Adding ObjectiveC/Swift Code to an application

You can add Objective-C/Swift source files to App_Resources/iOS/src. For Objective-C files, create a .modulemap file. To add a CocoaPod, edit App_Resources/iOS/Podfile:

App_Resources/
├─ iOS/
│  ├─ src/
│  │  ├─ Shimmer.swift
│  │  ├─ Shimmer.h
│  │  ├─ Shimmer.m
│  │  └─ module.modulemap
│  └─ Podfile
└─ ... more

Adding Swift code ​

Define the swfit file in App_Resources/iOS/src.

// HelloSwift.swift
import UIKit

class HelloSwift: NSObject {
    @objc public var stringToReturn: String = "Hello from Swift!"

    @objc public func getString() -> String {
        return stringToReturn;
    }
}

Given the example above, your JavaScript or TypeScript code can reference the Swift code by using the full class name:

const helloSwift = new HelloSwift()
helloSwift.stringToReturn = 'Custom hello from Swift!'
console.log(helloSwift.getString()) 
// prints: Custom hello from Swift!

Using @objc ​

@objc allows exposing variables and functions to use them from JS/TS, note that in the example the variables and methods have this notation.

Using @objcMembers ​

A shortcut to the @objc notation is to use the @objcMembers notation at the class level to make the entire class accessible.

// HelloSwift.swift
import UIKit

@objcMembers
class HelloSwift: NSObject {
    public var stringToReturn: String = "Hello from Swift!"

    public func getString() -> String {
        return stringToReturn;
    }
}