Creating the RecyclerView Adapter in Kotlin

RecyclerView is among the most widely used elements in Android development. It is essentially used to display data in a list using an adapter. In this recipe, we will learn how to leverage great things in Kotlin to make RecyclerView much more efficient. We will also be using DiffUtils. It is available from 24.02. According to the documentation:

DiffUtil is a utility class that can calculate the difference between two lists and output a list of update operations that converts the first list into the second one.

The definition is self-explainatory. The notifyDatasetChanged is a very expensive operation of the adapter. The DiffUtils only updates the parts that were changed, unlike notifyDatasetChanged, which updates the whole list.

Getting ready

Create a new Android project in Android Studio. You can also clone the https://gitlab.com/aanandshekharroy/kotlin-cookbook repository and check out the 1-recycler-view-in-kotlin branch.

In this app, we will be...