5. Display the transaction context

Handle ContactlessPaymentSession.Event.transactionCompleted to show the payment status to the end user.

This event includes a TransactionContext that contains key details about the transaction.

Handle the completion event

In your ContactlessPaymentSession.eventStream loop, handle:

• .transactionCompleted(let transactionContext)

Use transactionContext to update your UI and trigger any follow-up actions.

TransactionContext fields

TransactionContext typically includes:

• aid: EMV application identifier (AID).

• amount: Transaction amount (formatted for display in your UI).

• rawAmount: Raw amount value as received from the terminal.

• currencyCode: ISO-4217 numeric currency code.

• transactionDate: Transaction date (YYMMDD, BCD-encoded).

• transactionType: Transaction type code (for example, purchase vs refund).

• digitalCardID: Digital card identifier used for the payment.

• scheme: Payment network (for example, Visa or Mastercard).

• isTransit: Indicates whether the transaction is a transit transaction.

• transactionID: Transaction identifier.

Refer to the following example code snippet for implementation instructions:

Format and display transaction context

func displayTransactionContext(_ context: TransactionContext) {
    // Set this to your locale.
    let locale = Locale(identifier: "en_US")

    // Map ISO-4217 numeric codes to alphabetic codes.
    // Expand this mapping based on your supported currencies.
    let iso4217NumToCode: [Int: String] = [
        978: "EUR",
        840: "USD"
    ]

    let currencyFormatter = NumberFormatter()
    currencyFormatter.locale = locale
    currencyFormatter.numberStyle = .currency

    if let currencyCode = iso4217NumToCode[context.currencyCode.bcdToInt()] {
        currencyFormatter.currencyCode = currencyCode
    }

    let rawDateFormatter = DateFormatter()
    rawDateFormatter.dateFormat = "yyMMdd"

    guard let transactionDate = rawDateFormatter.date(from: context.transactionDate.bcdToString()) else {
        // Fallback: skip date rendering if parsing fails.
        return
    }

    let displayDateFormatter = DateFormatter()
    displayDateFormatter.locale = locale
    displayDateFormatter.dateStyle = .medium

    let amountStr = currencyFormatter.string(from: context.amount as NSNumber) ?? "-"
    let dateStr = displayDateFormatter.string(from: transactionDate)

    let transactionTypeStr = context.transactionType.bcdToString()
    switch transactionTypeStr {
    case "00":
        // Purchase
        break
    case "20":
        // Refund / correction
        break
    default:
        // Unknown transaction type
        break
    }

    // Update your UI with amountStr, dateStr, scheme, isTransit, and transactionID.
}