iOS: Swift: MobilePaymentsSDK: Payments screen would not get presented for card reader swipe

Questions
,
4

Common Reasons for Payment Screen Not Appearing

  1. SDK Initialization First, verify the SDK is properly initialized. Add this before calling makeSquareTransaction:
// Add at app startup or before payments
func initializeSDK() {
    do {
        try MobilePaymentsSDK.shared.initialize(applicationLaunchOptions: nil)
        print("Square SDK initialized successfully")
    } catch {
        print("Failed to initialize Square SDK: \(error)")
    }
}
  1. Delegate Implementation Ensure your view controller properly implements PaymentManagerDelegate:
class YourViewController: UIViewController, PaymentManagerDelegate {
    // Required delegate methods
    func paymentManager(_ paymentManager: PaymentManager, didCompletePayment result: PaymentResult) {
        // Handle successful payment
    }
    
    func paymentManager(_ paymentManager: PaymentManager, didFailPayment error: Error) {
        // Handle payment failure
    }
    
    func paymentManagerDidCancel(_ paymentManager: PaymentManager) {
        // Handle payment cancellation
    }
}
  1. Modified Payment Parameters Here’s the complete makePaymentParameters function with all required fields:
func makePaymentParameters(amountMoney: Money) -> PaymentParameters {
    return PaymentParameters(
        idempotencyKey: UUID().uuidString,
        amountMoney: amountMoney,
        // Add these required parameters
        autocomplete: false,
        locationId: "YOUR_LOCATION_ID",
        customerId: nil,  // Optional
        notes: notes,     // Optional
        statementDescription: nil,  // Optional
        metadata: nil     // Optional
    )
}
  1. Updated Transaction Method Here’s the corrected makeSquareTransaction method with error handling:
func makeSquareTransaction(
    centsAmount: Int,
    notes: String,
    from viewController: UIViewController
) {
    // Verify SDK initialization
    guard MobilePaymentsSDK.shared.isInitialized else {
        print("Square SDK not initialized")
        return
    }
    
    // Verify delegate
    guard let vc = viewController as? PaymentManagerDelegate else {
        print("PaymentManagerDelegate is required")
        return
    }
    
    // Create payment parameters
    let amountMoney = Money(amount: UInt(centsAmount), currency: .USD)
    let paymentParams = makePaymentParameters(amountMoney: amountMoney)
    
    // Create prompt parameters
    let paymentPromptParameters = PromptParameters(
        mode: .default,
        additionalMethods: .all
    )
    
    // Start payment with completion handler
    DispatchQueue.main.async {
        MobilePaymentsSDK.shared.paymentManager.startPayment(
            paymentParams,
            promptParameters: paymentPromptParameters,
            from: viewController,
            delegate: vc
        ) { result in
            switch result {
            case .success:
                print("Payment screen presented successfully")
            case .failure(let error):
                print("Failed to present payment screen: \(error)")
            }
        }
    }
}

Implementation Checklist

  1. Verify Info.plist Settings
<key>NSCameraUsageDescription</key>
<string>Required for card scanning</string>
<key>NSMicrophoneUsageDescription</key>
<string>Required for tap to pay</string>
<key>NSNFCReaderUsageDescription</key>
<string>Required for tap to pay</string>
  1. Add Required Capabilities In Xcode:
  • Enable “Near Field Communication Tag Reading” capability
  • Enable “Payment Processing” capability
  1. Usage Example
class YourViewController: UIViewController, PaymentManagerDelegate {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        initializeSDK()
    }
    
    @IBAction func onPayButtonTapped(_ sender: Any) {
        makeSquareTransaction(
            centsAmount: 1000, // $10.00
            notes: "Test payment",
            from: self
        )
    }
    
    // Delegate methods implementation
    func paymentManager(_ paymentManager: PaymentManager, didCompletePayment result: PaymentResult) {
        print("Payment completed: \(result)")
    }
    
    func paymentManager(_ paymentManager: PaymentManager, didFailPayment error: Error) {
        print("Payment failed: \(error)")
    }
    
    func paymentManagerDidCancel(_ paymentManager: PaymentManager) {
        print("Payment cancelled")
    }
}

Debugging Steps

  1. Add logging to track the flow:
print("SDK Initialized: \(MobilePaymentsSDK.shared.isInitialized)")
print("Payment Parameters: \(paymentParams)")
print("View Controller: \(viewController)")
  1. Check for any console errors or warnings
  2. Verify you’re calling this on the main thread