inheritance.swift

import UIKit

var str = "Hello, playground"

class BaseViewController: UIViewController {
    
    var handledErrorCodes: [Int: String] = [200: "localized.title", 210: "localized.title.error"]
    
    func showError(error: NSError) {
        let code = error.code
        
        guard handledErrorCodes.keys.contains(code), let text = handledErrorCodes[code] as? String else {
            print("\(self) can't handle this error code \(code)")
            return
        }
        
        switch code {
        case 200:
            print("\(self) handle 200 code \(text)")
        case 210:
            print("\(self) handle 210 code \(text)")
        default:
            print("\(self) handle unknown code \(text)")
        }
    }
    
}

class RootViewController: BaseViewController {}

class ProfileViewController: BaseViewController {}

let error = NSError(domain: "cactussoft", code: 210, userInfo: nil)

let base = BaseViewController()
base.showError(error: error)

let root = RootViewController()
root.handledErrorCodes = [211: "localized.title", 220: "localized.title.error"]
root.showError(error: error)

let profile = ProfileViewController()
profile.handledErrorCodes = [310: "localized.title", 120: "localized.title.error"]
profile.showError(error: error)

let error211 = NSError(domain: "cactussoft", code: 211, userInfo: nil)
profile.showError(error: error211)