iOS

The Viva Wallet Card Terminal App for iOS can receive requests for initiating transactions from third-party apps installed on the same iOS mobile device. Communication with the Card Terminal App is done through the use of URL schemes and by implementing UIApplicationDelegate’s instance method application(_:open:options:) on the AppDelegate file of the client’s app project. The client app should create an URL scheme using specific parameters that will initiate the Card Terminal App’s pay activity. When the Card Terminal App’s pay activity finishes it returns the transaction result to the caller app.

A sample app is also available for download from our public GitHub account. It demonstrates the inter-app communication ability and contains all necessary info.

Messages

The client app must implement a mechanism to send messages using iOS intents and URI calls and to receive the result in a custom URI callback. Overall the following messages are available:

• Sale request originating from the client app to initiate a request for a new Sale transaction.
• Sale response originating from the Card terminal app to return the result of a Sale transaction.
• Cancel request originating from the client app to initiate a request for a Cancel transaction.
• Cancel response originating from the Card terminal app to return the result of a Cancel transaction.

Callback activity

The card terminal app will deliver the URL to your app by calling your app delegate’s application(_:open:options:) method. The following code should be added to the method in order to parse the contents of the URL and take the appropriate actions. To ensure the URL is parsed correctly, use NSURLComponents APIs to extract the components.

func application(_ app: UIApplication, open url: URL, options: [UIApplication.OpenURLOptionsKey : Any] = [:]) -> Bool {

        guard let components = NSURLComponents(url: url, resolvingAgainstBaseURL: true),
            let path = components.path,
            let params = components.queryItems else {
                print("Invalid URL or path missing")
                return false
        }
        print("Path: \(path)\nComponents: \(params)")

        //MARK: - Do any additional actions after parsing the data
        return true
 }

Sale request 

For a typical sale request the client app must provide the following information:

Using the information above, our custom URI should be created like this.

static let schemeURL = "vivapayclient://pay/v1" // The Viva's custom URL scheme, the host and the version.
        static let callback = "?callback=interapp-callback" // The URI callback that will handle the result.
        static let merchantKey = "&merchantKey=SG23323424EXS3" // The merchant's key.
        static let clientAppID = "&appId=com.vivawallet.InterAppDemo" // The client app id.
        static let saleAction =  "&action=sale" // Sale transaction


    func createSaleRequest(amount: Decimal, tipAmount: Decimal?, numberOfInstallments: Int?, clientTransactionId: String?) -> String {

        // construct sale action url
        var saleActionURL = schemeURL + callback + merchantKey + clientAppID + saleAction

        saleActionURL += "&amount=\(((amount * 100) as NSDecimalNumber).intValue)" // The amount in cents without any decimal digits.

        if let tip = tipAmount {
            saleActionURL += "&tipAmount=\(((tip * 100) as NSDecimalNumber).intValue)" // The tip amount in cents without any decimal digits.
        }

        // append clientTransactionId parameter (if any)
        if let transactionId = clientTransactionId {
            saleActionURL += "&clientTransactionId=\(transactionId)"
        }

        // append number of installments parameter (if any)
        if let preferredInstallments = numberOfInstallments, preferredInstallments > 1 {
            saleActionURL += "&withInstallments=true" // enable installments parameter
            saleActionURL += "&preferredInstallments=\(preferredInstallments)"
        }
        else {
            saleActionURL += "&withInstallments=false" // no installments parameter (should be used)
        }

        return saleActionURL
    }

    func performInterAppRequest(request: String){

        guard let url = URL(string: request) else { return } // url with constructed parameters
        UIApplication.shared.open(url) { (result) in
            if result {
                // The URL was delivered successfully!
            }
        }
    }

    //USE LIKE THIS
       let saleRequestStringURL: String = createSaleRequest(amount: 12.00, tipAmount: 2.00, numberOfInstallments: nil, clientTransactionId: nil)
     performInterAppRequest(request: saleRequestStringURL)

Sale response

After executing a Sale transaction the card terminal app responds with a Sale Response result to indicate if the transaction has been approved or not.

The result is received as a URI in the callback activity.

The table below summarises the contents of an approved response.

A Sale response result for an approved transaction looks as follows:

mycallbackscheme://result?status=success&message=Transaction%20successful.&action=sale&clientTransactionId=12345678901234567890123456789012&amount=1200&tipAmount=200&verificationMethod=CHIP-PIN&rrn=123456833121&cardType=VISA&accountNumber=479275******9999&referenceNumber=833121&authorisationCode=690882&tid=16016684&orderCode=9256110059000200&installments=10&transactionDate=2019-09-13T12:14:19.8703452+03:00&transactionId=a78e045c-49c3-4743-9071-f1e0ed71810c

It is expected that certain transactions will fail for various reasons. A Sale response result for a failed transaction looks as follows:

mycallbackscheme://result?status=failed&message=Transaction%20declined%20by%20host.&action=sale&clientTransactionId=12345678901234567890123456789012&amount=1200&tipAmount=200&verificationMethod=CHIP-PIN&rrn=123456833121&cardType=VISA& accountNumber=479275******9999&referenceNumber=&authorisationCode=&tid=16016684&orderCode=9256110059000200&transactionDate=2019-09-13T12:14:19.8703452+03:00

The structure of the message is the same as in the case of an approved transaction. Fields such as referenceNumber and authorisationCode may not have values since there is no STAN code available, nor an authorisation code.

Cancel request 

For a typical cancel request the client app must provide the following information:

The above information elements must create a URI call, i.e.

let cancelAction = "&action=cancel"

    func createCancelRequest(reference: String?) -> String {

        // construct sale action url
        var cancelActionURL = schemeURL + callback + merchantKey + clientAppID + cancelAction

        if let unwrappedReference = reference, unwrappedReference != "" {
            cancelActionURL += "&referenceNumber=\(unwrappedReference)" // transaction reference number
        }

        return cancelActionURL
    }

    //USE LIKE THIS
    let canceRequestStringURL: String = createCancelRequest(reference: "60646")
    performInterAppRequest(request: canceRequestStringURL)

Cancel response

After executing a Cancel transaction the card terminal app responds with a Cancel response result to indicate if the transaction has been approved or not.

The result is received as a URI in the callback activity.

The table below summarises the contents of an approved response:

A Cancel response result for an approved transaction looks as follows:

mycallbackscheme://result?status=success&message=Transaction%20successful.&action=cancel&amount=1200 &cardType=VISA&accountNumber=479275******9999&tid=16016684&transactionDate=2019-09-13T12:14:19.8703452+03:00&transactionId=a78e045c-49c3-4743-9071-f1e0ed71810c

It is expected that certain transactions will fail for various reasons. A Cancel response result for a failed transaction looks as follows:

mycallbackscheme://result?status=success&message=Transaction%20successful.&action=cancel&amount=1200& cardType=VISA&accountNumber=479275******9999&tid=16016684&transactionDate=2019-09-13T12:14:19.8703452+03:00

The structure of the message is the same as in the case of an approved transaction.