README.md

Template method

Define the skeleton of an algorithm in an operation, deferring some steps to subclasses. Template method lets subclasses redefine certain steps of an algorithm without changing the algorithm's structure.

Source: wikipedia.org

Swift Example

class Computer {
    func printBrandName() {
        print("Computer brand: \(brandName())")
    }
 
    func brandName() -> String {
        assertionFailure("Please provide brand name")
        return ""
    }
 }

class Apple: Computer {
    override func brandName() -> String {
        return "Apple"
    }
}

class Dell: Computer {
    override func brandName() -> String {
        return "Dell"
    }
}

Swift Usage

let apple = Apple()
apple.printBrandName()

let dell = Dell()
dell.printBrandName()

Kotlin Example

open class Computer {
    fun printBrandName() {
        println("Computer brand: " + brandName())
    }

    open fun brandName(): String {
        return "Default brand name"
    }
}

class Apple: Computer() {
    
    override fun brandName(): String {
        return "Apple"
    }
    
}

class Dell: Computer {
    override fun brandName(): String {
        return "Dell"
    }
}

Kotlin Usage

val apple = Apple()
apple.printBrandName()

val dell = Dell()
dell.printBrandName()

Summary