PayPal App Switch (Beta)

iOS v6

• Current Braintree SDKs
• Android v5
• iOS v6
• JavaScript v3
• Previous Versions
• Android v4
• iOS v5
• JavaScript v2

In this experience the SDK will attempt to switch to the PayPal App after calling tokenize if the PayPal App is installed and the user meets eligibility requirements. If the switch into the PayPal App cannot be completed, we will fall back to the ASWebAuthenticationSession experience.

Using a custom UI

You can optionally implement a custom button to start a PayPal flow.

Get the SDK

The PayPal App Switch is part of the BraintreePayPal module in the Braintree SDK. This module can be pulled into your app via all of the currently supported package managers.

Cocoapods

In your Podfile, add the dependency for the PayPal Mobile Checkout module:

pod 'Braintree/PayPal'

Swift Package Manager

Include the BraintreeCore, BraintreePayPal, and PayPalDataCollector frameworks.

Carthage

Include the BraintreeCore, BraintreePayPal and PayPalDataCollector frameworks.

Allowlist PayPal URL Scheme

You must add the following to the queries schemes allowlist in your app's info.plist:

<key>LSApplicationQueriesSchemes</key>
<array>
  <string>paypal-app-switch-checkout</string>
</array>

Set Up Universal Links

In order to use the PayPal App Switch flow your application must be set up for Universal Links. You will need to use a custom path dedicated to Braintree app switch returns. This URL must also be added to your app association file with wildcards allowed to ensure we receive the expected data on return.

{
  "applinks": {
    "details": [
      {
        "appID": "com.your-app-id",
        "paths": [
          "/braintree-payments/*"
        ]
      }
    ]
  }
}

Register Universal Link in Control Panel

Before using this feature, you must register your Universal Link domain in the Braintree Control Panel:

1. Log into your Control Panel (e.g. Sandbox, or Production).
2. Click on the gear icon in the top right corner. A drop-down menu will open.
3. Click Processing from the drop-down menu.
4. Scroll to the Payment Methods section.
5. Next to PayPal, click the Options link. This will take you to your linked PayPal Account(s) page.
6. Click the View Domain Names button. This will take you to the PayPal Domain Names page.
   • Note: If you have a single PayPal account, it will be at the bottom of the page. If you have multiple PayPal accounts, it will be at the top right of the page.
7. Click the + Add link on the top right of the page or scroll to the Specify Your Domain Names section.
8. In the text box enter your list of domain names separated by commas.
   • Note: The value you enter must match your fully qualified domain name exactly – including the "www." if applicable.
9. Click the Add Domain Names button.
10. If the domain registration was successful for all the domain names listed in the text box, a banner will display the text "Successfully added domains". The registered domain names will be displayed in alphabetical order under the + Add button.
11. If the registration was not successful for any of the domain names listed in the text box, a banner will display a list of domain names that failed qualified domain name validation along with their reasons for rejection. Any domain names that were successfully registered will be displayed in alphabetical order under the + Add button.
    • Note: You can re-enter the rejected domain names in the text area with the corrections applied.

Set Universal Link in SDK

You will need to use the following BTPayPalClientinit to set your Universal Link:

let apiClient = BTAPIClient(authorization: <#CLIENT_AUTHORIZATION#>)
let payPalClient = BTPayPalClient(
  apiClient: apiClient, // required
  universalLink: URL(string: "https://my-universal-link.com/braintree-payments")! // required
)

Handle App Context Switching

Then pass the URL to Braintree for completion of the flow.

If you’re using SwiftUI, you must add the onOpenURL(perform:) modifier to your ContentView, and then call BTAppContextSwitcher's handleOpen(_:) method.

.onOpenURL { url in
  BTAppContextSwitcher.sharedInstance.handleOpen(url)
}

If you're using UISceneDelegate (introduced in iOS 13), call the handleOpen(_:) method from within the scene(_:continue:) scene delegate method.

func scene(_ scene: UIScene, continue userActivity: NSUserActivity) {
  if let returnURL = userActivity.webpageURL, returnURL.path.contains("/my-dedicated-braintree-path") {
    BTAppContextSwitcher.sharedInstance.handleOpen(returnURL)
  }
}

Otherwise, if you aren't using UISceneDelegate, call the handleOpen(_:) method method from within the application(_:continue:restorationHandler:) app delegate method.

func application(_ application: UIApplication, continue userActivity: NSUserActivity, restorationHandler: @escaping ([UIUserActivityRestoring]?) -> Void) -> Bool {
  if let returnURL = userActivity.webpageURL, returnURL.path.contains("/my-dedicated-braintree-path") {
    BTAppContextSwitcher.sharedInstance.handleOpen(returnURL)
  }
}

Invoking the PayPal App Switch Flow

Opt In to The App Switch Flow

Construct a BTPayPalVaultRequest or a BTPayPalCheckoutRequest with enablePayPalAppSwitch set to true and a userAuthenticationEmail included. Use this with your BTPayPalClient from above to call BTPayPalClient.tokenize(_:completion:) to launch the PayPal App Switch flow.

An example integration might look like this:

import UIKit
import BraintreePayPal

class MyViewController: UIViewController {
  var apiClient: BTAPIClient!
  var payPalClient: BTPayPalClient!

  override func viewDidLoad() {
    super.viewDidLoad()
    apiClient = BTAPIClient(authorization: <#CLIENT_AUTHORIZATION#>)
    payPalClient = BTPayPalClient(
      apiClient: apiClient, 
      universalLink: universalLink: URL(string: "https://my-universal-link.com/braintree-payments")! // required for this flow
    )
  }

  private func payPalButtonTapped() {
    // vault flows
    let request = BTPayPalVaultRequest(
      userAuthenticationEmail: "sally@gmail.com",
      enablePayPalAppSwitch: true
    )

    // one time checkout flows
    let request = BTPayPalCheckoutRequest(
      amount: amount
      userAuthenticationEmail: "sally@gmail.com",
      enablePayPalAppSwitch: true
    )
    
    // userAuthenticationEmail and enablePayPalAppSwitch are required for this flow
    // Configure other values on 'request' as needed.

    payPalClient.tokenize(request) { payPalNonce, error in
      if let payPalNonce { 
        // send payPalNonce.nonce to server 
      } else { 
        // handle error
      }
    }
  }
}

Testing

In order to test this flow in Sandbox, you will first need access to the TestFlight PayPal Sandbox app. Additionally, you are required to remove the Production PayPal app from your device to complete the App Switch flow successfully in Sandbox. Please reach out to app-switch-onboarding@paypal.com for access to the TestFlight PayPal Sandbox app.