future_payments_mobile.md

Future Payments Mobile Integration

This section will show how to obtain a user's authorized consent for future payments using their PayPal account.

If you haven't already, see the README for an initial overview and instructions for adding the SDK to your project.

Overview

Your app will use the mobile SDK to obtain two pieces of information at different times.

First, you must obtain customer consent to take payments from their PayPal account. How this works:

• The PayPal iOS SDK...
  1. Presents UI for your user to authenticate using their PayPal account.
  2. Asks your user to consent to OAuth access token scope to use PayPal for future payments.
  3. Returns an OAuth2 authorization code to your app.
• Your app...
  1. Receives an OAuth2 authorization code from the SDK.
  2. Sends the authorization code to your server, which then exchanges the code for OAuth2 access and refresh tokens.

Later, when initiating a pre-consented payment, you must obtain an Application Correlation ID. How this works:

• The PayPal iOS SDK...
  • Provides an Application Correlation ID.
• Your app...
  • Sends the Correlation ID and transaction information to your server.
  • Your server then uses its OAuth2 tokens, Application Correlation ID, and transaction info to create a payment.

Obtain Customer Consent

1. Initialize the SDK and provide your Client IDs. A typical place to do this is in your app delegate's didFinishLaunchingWithOptions: method.

   - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
   {
     // ...
     [PayPalMobile initializeWithClientIdsForEnvironments:@{PayPalEnvironmentProduction : @"YOUR_CLIENT_ID_FOR_PRODUCTION",
                                                            PayPalEnvironmentSandbox : @"YOUR_CLIENT_ID_FOR_SANDBOX"}];
     // ...
     return YES;
   }

   Note: if you have not yet obtained a Client ID for the Live environment, you may omit the PayPalEnvironmentProduction entry.

2. Create a class (such as a subclass of UIViewController) that conforms to PayPalFuturePaymentDelegate.

   // SomeViewController.h
   #import "PayPalMobile.h"
   
   @interface SomeViewController : UIViewController<PayPalFuturePaymentDelegate>
   // ...
   @end

3. Create a PayPalConfiguration object. This object allows you to configure various aspects of the SDK.

   // SomeViewController.m
   
   @interface SomeViewController ()
   // ...
   @property (nonatomic, strong, readwrite) PayPalConfiguration *payPalConfiguration;
   // ...
   @end
   
   @implementation SomeViewController
   
   - (instancetype)initWithCoder:(NSCoder *)aDecoder {
     self = [super initWithCoder:aDecoder];
     if (self) {
       _payPalConfiguration = [[PayPalConfiguration alloc] init];
   
       // See PayPalConfiguration.h for details and default values.
   
       // Minimally, you will need to set three merchant information properties.
       // These should be the same values that you provided to PayPal when you registered your app.
       _payPalConfiguration.merchantName = @"Ultramagnetic Omega Supreme";
       _payPalConfiguration.merchantPrivacyPolicyURL = [NSURL URLWithString:@"https://www.omega.supreme.example/privacy"];
       _payPalConfiguration.merchantUserAgreementURL = [NSURL URLWithString:@"https://www.omega.supreme.example/user_agreement"];
   
     }
     return self;
   }

4. Establish environment, and preconnect to PayPal's servers.

   We recommend doing this when you first display the view controller from which your users might initiate payment. (Do not preconnect significantly earlier than that, as the connection has a limited lifetime.)

   // SomeViewController.m
   
   - (void)viewWillAppear:(BOOL)animated {
     [super viewWillAppear:animated];
   
     // Start out working with the mock environment. When you are ready, switch to PayPalEnvironmentProduction.
     [PayPalMobile preconnectWithEnvironment:PayPalEnvironmentNoNetwork];
   }

5. Create and display a PayPalFuturePaymentViewController with configuration.

   // SomeViewController.m
   
   - (IBAction)obtainConsent {
   
     PayPalFuturePaymentViewController *fpViewController;
     fpViewController = [[PayPalFuturePaymentViewController alloc] initWithConfiguration:self.payPalConfiguration
                                                                                delegate:self];
   
     // Present the PayPalFuturePaymentViewController
     [self presentViewController:fpViewController animated:YES completion:nil];
   }

6. Implement the PayPalFuturePaymentDelegate delegate methods to receive either the authorization response on success, or notification that the user cancelled. Your implementation is responsible for dismissing the modal view controller.

   // SomeViewController.m
   
   #pragma mark - PayPalFuturePaymentDelegate methods
   
   - (void)payPalFuturePaymentDidCancel:(PayPalFuturePaymentViewController *)futurePaymentViewController {
     // User cancelled login. Dismiss the PayPalLoginViewController, breathe deeply.
     [self dismissViewControllerAnimated:YES completion:nil];
   }
   
   - (void)payPalFuturePaymentViewController:(PayPalFuturePaymentViewController *)futurePaymentViewController
                   didAuthorizeFuturePayment:(NSDictionary *)futurePaymentAuthorization {
     // The user has successfully logged into PayPal, and has consented to future payments.
   
     // Your code must now send the authorization response to your server.
     [self sendAuthorizationToServer:futurePaymentAuthorization];
   
     // Be sure to dismiss the PayPalLoginViewController.
     [self dismissViewControllerAnimated:YES completion:nil];
   }

7. Send the authorization response to your server in order to complete the process.

   // SomeViewController.m
   
   - (void)sendAuthorizationToServer:(NSDictionary *)authorization {
     // Send the entire authorization reponse
     NSData *consentJSONData = [NSJSONSerialization dataWithJSONObject:authorization
                                                               options:0
                                                                 error:nil];
   
     // (Your network code here!)
     //
     // Send the authorization response to your server, where it can exchange the authorization code
     // for OAuth access and refresh tokens.
     //
     // Your server must then store these tokens, so that your server code can execute payments
     // for this user in the future.
   }

Obtain an Application Correlation ID

When initiating a pre-consented payment (a "future payment") from a mobile device, your mobile application must obtain an Application Correlation ID from the Mobile SDK to pass to your server. Your server must include this Application Correlation ID in its payment request sent to PayPal.

PayPal uses this Application Correlation ID to verify that the payment is originating from a valid, user-consented device+application. This helps reduce fraud and decrease declines. PayPal does not provide any loss protection for transactions that do not correctly supply an Application Correlation ID.

Do not cache or store this value.

Example:

- (IBAction)paymentButtonTapped:(UIButton *)sender {

    // Display activity indicator...

    NSString *correlationId = [PayPalMobile applicationCorrelationIDForEnvironment:PayPalEnvironmentProduction];

    // Send correlationId and transaction details to your server for processing with PayPal...
}

When your server makes its payment request to PayPal, it must include a Paypal-Application-Correlation-Id HTTP header with this Application Correlation ID value obtained from the SDK.

Next Steps

Read Future Payments Server-Side Integration to exchange the authorization code for OAuth2 tokens and create payments with an access token and a Correlation ID.