CODEWITHSUNDEEP
swiftstaticsingletonsubclass
Sean256
Sean256

Reputation: 3099

In Swift, is there a keyword like self but for the class?

class mySuperClass{
    static var sharedInstance = mySuperClass()
    var test = "hello"
}

In this little snippet, I am setting a static var to mySuperClass() to create a simple singleton.

Is there a way to do this without using the class name mySuperClass?

I ask, because I want to subclass something like this and have the subclass create a sharedInstance of itself and NOT of the super class which is what it does.

Full code here (playground-able):

import Cocoa

class mySuperClass{
    static var sharedInstance = mySuperClass()
    var test = "hello"
}

class mySubClass:mySuperClass{
    override init() {
        super.init()
        test = "hello from subclass"
    }
}


print(mySuperClass.sharedInstance.test)

print(mySubClass.sharedInstance.test) //prints test from mySuperClass not subClass

Upvotes: 2

Views: 86

Answers (1)

Luca Angeletti
Luca Angeletti

Reputation: 59526

In other words you want to subclass a Singleton.

Let me know if this does solve your problem.

class MySuperClass {
    private static let superClassInstance = MySuperClass()
    class var sharedInstance: MySuperClass { return superClassInstance }
    private init() { }

    var test = "hello"
}

class MySubClass: MySuperClass {
    private static let subClassInstance = MySubClass()
    override class var sharedInstance: MySubClass { return subClassInstance }

    private override init() {
        super.init()
        test = "hello from subclass"
    }
}


print(MySuperClass.sharedInstance.test) // "hello"
print(MySubClass.sharedInstance.test) // "hello from subclass"

Upvotes: 2

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