Swift 4.3 - protocols passing data between 2 files - swift

Question

I am struggling with understanding how protocols work. I have 2 files and want to use protocol to pass data... Here's what I am doing:
In ViewController.swift
protocol workingProtocol { func myFunc(strValue: String)}
class ViewController: UIViewController {
var interactor = workingProtocol
#objc func doneBtn() {
interactor.myFunc(strValue: "str")
}
}
In Interactor.swift
class Interactor {
func myFunc(strValue: String) {
print(strValue)
}
}
The data is not printing from Interactor.swift

Answer 1

Unfortunately I can't see how you inject interaction class, also your code has some problem with syntax. Here is how it should look:
protocol WorkingProtocol: AnyObject {
func myFunc(strValue: String)
}
final class ViewController: UIViewController {
var interactor: WorkingProtocol
#objc func doneBtn() {
interactor.myFunc(strValue: "str")
}
}
final class Interactor: WorkingProtocol {
func myFunc(strValue: String) {
print(strValue)
}
}
And how to use:
let interactor: WorkingProtocol = Interactor()
let vc = ViewController(interactor: interactor)
vc.doneBtn()

Answer 2

Protocols defines a blueprint of methods, properties and other requirements that suite a piece of functionality.
This is an example about how it works based on your code
protocol ProtocolName {
func functionName(strValue: String)
}
class ViewController {
var interactor: ProtocolName? = nil
#objc
fileprivate func doneBtn() {
interactor?.functionName(strValue: "Passing data to interactor using protocols")
}
}
class Interactor: ProtocolName {
func functionName(strValue: String) {
print("Showing value\n", strValue)
}
}
let interactor = Interactor()
let viewController = ViewController()
viewController.interactor = interactor
viewController.doneBtn()
Another example:
protocol ProtocolName {
func functionName(strValue: String)
}
class ViewController1 {
let interactor = Interactor1()
/// Init or viewDidLoad() if you're using ViewController classes.
init() {
interactor.delegate = self
}
}
extension ViewController1: ProtocolName {
func functionName(strValue: String) {
print("Printing the value: \(strValue)")
}
}
class Interactor1 {
var delegate: ProtocolName?
func someAction() {
delegate?.functionName(strValue: "Executed action in interactor.")
}
}
let vc = ViewController1()
vc.interactor.someAction()