How to set a readwrite internal, readonly external property in protocol - ios

Question

I have some classes have same behaviors, they all have
properties > savedPath: String, items: [String], currentItem: [String]
functions > archive(with items: [String]), unarchive()
So I create a protocol.swift and let those classes conform this protocol to implement these common behavior.But, in my case, i want:
items is a readonly external, readwrite internal
archive/unarchive are private func
i tried to use private(set) before items, private before archive/unarchive and some errors showed up.
Is there any flexible solutions to fix that?
before without protocol
class SampleClass {
private(set) var items: [SampleModel] {
set {
archive(with: newValue)
} get {
return unarchive()
}
}
func archive(with addresses: [SampleModel]) { ... }
func unarchive() -> [SampleModel] { ... }
}
after try to use protocol to satisfy
protocol SampleProtocol {
associatedtype Item: Switchable
var savedPath: String { get }
var items: [Item] { get }
var currentItem: Item? { get }
func archive(with items: [Item])
func unarchive() -> [Item]
}

Answer 1

You must remove any private function from protocol (Since it's meaningless). Nothing is private inside a protocol( setter or function or etc. )
protocol SampleProtocol {
associatedtype Item: Switchable
var savedPath: String { get }
var items: [Item] { get }
var currentItem: Item? { get }
}
And you should then implement the class access controls like this:
class SampleClass {
private(set) var items: [SampleModel] {
set {
archive(with: newValue)
} get {
return unarchive()
}
}
private func archive(with addresses: [SampleModel]) { /* ... */ }
private func unarchive() -> [SampleModel] { /* ... */ }
}