How to correct implement provider logic using generics in Swift - swift

Question

I try to implement logic where some different objects can receive their unique configs.
I have a lot of objects with different types, which can request their own configuration object.
//Provider
protocol ConfigProvider {
func config<R: ConfigReciever>(for reciever: R) -> R.ConfigType
}
class Factory {
}
extension Factory: ConfigProvider {
func config<R: ConfigReciever>(for reciever: R) -> R.ConfigType {
//How switch?
return Config1(info: "hey") as! R.ConfigType
}
}
//Reciever
protocol ConfigReciever: class {
associatedtype ConfigType
var dataSource: ConfigProvider? { get set }
}
struct Config1 {
let info: String
}
class Object1: ConfigReciever {
typealias ConfigType = Config1
var dataSource: ConfigProvider?
func execute() {
let config = dataSource?.config(for: self)
print("\(config!.info)")
}
}
But have some problems with correct implement Provider logic.
I don't know how switch reciever to create correct Config type.
Is this any options?
I know, that i can make this without generics (for example with enum of configTypes), but i don't want to make unnecessary casts.

Answer 1

I would suggest using an intermediate protocol
// Wrapper container
protocol Container { }
extension String: Container { }
extension Int: Container { }
// Implementation
//Provider
protocol ConfigProvider {
func config<R>(for reciever: R) -> Configuration where R : ConfigReciever, R.ConfigType: Configuration
}
class Factory { }
extension Factory: ConfigProvider {
func config<R>(for reciever: R) -> Configuration where R : ConfigReciever, R.ConfigType: Configuration {
return Config1(info: "hey")
}
}
//Reciever
protocol ConfigReciever: class {
associatedtype ConfigType
var dataSource: ConfigProvider? { get set }
}
protocol Configuration {
var info: Container { get set }
}
struct Config1: Configuration {
var info: String
}
class Object1: ConfigReciever {
typealias ConfigType = Config1
var dataSource: ConfigProvider?
func execute() {
let config = dataSource?.config(for: self)
// here you should case into wanted structure:
if let stringInfo = config?.info as? String {
print("\(stringInfo)")
}
}
}
let factory = Factory()
let obj = Object1()
obj.dataSource = factory
obj.execute()