Develop Reusable & Customizable Code with Kotlin Delegation

Developing Reusable and Customizable Code with Kotlin Delegation

Using the Kotlin programming language to develop reusable and customizable code is becoming increasingly popular. This is due to its concise syntax and the ability to create powerful abstractions without the use of excessive boilerplate code. One of the most powerful abstractions available in Kotlin is delegation. In this post, we will explore what delegation is and how to implement it with Kotlin.

What is Delegation?

Delegation is a design pattern in which an object (the delegate) can be used to perform certain tasks on behalf of another object (the delegator). By using delegation, you can remove the need to duplicate code in multiple classes, allowing you to write more efficient and reusable code. The delegate does not need to know anything about the delegator, making it a very useful tool for code abstraction.

Implementing Delegation with Kotlin

Kotlin provides a simple syntax for creating and using delegates. Let’s start by looking at an example of a basic delegate. In this example, we have two classes: the delegator and the delegate.

interface Delegate {
    fun doSomething()
}
 
class Delegator {
    private val delegate = object: Delegate {
        override fun doSomething() {
            // Do something here
        }
    }
 
    fun callDelegate() {
        delegate.doSomething()
    }
}

In this example, the Delegator class instantiates an anonymous object that implements the Delegate interface. It then refers to this object using the delegate property. When the callDelegate() method is called, the delegate’s doSomething() method is executed.

Kotlin makes it even easier to implement delegation with the use of the by keyword. Using the by keyword, we can declare a property that will delegate its methods and properties to an instance of a class. Let’s take a look at how this works in our example:

interface Delegate {
    fun doSomething()
}
 
class Delegator(val delegate: Delegate) {
    fun callDelegate() {
        delegate.doSomething()
    }
}
 
val delegator = Delegator(object: Delegate{
    override fun doSomething() {
        // Do something here
    }
})

In this example, the delegator object has a property named delegate that delegates its methods and properties to an anonymous object that implements the Delegate interface. This way, we can instantiate our delegator object without having to explicitly pass in an instance of the delegate.

Conclusion

Delegation is an extremely powerful tool for code abstraction, and Kotlin makes it easy to implement. By using the by keyword, you can easily create reusable and customizable code that is both concise and efficient. If you’re looking to write more efficient code, delegation is definitely something you should consider.