CODEWITHSUNDEEP
iosswift
Latcie
Latcie

Reputation: 701

Swift extension with extension

So I want to do something like:

protocol CanShowView: class where Self: UIViewController, SomeDelegate{
func someFunction()
}

extension CanShowView{
func someFunction(){
someView.SomeDelegate = self
}

Basically, I want to make sure that the protocol can only be implemented by a UIViewController that also implements the SomeDelegate protocol, but xcode is mad about the first line of code in the example.

Upvotes: 2

Views: 682

Answers (1)

farzadshbfn
farzadshbfn

Reputation: 2748

If you're using Swift 4+ :

protocol CanShowView {
    func someFunction()
}

extension CanShowView where Self: UIViewController & SomeDelegate {
    func someFunction() {
        someView.SomeDelegate = self
    }
}

If Swift 3.0:

protocol CanShowView {
    func someFunction()
}

extension CanShowView where Self: UIViewController, Self: SomeDelegate {
    func someFunction() {
        someView.SomeDelegate = self
    }
}

This is the right way to add conditional extensions, not in protocol definition. If you want to limit protocol to some constraint, best way to go is using associatedTypes.

Upvotes: 6

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