iOS Version 1.0+

Overview

To simplify your application logic and integration with the Knot iOS SDK, Version 1.0 includes a number of breaking changes that may affect the way your integration works or behaves. The new version includes a number of significant improvements:

Enhanced speed and stability in loading merchant flows.
More streamlined initialization of the SDK.
Simplified event handling, more informative event messaging, and uniform naming conventions for easier debugging.
Improved maintainability and foundations for new feature compatibility.

Breaking Changes

Configuring and opening the Knot SDK has changed significantly in iOS Version 1.0 and requires some refactoring in order to initialize the SDK with a session. Errors are now encapsulated in a KnotError object which provides an enumerated value to debug with.

Session Initialization

Changes

Knot.createCardSwitcherSession and Knot.createTransactionsLinkSession are replaced with a more flexible KnotConfiguration.
The new interface allows configuration of additional properties such as useCategories, useSearch, and merchantIds.
The open action now requires a KnotConfiguration and an optional KnotEventDelegate which is now Knot.open(configuration:delegate:).

Before

let session = CardOnFileSwitcherSession(sessionId: "SESSION_ID", clientId: "CLIENT_ID", environment: .sandbox)

session.entryPoint = "Onboarding" // Optionally, set an entry point.
session.merchantIds = [44] // Optionally, a specific merchant Id

Knot.open(session: session)

#import "CardOnFileSwitcherSession.h"
#import "Knot.h"

// ...

CardOnFileSwitcherSession *session = [[CardOnFileSwitcherSession alloc]
    initWithSessionId:@"SESSION_ID"
              clientId:@"CLIENT_ID"
           environment:CardOnFileSwitcherEnvironmentSandbox];

session.entryPoint = @"Onboarding"; // Optionally, set an entry point.
session.merchantIds = @[@44];       // Optionally, a specific merchant ID

[Knot openWithSession:session];

After

let configuration = KnotConfiguration(
    sessionId: "SESSION_ID",
    clientId: "CLIENT_ID",
    environment: .development,
    entryPoint: nil,
    product: .card_switcher,
    useCategories: true,
    useSearch: false,
    merchantIds: nil
)

Knot.open(configuration: configuration, delegate: self)

KnotConfiguration *configuration = [[KnotConfiguration alloc] 
    initWithSessionId:@"SESSION_ID"
              clientId:@"CLIENT_ID"
           environment:KnotEnvironmentDevelopment
            entryPoint:nil
               product:KnotProductCardSwitcher
         useCategories:YES
             useSearch:NO
           merchantIds:nil];

[Knot openWithConfiguration:configuration delegate:self];

Event Handling

Changes

Event handling is now managed through KnotEventDelegate instead of closures.
Events like onSuccess, onError, and onExit are now explicit methods inside a delegate.
The onEvent method introduces the KnotEvent object to better handle Knot emitted events.
The KnotError type provides improved error descriptions.
The sendCard parameter is deprecated and its functionality incorporated into the metaData dictionary within KnotEvent when KnotEvent.event equals AUTHENTICATED.

Before

session.onSuccess = { merchant in
    print("Successfully updated card for \(merchant)")
}

session.onError = { errorCode, errorMessage in
    print("Error: \(errorCode) - \(errorMessage)")
}

session.onExit = {
    print("User exited the SDK")
}

session.onEvent = { event, merchant, taskId, sendCard in
    print("event code: \(event), merchant: \(merchant), taskId: \(taskId), sendCard: \(sendCard)")
}

session.onSuccess = ^(Merchant *merchant) {
    NSLog(@"Successfully updated card for %@", merchant);
};

session.onError = ^(NSInteger errorCode, NSString *errorMessage) {
    NSLog(@"Error: %ld - %@", (long)errorCode, errorMessage);
};

session.onExit = ^{
    NSLog(@"User exited the SDK");
};

session.onEvent = ^(NSInteger event, Merchant *merchant, NSString *taskId, BOOL sendCard) {
    NSLog(@"event code: %ld, merchant: %@, taskId: %@, sendCard: %d",
          (long)event, merchant, taskId, sendCard);
};

After

class MyViewController: UIViewController, KnotEventDelegate {
    func onSuccess(merchant: String) {
        print("Successfully updated card for \(merchant)")
    }

    func onError(error: KnotError) {
        print("Error: \(error.errorDescription)")
    }

    func onEvent(event: KnotEvent) {
        print("Event: \(event.event)")
    }

    func onExit() {
        print("User exited the SDK")
    }
}

// MyViewController.m
#import "MyViewController.h"

@interface MyViewController : UIViewController <KnotEventDelegate>
@end

// MyViewController.h
@implementation MyViewController

- (void)onSuccessWithMerchant:(NSString *)merchant {
    NSLog(@"Successfully updated card for %@", merchant);
}

- (void)onErrorWithError:(KnotError *)error {
    // Assuming `KnotError` has an `errorDescription` property
    NSLog(@"Error: %@", error.errorDescription);
}

- (void)onEventWithEvent:(KnotEvent *)event {
    // Assuming `KnotEvent` has an `event` property or method
    NSLog(@"Event: %@", event.event);
}

- (void)onExit {
    NSLog(@"User exited the SDK");
}

@end 

SendCard

Most apps do not use the explicit sendCard method, as it is rarely applicable to the integration with the Knot SDK.

The sendCard parameter has been deprecated and its functionality is incorporated into the metaData dictionary within KnotEvent when the KnotEvent.event equals AUTHENTICATED. This change enhances flexibility by allowing additional contextual data to be included in events without requiring separate parameters. Previously, sendCard was accessed as a standalone value, but now developers can retrieve it from the metaData dictionary in the event callback. This approach ensures better extensibility and consistency across different event types. To access the sendCard value, simply extract it from the event’s metaData dictionary.

class MyViewController: UIViewController, KnotEventDelegate {
    func onSuccess(merchant: String) {
        print("Successfully updated card for \(merchant)")
    }

    func onError(error: KnotError) {
        print("Error: \(error.errorDescription)")
    }

    func onEvent(event: KnotEvent) {
        if event.event == "AUTHENTICATED" {
           print("Event.AUTHENTICATED sendCard: \(event.metaData["sendCard"] as? Bool)")
        }
    }

    func onExit() {
        print("User exited the SDK")
    }
}}

// MyViewController.h
@interface MyViewController : UIViewController <KnotEventDelegate>
@end

// MyViewController.m

#import "MyViewController.h"

@implementation MyViewController

- (void)onSuccessWithMerchant:(NSString *)merchant {
    NSLog(@"Successfully updated card for %@", merchant);
}

- (void)onErrorWithError:(KnotError *)error {
    // Assuming KnotError has a property named errorDescription
    NSLog(@"Error: %@", error.errorDescription);
}

- (void)onEventWithEvent:(KnotEvent *)event {
    // Assuming KnotEvent has an 'event' property (NSString *) and 'metaData' (NSDictionary *)
    if ([event.event isEqualToString:@"AUTHENTICATED"]) {
        // Safely extract the "sendCard" value from event.metaData
        NSNumber *sendCardNumber = event.metaData[@"sendCard"];
        BOOL sendCard = [sendCardNumber boolValue];

        NSLog(@"Event.AUTHENTICATED sendCard: %d", sendCard);
    }
}

- (void)onExit {
    NSLog(@"User exited the SDK");
}

@end

Event Names The SDK now maps raw event names to standardized event names for easier handling.

Event Name Prior to 1.0	1.0 Event Name
refresh session request	REFRESH_SESSION_REQUEST
merchant clicked	MERCHANT_CLICKED
login started	LOGIN_STARTED
authenticated	AUTHENTICATED
otp required	OTP_REQUIRED
security questions required	SECURITY_QUESTIONS_REQUIRED
approval required	APPROVAL_REQUIRED

Error Handling

Error handling has been improved with more structured and meaningful error messages. Changes

Errors are now encapsulated in the KnotError enum.
Each error has a human-readable description (errorDescription) and a unique error code (errorCode).
Improved clarity and consistency across error messages.

Before

session.onError = { errorCode, errorMessage in
    print("Error: \(errorCode) - \(errorMessage)")
}

session.onError = ^(NSInteger errorCode, NSString *errorMessage) {
    NSLog(@"Error: %ld - %@", (long)errorCode, errorMessage);
};

After

func onError(error: KnotError) {
    switch error {
    case .invalidSession:
        print("Error: Session is invalid. Please check your session ID.")
    case .expiredSession:
        print("Error: Session has expired. Please start a new session.")
    case .invalidClientId:
        print("Error: Invalid client ID. Ensure your credentials are correct.")
    case .internalError:
        print("Error: An internal error occurred. Try again later.")
    }
}

- (void)onErrorWithError:(KnotError)error {
    switch (error) {
        case KnotErrorInvalidSession:
            NSLog(@"Error: Session is invalid. Please check your session ID.");
            break;
        case KnotErrorExpiredSession:
            NSLog(@"Error: Session has expired. Please start a new session.");
            break;
        case KnotErrorInvalidClientId:
            NSLog(@"Error: Invalid client ID. Ensure your credentials are correct.");
            break;
        case KnotErrorInternalError:
            NSLog(@"Error: An internal error occurred. Try again later.");
            break;
    }
    
    // If you also need the string description or error code:
    NSString *description = KnotErrorDescription(error);
    NSString *code = KnotErrorCode(error);
    NSLog(@"Additional info => Description: %@, Code: %@", description, code);
}

Error Types The Knot SDK provides predefined error cases for you to handle based on your own needs.

Error Case	Description
.invalidSession	The session is invalid.
.expiredSession	The session has expired.
.invalidClientId	The client ID is invalid.
.internalError	An internal error occurred.

Closing the SDK

Most apps do not use the explicit close method, as it is infrequently applicable to the integration with the Knot SDK.

Changes

Closing the SDK is now statically accessed via Knot.close() as opposed to being bound to the session object.

Before

session.close()

[session close];

After

Knot.close()

[Knot close];

General

SDK

CardSwitcher

SubscriptionManager

TransactionLink

Detect

Vaulting

Shopping

Merchant Account Linking

iOS Version 1.0+

Overview

Breaking Changes

Session Initialization

Event Handling

Error Handling

Closing the SDK

​Overview

​Breaking Changes

​Session Initialization

​Event Handling

​Error Handling

​Closing the SDK

Overview

Breaking Changes

Session Initialization

Event Handling

Error Handling

Closing the SDK