Syntax to Call Swift Method from Objective-C Class

Question

I am trying to call some code in a Utilities file written in swift from an objective-c file.

Right now the class in the swift file looks like this:

class ImageClass: NSObject {
public func imageFromString(name: String?) -> UIImage? {
//code to make image

return image
}
}

I am trying to call it from the Objective-C file with:

 UIImage *myImage = [ImageClass imageFromString:@"test"];

however this is giving error:

Use of undeclared identifier 'ImageClass'

I know the Utilities file is reachable from the Objective-C file because I call other methods there though using a shared Instance.

Can anyone suggest the proper way to call the code? I actually don't care if it's a class or through a sharedInstance, I just need to be able to call it.

Edit:

As suggested by @Charles Srstka, I CMD-clicked on the #import myapp.swift file, jumped to Definition, and it shows the following in the header:

- (UIImage * _Nullable)imageFromStringWithName:(NSString * _Nullable)name SWIFT_WARN_UNUSED_RESULT;

Accordingly, I tried adding WithName (which I'd forgotten) to the invocation so I have:

 UIImage *myImage = [ImageClass imageFromStringWithName:@"test"];

but am still getting error with or without @objc before method:

No known class method for selector 'imageFromStringWithName:'

Answer 1

In swift 4.2 and latest

1. Add this line to your "*.m" file:

   #import "YourProjectName-Swift.h"
   

2. Add @objc before your function:

   @objc public func imageFromString(name: String?) -> UIImage? {    
   //code to make the image
   return image
   }
   

3. Call it inside Objective-C class:

   ImageClass *imgObject = [[ImageClass alloc] init];   
   UIImage *myImage = [imgObject imageFromStringWithName:@"test"];