After creating an instance of the SDK, you need to initialize it with the following parameters. This is a mandatory step; you must wait for its result before doing any other operation.

postPurchaseSDK.initialize(
            locale: “en-SE”,
            purchaseCountry: ”SE”,
            design: “design”
)

If the result of initialize operation is successful, the "onInitialized" method in your delegate will be invoked. Otherwise, you will receive the error in the "onError" method. To know more about the errors, please refer to handling errors section.

After receiving the initialized successful callback, the next step is to authorize the user with Klarna. To fetch a user's orders list, you need a valid OAuth 2.0 access token. If you have never received this token for a user before, you need to trigger an OAuth flow in which the user will consent to the information sharing. 

The consent is market-specific and is based on the credentials you use when triggering the OAuth flow. If you want data for different markets, a separate consent flow needs to be triggered.

To use the authorize method in the SDK, a PostPurchaseAuthRequest object needs to be passed to the function, this object encapsulates the following parameters:

postPurchaseSDK.authorizationRequest(
           clientId = “497043bl6of4306lh54kgg54dslt39rg”,
           scope = “read:consumer_order”,
           redirectUri = “http://auth.example.com/callback”,
           locale = “en-SE”,
           state = “myState”,
           loginHint = “myuser@example.com”,
           responseType = “code”
        )

If the authorization flow (user consent) is successfully started, which means the user is presented with the Klarna consent page in the mobile web browser or inside the Klarna App (if it is installed), the "onAuthorizeRequested" method in your delegate will be invoked.

Important Note: The "onAuthorizeRequested" does not mean the consent flow is finished or successful. You will know the result of the flow in your redirectUri parameter.

If for any reason, SDK fails to start the consent flow in the first place, you will receive the error in the "onError" method. To know more about the errors, please refer to handling errors section.

After the flow is finished and has been redirected to the redirectUri, you will have to exchange the returned authorization code for an access and refresh token.

A successful consent flow will redirect to redirectUri with a “code”  URL parameter:  

http://auth.example.com/callback?code=0f25f67b4dahktj7782464gk0161e5beb14462e1

A rejected or canceled consent flow will redirect to redirectUri with an “error” URL parameter:

http://auth.example.com/callback?error=access_denied

You can use the authorization code you retrieved in the previous step to read the user's orders.

In a nutshell:

1. You need to exchange the authorization code with access token and refresh token
2. Use the access token to read the user's orders

Please contact your Klarna delivery manager for more information on how to accomplish this step.

Once you have user orders, you can present them in your application. Each order item contains a list of available operations (each with a unique token) so you can show them to the user in the order detail overview section and let the user initiate a Post Purchase operation using the SDK. When you call the "renderOperation" method, the SDK will render the relevant UI as a modal window in your application.

postPurchaseSDK.renderOperation(
           operationToken: ”s0u035ijoifkjg0j0ej0ierhj0”,
           locale: “en-SE”,
           redirectUri: “my-app://klarna-post-purchase”
)

After calling this method, you can show a loading indicator to the user while the Klarna UI modal is being created and presented. You should dismiss the loading when you get the result back in "onRenderedOperation" method in your delegate.

Possible result values in the callback method are found in the "KlarnaPostPurchaseRenderResult" enum and are as follows:

If the SDK fails to render the operation, you will receive the error in the "onError" method. To know more about the errors, please refer to handling errors section.

In case of any issues or errors while using the Post Purchase SDK functions, you will receive an error object of type "KlarnaPostPurchaseError" in the "onError" method of your delegate with the following attributes:

These are the predefined names for errors during the Post Purchase flow. These names are available as static variables inside "KlarnaPostPurchaseError" class.

Possible (but not limited to) “status” values in the error object for renderOperation method: