Initializing the SDK

To use the SDK’s methods and classes, your application must call the SDK’s initialise method to initialize the MobileCredentialHolder class.

func initialise(
    instanceID: String = defaultInstanceID,
    userAuthRequiredOnInitialise: Bool = true,
    loggerConfiguration: LoggerConfiguration = LoggerConfiguration()
) throws

Initialize a specific instance

You can initialize this singleton class with one instanceId at a time:

    init() {
        do {
            mobileCredentialHolder = MobileCredentialHolder.shared
            try mobileCredentialHolder.initialise(instanceID: "1234")
        } catch {
            print(error)
        }
    }

Once initialized, all subsequent method calls in this class will only return results specific to this instanceId.

If no instanceId is provided, the default instance is initialized (00000000-0000-0000-0000-000000000000).

Configure authentication requirements

You can configure the method to require user authentication (biometric or passcode) upon initialization using the optional userAuthRequiredOnInitialise parameter:

    init() {
        do {
            mobileCredentialHolder = MobileCredentialHolder.shared
            try mobileCredentialHolder.initialise(userAuthRequiredOnInitialise: true)
        } catch {
            print(error)
        }
    }

UX Considerations and best practices

Setting userAuthRequiredOnInitialise to true would require granting bluetooth permissions to your wallet application. To enable this, you must add the NSBluetoothAlwaysUsageDescription attribute to the application’s info.plist file.

Configure logger behavior

You can configure the SDK’s logger behavior using the optional loggerConfiguration parameter:

    init() {
        do {
            let loggerConfiguration = LoggerConfiguration(
                logLevel: .Debug,
                callbackLogLevel: .Debug) { event in
                    print(
                        "Perform any custom action with the log event: \(event.message)"
                    )
                }
 
            mobileCredentialHolder = MobileCredentialHolder.shared
            try mobileCredentialHolder
                .initialise(
                    loggerConfiguration: loggerConfiguration
                )
        } catch {
            print(error)
        }
    }

• logLevel : Determines which events are written to log files:
• callbackLogLevel : Determines which events invoke the callback function:
• callback : Defines the function to call when events defined by callbackLogLevel occur.

Logging levels

These levels apply to both the logLevel and callbackLogLevel parameters (corresponding raw value in shown in parenthesis):

• Off (0).
• Error (1).
• Warning (2).
• Info (3).
• Debug (4).
• Verbose (5).