Container with State/Data?

[MrSkwiggs]

I want to implement a custom container which holds a reference to an AuthToken, so that I may build services which require said token.

Unfortunately, there seems to be no way to go around the static let shared = MyContainer() requirement, which renders my attempts impossible :(

Would it be possible to provide a static func shared<T>(_ constructorData: T) -> Self overload or something which would allow me to do this?

Or is there a better, Factory-ish way of providing this behaviour, that I'm not aware of?

[hmlongco]

SharedContainer requires at least one instance of a shared container. Doesn't mean you can't create multiple instances of them and ignore the shared container.

Or you can simply derive from the parent protocol, ManagedContainer.

[MrSkwiggs]

So wait, what happens if I do:

final class MyContainer: SharedContainer {
  private let token: String

  // MARK: - Do not use
  static let shared = MyContainer(token: "")
  
  static func shared(token: String) -> MyContainer {
    .init(token: token)
  }

  var myService: Factory<MyService> {
    self { .init(token: token) }
  }
}

In the case where dependencies are injected etc. How does it know which static instance to use?

[MrSkwiggs]

Ah I guess reading the code docs for this protocol, shared is used exactly for this, so it would not work in this case. But using just ManagedContainer seems to do the trick just fine, thanks 👍

[hmlongco]

Didn't have the code sample, so thought this was a different problem. If you're using Injected, etc., you still couldn't do what you want since there would be no way to tell the wrapper to pass a value through to shared.

I'd probably do...

final public class MyContainer: SharedContainer {

    public  static let shared = MyContainer()
    public let manager = ContainerManager()

    private var token: Factory<String> {
        self { /* obtain token from wherever token comes from */  }.cached
    }

    public var myService: Factory<MyService> {
        self { .init(token: token()) }
    }

}

Or if token must be passed in from the outside on initialization, change the private to internal and do something like...

// someplace early in initialization
MyContainer.shared.token.register { "SUPER SECRET TOKEN" }