Call swift code from objc code in objc project

The bridging header generated is empty by default.

Do you realize you posted this in the Objective-C forum rather than the Swift forum?

I would post 'call obj c code from swift code' in the swift forum. Being centered around objc, I eould suppose things working with objc would be best posted in obj c forum

Did you declare

MySwiftClass

@objc

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Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

Here are the steps i took after reading your last answer and the article on importing swift code into objective.

1. created a header file for swift fle
2. included @class className in it
3. included #import "AppName-Swift.h"
4. Compiler gave error saying swift language version needs to be set in build settings. rectified it.

No w I get unknown type name on trying to define a pointer to the swift class.

do i need to reference the class in swift from my objective c .m file or should i using objc code itself.

I’m honestly not sure how you managed to get into the state you’ve got into. It’s hard to debug such problems without having access to your project. As an alternative, I’ve included working instructions below. Please try repeating this at your end. That’ll help in one of two ways:

• If they don’t work, there’s something wonky in your environment.

• If they do work, you have a working example that you can compare against your main project.

Here’s what I did:

1. In Xcode 11.3, I created a new app from the macOS > App template. I named it MyApp, set the language to Objective-C, and the UI to Storyboard.

2. In the Project navigation on the left, I selected

   main.m

   and then chose File > New > File.

3. I selected the macOS > Swift template and named the file

   MySwiftClass.swift

   .

4. After saving the file, Xcode asked me whether I wanted to create a bridging header. I clicked Create Bridging Header. This isn’t necessary for this task, but you’ll likely need it later and it’s best to do it at this point.

5. I change

   MySwiftClass.swift

   to look like this:

   import Foundation
   
   
   @objc
   class MySwiftClass: NSObject {
   
   
   @objc
   func run() {
       print("MySwiftClass.run \(Date())")
   }
   }

   .

6. In the Project navigation on the left, I selected

   main.m

   again.

7. I added this line after the existing

   #import

   :

   #import "MyApp-Swift.h"

   .

8. Inside the

   @autoreleasepool

   I added this code:

   MySwiftClass * obj = [[MySwiftClass alloc] init];
   [obj run];

   .

9. I ran the app. It printed:

   MySwiftClass.run 2020-02-20 10:37:03 +0000

   .

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

Except for adding objc to the function call also (which i didnt make a call to yet), I did the same thing.

Now xcode is giving me a different error.

where I have written

MySwiftClass *ptr;
ptr = [[MySwiftClass allo]init];

I get errory saying no init found. here is my class...

//
//  StoreObserver.swift
//  Step Goals
//
//  Created by Neerav Kothari on 18/02/20.
//  Copyright © 2020 Neerav Kothari. All rights reserved.
//

import Foundation
import StoreKit

@objc class StoreObserver: NSObject, SKPaymentTransactionObserver {

    //Initialize the store observer.
    @objc override init() {
        super.init()
        //Other initialization here.
    }

    //Observe transaction updates.
    @objc func paymentQueue(_ queue: SKPaymentQueue,updatedTransactions transactions: [SKPaymentTransaction]) {
        //Handle transaction states here.
    }

}

This code is actually from a in-app purchase documentation which has a bug and it wont load the objc code.

Now what can I do so that it finds init.

I dont know swift.

You need a "c" in

ptr = [[MySwiftClass allo]init];

ptr = [[MySwiftClass alloc] init];

You should be able to find code that implements IAP written in Objective C.

It's alloc only. That was a type in the post.

I did the same thing.

Did you actually run through my steps?

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—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

Did you actually run through my steps?

Sorry, that wasn’t clear. What I should’ve said was…

Did you run through my steps and create a new project? If so, did it also fail?

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

I truely appreciate your effort. I already had a new project ready since. I think it's some sort of compiler bug showing weird errors. When it was showing error for -Swift.h file not found, closing and reopeaning xcode solved the problem. Realising I am loosing a lot of time on this, I coded the file in objc, reverse engineering the swift code. However, I'll need it to work as there is more documentation i need that's only loading in swift. Would importing it in AppDelegate make a difference instead main.h?

I’m not quite sure how to parse this. Are you saying that:

• If you create a new project, it works? And thus the problem only affects your main project?

• Or that, even if you follow the above instructions, your new project still fails?

This matters because it tells us whether there’s a general problem or a specific problem with your main project.

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

Even in the new. By the time I read your post I was already on a new project for a different reason.

OK then, what version of Xcode are you using? And on what version of macOS are you running it?

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

Adding some more details based on my current experience: My task is to convert an OBJC codebase from premium to freemium on IOS16, and I want to use the new features of StoreKit2 (originalPurchaseDate and originalAppVersion) in my objective-C code. I'm using the Storekit2 example code (https://developer.apple.com/documentation/storekit/in-app_purchase/implementing_a_store_in_your_app_using_the_storekit_api), especially the file "store.swift", and my problem was to be able to call the functions in that file from my OBJC modules. So here is what helped me:

1. Create an object in store.swift, and flag it with @objc (see below). As the object is in the swift file, it can call all the swift code. The @objc makes the object visible to the OBJC code as well.
2. Each property and each function that should be visible to OBJC must be proceeded with "@objc"

import Foundation
import StoreKit

@objc(MySwiftObject)
class MySwiftObject : NSObject {

	@objc
	var someProperty: AnyObject = "Some Initializer Val" as NSString

	override init() {
	}

	@objc
	func someFunction(someArg: Any) -> NSString {
		return "You sent me \(someArg)" as NSString
	}

	@objc
	func myAppTransaction() async {
		do {
			// Get the appTransaction.
			if #available(iOS 16.0, *) {
				let shared = try await AppTransaction.shared
				if case .verified(let appTransaction) = shared {
					// Get the major version number of the version the customer originally purchased.
					let versionComponents = appTransaction.originalAppVersion.split(separator: ".")
					let originalMajorVersion = versionComponents[0]

					if originalMajorVersion < "2" {
						// This customer purchased the app before the business model changed.
						// Deliver content that they're entitled to based on their app purchase.
					}

					else {
						// This customer purchased the app after the business model changed.

					}

				}

			} else {
				// Fallback on earlier versions

			}

		}

		catch {

			// Handle errors.

		}



	}

}

1. To make anything visible in OBJC code, we need an include file, which is auto-generated by the compiler - this was the point that I didn't understand for a long time. The name of the include file is "-Swift.h", for e.g. my app name is "dogwalk", so the include file is named "dogwalk-Swift.h", this is what you can use in the #include statement, no help from autocomplete, you have to type the full statement. See below for the OBJC example code:

#import "dogwalk-Swift.h"

	MySwiftObject * myOb = [[MySwiftObject alloc] init];

	myOb.someProperty = @"Hello World";
	NSLog(@"MyOb.someProperty: %@", myOb.someProperty);

	NSString * retString = [myOb someFunctionWithSomeArg:@"my string example"];
	NSLog(@"RetString: %@", retString);

	[myOb myAppTransactionWithCompletionHandler:^{

		NSLog(@"appTransaction completed");

	}];