Initializer is inaccessable due to 'internal' protection level

Question

I have some protocols

LoginStrategy

public protocol LoginStrategy {
    func login(_ viewController: UIViewController)
    func getUserInfo(withCompletionHandler completionHandler: @escaping (_ userInfo: [String: Any]?) -> ())
    func createLoginButton(_ frame: CGRect, withCompletionHandler completionHandler: @escaping (_ loginButton: UIView) -> ())
    func getUserId() -> String
}

and two classes:

LoginProvider

public class LoginProvider {

    public let strategy: LoginStrategy

    public func login(_ viewController: UIViewController) {
        return self.strategy.login(viewController)
    }

    public func getUserInfo(withCompletionHandler completionHandler: @escaping (_ userInfo: [String: Any]?) -> ()) {
        return self.strategy.getUserInfo(withCompletionHandler: completionHandler)
    }

    public func createLoginButton(_ frame: CGRect, withCompletionHandler completionHandler: @escaping (_ loginButton: UIView) -> ()) {
        return self.strategy.createLoginButton(frame, withCompletionHandler: completionHandler)
    }

    public func getUserId() -> String {
        return self.strategy.getUserId()
    }

    public init(strategy: LoginStrategy) {
        self.strategy = strategy
    }

}

FacebookLoginStrategy

import Foundation
import FacebookCore
import FacebookLogin

public class FacebookLoginStrategy: LoginStrategy {

    public var grantedPermissions: Set<Permission>? = nil

    public var declinedPermissions: Set<Permission>? = nil

    public var userId: String = ""

    public func login(_ viewController: UIViewController) {
        let loginManager = LoginManager()
        let permissions: [ReadPermission] = [.publicProfile, .userFriends, .email]
        loginManager.logIn(permissions, viewController: viewController) { loginResult in
            switch loginResult {
            case .failed(let error):
                print(error)
            case .cancelled:
                print("User cancelled login.")
            case .success(let grantedPermissions, let declinedPermissions, let accessToken):
                self.userId = accessToken.userId ?? ""
                self.grantedPermissions = grantedPermissions
                self.declinedPermissions = declinedPermissions
                print("Logged in!")
            }
        }
    }

    public func getUserId() -> String {
        return userId
    }

    public func getUserInfo(withCompletionHandler completionHandler: @escaping (_ userInfo: [String: Any]?) -> ()) {
        let request = GraphRequest(graphPath: "me", parameters: ["fields":"email, name"], accessToken: AccessToken.current, httpMethod: .GET, apiVersion: FacebookCore.GraphAPIVersion.defaultVersion)
        request.start { (response, result) in
            switch result {
            case .success(let value):
                print(value.dictionaryValue)
                completionHandler(value.dictionaryValue)
            case .failed(let error):
                print(error)
            }
        }
    }

    public func createLoginButton(_ frame: CGRect, withCompletionHandler completionHandler: @escaping (_ loginButton: UIView) -> ()) {
        let permissions: [ReadPermission] = [.publicProfile, .userFriends, .email]
        let loginButton = LoginButton(readPermissions: permissions)
        loginButton.frame = frame
        completionHandler(loginButton)
    }
}

In my ViewController:

When I use:

let facebookLoginProvider = LoginProvider(strategy: FacebookLoginStrategy())

It says:

'FacebookLoginStrategy' is inaccessable due to 'internal' protection level

Solution 1

Just add to your FacebookLoginStrategy:

public init() {}

As long as you do not implement init() explicitly, it is marked as internal by default. You need to overwrite that permission level to be able to instantiate from outside your framework.

Solution 2

If you are running in to this in code within an XCTestCase, make sure that you have added @testable import My-Awesome-App to the top of your test file.

Solution 3

Add init method as Public access

public init() {}

Comments

[Paul Razvan Berg]

Great answer! And watch out for Swift4, it's actually an error if you don't implement it.

[jboi]

Just into the class.

[LightningStryk]

this is so dumb that Swift requires this. If I declare the whole class type public, the free init() should come as public as well

[lee]

This should a bug of Swift. It should not an error of compiler, since we had marked public for class/struct.

[jboi]

Just learned, that it also works for structs. Got the error-message, was confused, googled and found my own answer. It's getting late on a Friday...

[AndreG]

I've added public before my init and I am still getting that same message. Is there another protection?

[jboi]

Hi @AndreG , can you share some code with us? Maybe just ask your question.

[fredy]

Thank you so much.

[Peter Schorn]

@lee It's not dumb, nor is it a bug. Sometimes you don't want the initializers for a type to be public. It's easy to forget about the existence of synthesized initializers because they don't actually appear in your code. Therefore, if these initializers were public, it'd be easy to accidentally expose them outside of the module.