How to call Swift from an Objective C project App Delegate?

This code is from a Swift project App delegate. It is used to help configure Stripe with a publishable key.

//Appdelegate.swift  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions:   [UIApplicationLaunchOptionsKey: Any]?) -> Bool   {  //The code helps configure Stripe with a publishable key.  STPPaymentConfiguration.shared().publishableKey = Constants.publishableKey  ...  }  

Two errors are displayed when building the app after adding the Swift line to the Objective C App Delegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions  {  STPPaymentConfiguration.shared().publishableKey = Constants.publishableKey  

Property 'shared' not found on object of type 'STPPaymentConfiguration'  Use of undeclared identifier 'Constants'  

This was a similar error in compiling before @objc was added to the demo Swift function, MockApiClient. Should it be added elsewhere? I've tried adding @objc to the enum as mentioned in the answer here to no avail yet.

//Constants.swift   //This is the file the original Swift app delegate accesses  import Foundation      enum Constants {    static let publishableKey = "pk_live_..."    static let baseURLString = "http://54.33.123.227:1234"    static let defaultCurrency = "usd"    static let defaultDescription = "Receipt" //change to describe actual app & charge    }  

Steps taken:

1. Opened the Objective C project and created a bridging header

2. Created a demo class in Swift while still in the Obj C project to make sure it can be used, in this case to print from an Objective C file when the view is loaded. Specifically derived from an NSObject. Adding the override to the initializer and using the @objc prefix.

   //  MockApiClient.swift  import Foundation  class MockApiClient: NSObject  {  override init()  {  print("Initializer called in Mock API client")  }  @objc func executeRequest()  {  print("The execute request has been called in the Mock API Client")  }  }    //ViewController.h  //Prints the Swift request written in the MockApiClient the the view loads    @implementation ViewController  - (void)viewDidLoad  {  [super viewDidLoad];  // Do any additional setup after loading the view, typically from a nib.  MockApiClient *client = [MockApiClient new];  [client executeRequest];  }  

3. Copied the #import "ViewController.h" import to the automatically generated project-Bridging-Header.h file to expose the Objective C in it to swift

4. Added the necessary Swift files to the Objective C project so that the Constants.publishablekey data from Constants.swift can be found

How can this Swift App delegate code be added to the App delegate of an Objective C project?

https://stackoverflow.com/questions/65854409/how-to-call-swift-from-an-objective-c-project-app-delegate January 23, 2021 at 08:10AM