iOS SDK - Technical Guide


This document helps developers to set up and integrate Cardknox Payments SDK into Objective C and Swift projects. The document contains steps for framework integration, required settings setup and import of SDK headers.

Technical Overview

  • The SDK is distributed as a .framework

  • .framework contains the CardknoxPaymentsSDK binary and ObjectiveC .h headers describing the SDK API

  • The CardknoxPaymentsSDK does not contain bitcode and cannot be integrated with applications that require bitcode

  • .framework only supports arm64 64-bit architecture for device builds. Simulator targets are not supported.

  • SDK minimum deployment target is 14.0

Framework File Integration

  1. Download the zip file with CardknoxPaymentsSDK.framework. Links for downloading framework files can find in iOS SDK - Get Started section.

  2. Extract CardknoxPaymentsSDK.framework from downloaded .zip file.

Required Settings Setup

Disabling Bitcode

The Cardknox SDK doesn’t support bitcode. To disable Bitcode follow these steps:

  1. Click on your application target. Choose Build Settings > All

Info.plist merge

  1. The CardknoxPaymentsSDK framework contains an Info.plist file which contains various key/value pairs that are required by the framework, for example, it defines a NSBluetoothAlwaysUsageDescription key with a value similar to “Bluetooth is required to find, connect to and transfer data between a card reader and the app"

  2. The application that is using the CardknoxPaymentsSDK framework also defines an Info.plist file with its own key/value pairs

  3. The goal is to merge the framework Info.plist file with the application Info.plist in order to avoid runtime errors in the CardknoxPaymentsSDK framework code due to missing key/values. XCode doesn't perform any merges automatically.

  4. Note that if there are identical keys present in the application Info.plist and in the framework Info.plist files, such as the NSBluetoothAlwaysUsageDescription key; the value defined in the application Info.plist for that key will have priority during the merge; making it easy to override values in the framework Info.plist

  5. To merge the two files, define a Run Script step in the XCode application Target's Build Phases section and run the PlistBuddy tool, as following:

    • Delete the Type a script... contents of the input box and add the following command

CardknoxPaymentsSDK headers import

This section shows how to use the CardknoxPaymentsSDK in Objective C and Swift code. For Objective C it’s sufficient to reference the main SDK header. For Swift, an umbrella header is required to wrap the main SDK header into a Swift compatible format.

Objective C import

For Objective C applications - reference the CardknoxPaymentsSDK main header file in your code with #import "CardknoxPaymentsSDK/CardknoxPaymentsSDK.h"

Swift import

For Swift applications - an umbrella header needs to be created and referenced by your application Target in order to properly embed the framework into your app. To create the umbrella header, follow the steps:

  1. Clear all text in the header file

  2. Navigate to your target’s Build Settings > All

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